10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended September 30, 2024

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from ______________ to _______________

Commission File Number 001-35521

CLEARSIGN TECHNOLOGIES CORPORATION

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
incorporation or organization) 26-2056298
(I.R.S. Employer
Identification No.)

8023 E. 63rd Place, Suite 101

Tulsa, Oklahoma 74133

(Address of principal executive offices)

(Zip Code)

(918) 236-6461

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	CLIR	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ⌧ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period than the registrant was required to submit such files). Yes ⌧ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☐	Accelerated filer ☐
Non-accelerated filer ⌧	Smaller reporting company ☒
	Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐  No ⌧

As of November 6, 2024, the issuer has 50,234,407 shares of common stock, par value $0.0001, issued and outstanding.

TABLE OF CONTENTS

PART I	FINANCIAL INFORMATION
Item 1.	Financial Statements (unaudited)
	Condensed Consolidated Balance Sheets as of September 30, 2024 and December 31, 2023	1
	Condensed Consolidated Statements of Operations and Comprehensive Loss for the three and nine months ended September 30, 2024 and 2023	2
	Condensed Consolidated Statements of Stockholders’ Equity for the three month periods during the nine months ended September 30, 2024 and 2023	3
	Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2024 and 2023	5
	Notes to Condensed Consolidated Financial Statements	6
Item 2.	Management’s Discussion and Analysis of Financial Conditions and Results of Operations	22
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	29
Item 4.	Controls and Procedures	29
PART II	OTHER INFORMATION	30
Item 1.	Legal Proceedings	30
Item 1A.	Risk Factors	30
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	31
Item 3.	Defaults Upon Senior Securities	31
Item 4.	Mine Safety Disclosures	32
Item 5.	Other Information	32
Item 6.	Exhibits	32
	SIGNATURES	34

PART I - FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

ClearSign Technologies Corporation and Subsidiary

Condensed Consolidated Balance Sheets

(Unaudited)

(in thousands, except share and per share data)	September 30,		December 31,
	2024		2023
ASSETS
Current Assets:
Cash and cash equivalents	$	14,486	$	5,684
Accounts receivable		749		287
Contract assets		149		188
Prepaid expenses and other assets		610		350
Total current assets		15,994		6,509
Fixed assets, net		245		275
Patents and other intangible assets, net		855		836
Total Assets	$	17,094	$	7,620
LIABILITIES AND STOCKHOLDERS' EQUITY
Current Liabilities:
Accounts payable and accrued liabilities	$	1,486	$	366
Current portion of lease liabilities		82		71
Accrued compensation and related taxes		401		703
Contract liabilities		174		1,116
Total current liabilities		2,143		2,256
Long Term Liabilities:
Long term lease liabilities		128		172
Total liabilities		2,271		2,428
Commitments and contingencies (Note 9)
Stockholders’ Equity:
Preferred stock, $0.0001 par value, zero shares issued and outstanding		—		—
Common stock, $0.0001 par value, 50,234,407 and 38,687,061 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively		5		4
Additional paid-in capital		112,686		98,922
Accumulated other comprehensive loss		(16)		(17)
Accumulated deficit		(97,852)		(93,717)
Total stockholders' equity		14,823		5,192
Total Liabilities and Stockholders' Equity	$	17,094	$	7,620

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

1

ClearSign Technologies Corporation and Subsidiary

Condensed Consolidated Statements of Operations and Comprehensive Loss

(Unaudited)

(in thousands, except share and per share data)	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
Revenues	$	1,859	$	85	$	3,006	$	1,129
Cost of goods sold		1,308		61		1,976		870
Gross profit		551		24		1,030		259
Operating expenses:
Research and development		329		93		1,012		440
General and administrative		1,655		1,428		4,840		4,649
Total operating expenses		1,984		1,521		5,852		5,089
Loss from operations		(1,433)		(1,497)		(4,822)		(4,830)
Other income, net
Interest income		146		85		284		237
Government assistance		131		38		395		145
Gain from sale of assets		—		—		—		5
Other income, net		1		42		8		204
Total other income, net		278		165		687		591
Net loss	$	(1,155)	$	(1,332)	$	(4,135)	$	(4,239)
Net loss per share - basic and fully diluted	$	(0.02)	$	(0.03)	$	(0.09)	$	(0.11)
Weighted average number of shares outstanding - basic and fully diluted		54,714,910		38,562,127		46,986,914		38,459,313
Comprehensive loss
Net loss	$	(1,155)	$	(1,332)	$	(4,135)	$	(4,239)
Foreign-exchange translation adjustments, net of taxes		5		(1)		1		(13)
Comprehensive loss	$	(1,150)	$	(1,333)	$	(4,134)	$	(4,252)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

2

ClearSign Technologies Corporation and Subsidiary

Condensed Consolidated Statements of Stockholders’ Equity

For the Three Month Periods During the Nine Months Ended September 30, 2024 and 2023

(Unaudited)

						Accumulated Other				Total
(in thousands, except per share data)	Common Stock			Additional		Comprehensive		Accumulated		Stockholders’
	Shares	Amount		Paid-In Capital			Loss	Deficit		Equity
Balances at December 31, 2023	38,687	$	4	$	98,922	$	(17)	$	(93,717)	$	5,192
Share-based compensation	67		—		67		—		—		67
Tax withholdings related to share-based compensation	(22)		—		(16)		—		—		(16)
Fair value of stock issued in payment of accrued compensation	307		—		326		—		—		326
Shares issued for services	4		—		3		—		—		3
Foreign-exchange translation adjustment	—		—		—		(3)		—		(3)
Net loss	—		—		—		—		(1,108)		(1,108)
Balances at March 31, 2024	39,043		4		99,302		(20)		(94,825)		4,461
Share-based compensation	256		—		344		—		—		344
Tax withholdings related to share-based compensation	(11)		—		(13)		—		—		(13)
Shares issued for services	4		—		3		—		—		3
Issuance of common stock in public offering, net of expenses	5,314		1		2,390		—		—		2,391
Issuance of warrants in public offering, net of expenses	—		—		1,831		—		—		1,831
Issuance of common stock in private placement, net of expenses	2,250		—		865		—		—		865
Issuance of prefunded warrants in private placement, net of expenses	—		—		1,214		—		—		1,214
Issuance of warrants in private placement, net of expenses	—		—		2,389		—		—		2,389
Issuance of common stock for participation right exercise, net of expenses	3,350		—		1,447		—		—		1,447
Issuance of prefunded warrants for participation right exercise, net of expenses	—		—		580		—		—		580
Issuance of warrants for participation right exercise, net of expenses	—		—		2,250		—		—		2,250
Foreign-exchange translation adjustment	—		—		—		(1)		—		(1)
Net loss	—		—		—		—		(1,872)		(1,872)
Balances at June 30, 2024	50,206		5		112,602		(21)		(96,697)		15,889
Share-based compensation	—		—		73		—		—		73
Tax withholdings related to share-based compensation	—		—		(9)		—		—		(9)
Shares issued for services	29		—		20		—		—		20
Foreign-exchange translation adjustment	—		—		—		5		—		5
Net loss	—		—		—		—		(1,155)		(1,155)
Balances at September 30, 2024	50,235	$	5	$	112,686	$	(16)	$	(97,852)	$	14,823

3

ClearSign Technologies Corporation and Subsidiary

Condensed Consolidated Statements of Stockholders’ Equity

For the Three Month Periods During the Nine Months Ended September 30, 2024 and 2023

(Unaudited)

						Accumulated Other				Total
(in thousands, except per share data)	Common Stock			Additional		Comprehensive		Accumulated		Stockholders'
	Shares	Amount		Paid-In Capital			Loss	Deficit		Equity
Balances at December 31, 2022	38,023	$	4	$	98,079	$	(8)	$	(88,523)	$	9,552
Share-based compensation	223		—		227		—		—		227
Fair value of stock issued in payment of accrued compensation	296		—		234		—		—		234
Shares issued for services ($0.66 per share)	4		—		3		—		—		3
Foreign-exchange translation adjustment	—		—		—		—		—		—
Net loss	—		—		—		—		(1,429)		(1,429)
Balances at March 31, 2023	38,546		4		98,543		(8)		(89,952)		8,587
Share-based compensation	—		—		59		—		—		59
Shares issued upon exercise of options ($0.54 per share)	12		—		—		—		—		—
Shares issued for services ($0.66 per share)	4		—		2		—		—		2
Foreign-exchange translation adjustment	—		—		—		(12)		—		(12)
Net loss	—		—		—		—		(1,478)		(1,478)
Balances at June 30, 2023	38,562		4		98,604		(20)		(91,430)		7,158
Share-based compensation	—		—		119		—		—		119
Shares issued for services ($0.66 per share)	4		—		2		—		—		2
Foreign-exchange translation adjustment	—		—		—		(1)		—		(1)
Net loss	—		—		—		—		(1,332)		(1,332)
Balances at September 30, 2023	38,566	$	4	$	98,725	$	(21)	$	(92,762)	$	5,946

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

4

ClearSign Technologies Corporation and Subsidiary

Condensed Consolidated Statements of Cash Flows

(Unaudited)

(in thousands)	For the Nine Months Ended September 30,
	2024		2023
Cash flows from operating activities:
Net loss	$	(4,135)	$	(4,239)
Adjustments to reconcile net loss to net cash used in operating activities:
Common stock issued for services		26		7
Share-based compensation		484		419
Reserve for share-based compensation tax withholdings		(38)		—
Depreciation and amortization		138		231
Impairment of intangible assets		17		14
Gain from sale of fixed assets		—		(5)
Right-of-use asset amortization		64		105
Realized gain from marketable securities		—		(79)
Lease amendments		(3)		(14)
Change in operating assets and liabilities:
Contract assets		39		13
Accounts receivable		(462)		(8)
Prepaid expenses and other assets		(260)		(116)
Accounts payable, accrued liabilities, and lease liabilities		1,091		6
Accrued compensation and related taxes		23		329
Contract liabilities		(942)		1,554
Net cash used in operating activities		(3,958)		(1,783)
Cash flows from investing activities:
Acquisition of fixed assets		(18)		—
Disbursements for patents and other intangible assets		(159)		(95)
Proceeds from sale of fixed assets		—		5
Purchases of held-to-maturity short-term U.S. treasuries		—		(2,162)
Redemption of held-to-maturity short-term U.S. treasuries		—		4,847
Net cash provided by (used in) investing activities		(177)		2,595
Cash flows from financing activities:
Proceeds from issuance of common stock, net of offering costs		12,967		—
Taxes paid related to vesting of restricted stock units		(31)		(15)
Net cash provided by (used in) financing activities		12,936		(15)
Effect of exchange rate changes on cash and cash equivalents		1		(13)
Net change in cash and cash equivalents		8,802		784
Cash and cash equivalents, beginning of period		5,684		6,451
Cash and cash equivalents, end of period	$	14,486	$	7,235
Supplemental disclosure of cash flow information:
Officer and employee equity awards for prior year accrued compensation	$	326	$	234
Prior year prepaid expenses repurposed to fixed assets as demonstration equipment	$	—	$	209
Non-cash impact of new lease	$	32	$	34

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

5

ClearSign Technologies Corporation

Notes to Unaudited Condensed Consolidated Financial Statements

Note 1 – Organization and Description of Business

ClearSign Technologies Corporation (“ClearSign” or the “Company”) designs and develops products and technologies for the purpose of decarbonization and improving key performance characteristics of industrial and commercial systems, including operational performance, energy efficiency, emission reduction, safety, and overall cost-effectiveness. The Company’s patented technologies are designed to be embedded in established original equipment manufacturers (“OEM”) products as ClearSign Core™ and ClearSign Eye™ and other sensing configurations in order to enhance the performance of combustion systems and fuel safety systems in a broad range of markets. These markets include energy (upstream oil production and down-stream refining), commercial/industrial boiler, chemical, petrochemical, transport and power industries. The Company’s primary technology is its ClearSign Core technology, which achieves very low emissions without the need of selective catalytic reduction.

The Company was originally incorporated in the State of Washington in 2008. During January 2022, the Company relocated its headquarters from Seattle, Washington to Tulsa, Oklahoma. Effective June 15, 2023, the Company changed its state of incorporation to Delaware. On July 28, 2017, the Company incorporated a subsidiary, ClearSign Asia Limited, in Hong Kong to represent the Company’s business and technological interests throughout Asia. Through ClearSign Asia Limited, the Company has established a wholly foreign owned enterprise (“WFOE”) in China – ClearSign Combustion (Beijing) Environmental Technologies Co., LTD. On August 22, 2024, the Company’s Board of Directors (the “Board”) authorized management to move forward with filing for dormancy with Chinese regulators to suspend the Company’s Beijing, China operations. A dormancy filing allows the Company to keep its China legal entity in a suspended status for up to three years. The Company can revive its China operations at any time during those three years with minimal cost impact. Based on the Company’s current project plans, it expects to file for dormancy on or near December 31, 2024.

Unless otherwise stated or the context otherwise requires, the terms “we,” “us,” “our,” “ClearSign” and the “Company” refer to ClearSign Technologies Corporation and its subsidiary, ClearSign Asia Limited.

Note 2 – Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for Form 10-Q. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet at December 31, 2023 has been derived from the Company’s audited consolidated financial statements as of that date.

In the opinion of management, these condensed consolidated financial statements reflect all normal recurring and other adjustments necessary for a fair presentation. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Operating results for interim periods are not necessarily indicative of operating results for an entire fiscal year or any other future periods.

The accompanying unaudited condensed consolidated financial statements include the accounts of ClearSign and its subsidiary. Intercompany balances and transactions have been eliminated in consolidation.

6

Liquidity

The Annual Report on Form 10-K filed with the SEC on April 1, 2024, contained a “going concern” note, which raised substantial doubt about our ability to continue as a going concern. We believe that we have alleviated the substantial doubt by selling equity securities on April 23, 2024, May 15, 2024, and June 24, 2024, which resulted in aggregate gross proceeds of approximately $14.2 million and net proceeds of approximately $13.0 million, after broker discounts and related fees. Refer to “Note 7 – Equity” for further details about the offerings effectuated during the nine months ended September 30, 2024.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Research and Development

The cost of research and development is expensed as incurred. Research and development costs consist of salaries, benefits, share-based compensation, consumables, and consulting fees, including costs to develop and test prototype equipment and parts. Research and development costs have been offset by funds received, if any, from strategic partners in cost sharing, collaborative projects. During the three and nine months ended September 30, 2024, the Company received $28 thousand and $135 thousand, respectively, from these arrangements. During the three and nine months ended September 30, 2023, the Company received $60 thousand from these arrangements.

Foreign Operations

The accompanying unaudited condensed consolidated balance sheets as of September 30, 2024 and December 31, 2023 include assets amounting to approximately $209 thousand and $334 thousand, respectively, relating to the operations of ClearSign Asia Limited. The Beijing registered capital requirement is $350 thousand, which is required to be paid by June 30, 2032, and of which $211 thousand has been paid as of September 30, 2024. On August 22, 2024, the Board authorized management to move forward with filing for dormancy with Chinese regulators to suspend the Company’s Beijing, China operations. A dormancy filing allows the Company to keep its China legal entity in a suspended status for up to three years. The Company can revive its China operations at any time during those three years with minimal cost impact. Based on the Company’s current project plans, it expects to file for dormancy on or near December 31, 2024. We will incur one-time non-recurring costs related to this project for severance and related benefit costs, equipment disposal and shipment costs, and legal filing fees. During the three months ended September 30, 2024, we recorded a one-time non-recurring $394 thousand accrual estimate related to our decision to suspend our China operations.

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). ASU 2023-07 requires expanded disclosures about reportable segments including additional information on segment expenses, expanded interim period disclosures, and an explanation of how the chief operating decision maker utilizes segment information in evaluating segment performance. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. We are currently assessing the impact that the adoption of ASU 2023-07 will have on the disclosures in our consolidated financial statements.

In December 2023, the FASB issued ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”). The FASB issued ASU 2023-09 to enhance the transparency and decision-making usefulness of income tax disclosures by requiring additional information on an entity's tax rate reconciliation, as well as

7

income taxes paid. ASU 2023-09 is effective for our reporting period beginning January 1, 2025. We are currently assessing the impact that the adoption of ASU 2023-09 will have on the disclosures in our consolidated financial statements.

Note 3 – Fixed Assets

Fixed Assets

Fixed assets are summarized as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Office furniture and equipment	$	78	$	60
Leasehold improvements		43		43
		121		103
Accumulated depreciation and amortization		(80)		(63)
		41		40
Operating lease ROU assets, net		204		235
Total	$	245	$	275

Depreciation expense for the three and nine months ended September 30, 2024 was $4 thousand and $15 thousand, respectively.

Depreciation expense for the three and nine months ended September 30, 2023 was $41 thousand and $122 thousand, respectively.

Leases

The Company leases office space in Tulsa, Oklahoma, Seattle, Washington, and Beijing, China. During the nine months ended September 30, 2024 and 2023, the Company renewed its Beijing, China lease for 13 months with monthly rent at approximately $3 thousand. As a result of these renewals, the Company increased the right-of-use (“ROU”) asset and lease liability by $32 thousand and $34 thousand during the nine months ended September 30, 2024 and 2023, respectively.

The Company exited our long term Seattle operating lease on September 30, 2023. During October 2023, the Company entered into a sub-lease agreement to rent office space in Seattle for approximately $2 thousand per month for twelve months. We renewed the twelve month Seattle sub-lease during October 2024 with substantially the same terms. The Tulsa and Beijing leases are classified as operating leases, with remaining terms ranging from less than twelve months to approximately four years; contractual language requires renewal negotiations to occur at or near termination. These leases are normal and customary for office space, in that, contractual guarantees exist requiring the lessee return the premises to its original functional state. The Company did not incur restoration expenses for the three and nine months ended September 30, 2024. The Company did not incur restoration expenses for the three months ended September 30, 2023, and incurred $31 thousand for the nine months ended September 30, 2023.

The Tulsa lease contains fixed annual lease payments that increase annually by 2%. The Seattle, Tulsa, and Beijing total monthly minimum rent is approximately $10 thousand. Operating lease costs for the three and nine months ended September 30, 2024 were $25 thousand and $73 thousand, respectively. Operating lease costs for the three and nine months ended September 30, 2023 were $35 thousand and $117 thousand, respectively.

8

Supplemental balance sheet information related to operating leases is as follows:

		September 30,			December 31,
(in thousands)		2024			2023
Operating lease ROU assets, net	$	204		$	235
Lease Liabilities:
Current lease liabilities	$	82		$	71
Long term lease liabilities		128			172
Total lease liabilities	$	210		$	243
Weighted average remaining lease term (in years):		2.7			2.4
Weighted average discount rate:		5.3	%		5.2	%

Supplemental cash flow information related to operating leases is as follows:

	For the Nine Months Ended
	September 30,
(in thousands)		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used in operating leases	$	73	$	134
Non-cash impact of new leases and lease modifications
Change in operating lease liabilities	$	29	$	25
Change in operating lease ROU assets	$	32	$	39

Minimum future payments under the Company’s operating lease liabilities as of September 30, 2024 are as follows:

	Discounted		Payments
	lease		due under
(in thousands)	liability		lease
	payments		agreements
2024 (remaining 3 months)	$	22	$	24
2025		75		82
2026		63		67
2027		50		52
Total	$	210	$	225

At September 30, 2024, $15 thousand of our future minimum lease payments represents interest.

9

Note 4 – Patents and Other Intangible Assets

Patents and other intangible assets are summarized as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Patents
Patents pending	$	351	$	477
Issued patents		1,011		810
		1,362		1,287
Trademarks
Trademarks pending		—		4
Registered trademarks		86		86
		86		90
Other		8		8
		1,456		1,385
Accumulated amortization		(601)		(549)
	$	855	$	836

Amortization expense for the three and nine months ended September 30, 2024 was $43 thousand and $123 thousand, respectively. Amortization expense for the three and nine months ended September 30, 2023 was $32 thousand and $109 thousand, respectively.

Future amortization expense associated with issued patents and registered trademarks as of September 30, 2024 is as follows:

(in thousands)
2024 (remaining 3 months)	$	41
2025		151
2026		121
2027		98
2028		62
Thereafter		23
	$	496

The amortization life for patents ranges between three to five years, with trademark lives set at ten years. The Company does not amortize patents or trademarks classified as pending.

During the three and nine months ended September 30, 2024 and 2023, the Company assessed its patent and trademark assets for impairment. The Company incurred $17 thousand impairment costs for the three and nine months ended September 30, 2024. The Company did not incur impairment costs for the three months ended September 30, 2023, and incurred $14 thousand impairment costs for the nine months ended September 30, 2023. The Company also evaluated its strategic approach to the pursuit and protection of its intellectual property. It is the intent of the Company to continue to pursue intellectual property protection.

If the Company identifies certain assets where the intellectual property does not directly align with its core technology, the Company will impair the intangible asset and write-off the asset as an expense.

Note 5 – Revenue, Contract Assets and Contract Liabilities

The Company recognized $1,859 thousand of revenues and $1,308 thousand of cost of goods sold during the three months ended September 30, 2024. The revenue and cost of goods sold predominantly relate to the delivery of multiple

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process burners to a single customer. The delivery of products constitutes performance obligations per Accounting Standards Codification (“ASC”) 606.

The Company recognized $3,006 thousand of revenues and $1,976 thousand of cost of goods sold during the nine months ended September 30, 2024. The revenue and cost of goods sold predominantly relate to the Company’s process burner product line. The Company delivered multiple burners for different customers, successfully completed engineering feasibility studies including computational fluid dynamic analysis, and fulfilled multiple spare parts orders. These products and services constitute performance obligations per ASC 606.

The Company recognized $85 thousand of revenues and $61 thousand of cost of goods sold during the three months ended September 30, 2023. The revenue and cost of goods sold relate to a sale of our boiler burner product line.

The Company recognized $1,129 thousand of revenues and $870 thousand of cost of goods sold during the nine months ended September 30, 2023. The revenue and cost of goods sold predominantly relate to the Company’s process burner product line, where the Company successfully completed a burner performance customer witness test, which represented a contractual performance obligation per ASC 606.

The Company had contract assets of $149 thousand and $188 thousand at September 30, 2024 and December 31, 2023, respectively. The Company had contract liabilities of $174 thousand and $1,116 thousand at September 30, 2024 and December 31, 2023, respectively. Of the $1,116 thousand contract liability balance at December 31, 2023, the Company recognized revenue of $772 thousand and $1,025 thousand during the three and nine months ended September 30, 2024, respectively.

Note 6 – Product Warranties

A summary of the Company’s warranty liability activity, which is included in accrued liabilities in the accompanying consolidated balance sheets as of September 30, 2024 and December 31, 2023, is as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Warranty liability at beginning of year	$	110	$	5
Accruals		268		105
Payments		(114)		—
Changes in accrual related to expirations		(3)		—
Warranty liability at end of period	$	261	$	110

Note 7 – Equity

Common Stock and Preferred Stock

The Company is authorized to issue 87.5 million shares of common stock and 2.0 million shares of preferred stock. Preferences, limitations, voting powers and relative rights of any preferred stock to be issued may be determined by the Board. The Company has not issued any shares of preferred stock.

In July 2018, in connection with a private placement of the Company’s common stock pursuant to a Stock Purchase Agreement, the Company granted clirSPV LLC (“clirSPV”) a right to purchase certain new equity securities that the Company sells for purpose of raising capital on terms and conditions no different from those offered to other purchasers (the “Participation Right”), so that clirSPV could maintain a 19.99% percentage ownership of the Company’s outstanding common stock. In no event may the Participation Right be exercised to the extent it would cause clirSPV or any of its affiliates to beneficially own 20% or more of the Company’s then outstanding common stock.

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In May 2022, in connection with a waiver of the Participation Right’s notice requirements and other related closing mechanics for such Participation Right (the “Waiver”) the Company and clirSPV, agreed that the Participation Right may be extended from December 31, 2023, to such date that the holders of two-thirds of the outstanding units of clirSPV agree to extend each such holder’s existing agreement that he/she/it will have no right to force a redemption of his/her/its interests in clirSPV (the “Redemption Right”); provided, however, that the Participation Right could not be extended to a date later than June 30, 2027. On December 30, 2023, the Company received notice from clirSPV that the holders of at least two-thirds of the outstanding units of clirSPV agreed to extend the waiver of the Redemption Right until December 31, 2024. Accordingly, the Participation Right will now expire on December 31, 2024.

The Company has an At-The-Market (“ATM”) program pursuant to a Sales Agreement with Virtu Americas LLC, as sales agent, dated December 23, 2020 (the “Sales Agreement”), pursuant to which the Company may sell shares of common stock with an aggregate offering price of up to $8.7 million. On March 18, 2024, the Company filed a prospectus supplement suspending the ATM program. The Company will not make any sales of its common stock pursuant to the Sales Agreement unless and until a new prospectus supplement is filed with the SEC; however, the Sales Agreement remains in full force and effect. During the nine months ended September 30, 2024, the Company issued zero shares of its common stock from the ATM program. As of September 30, 2024, the Company has cumulatively issued approximately 1.6 million shares of common stock under the ATM program, at an average price of $3.84 per share. Gross proceeds totaled approximately $6.1 million and net cash proceeds was approximately $5.9 million.

The Company is currently subject to the SEC’s “baby shelf rules,” which prohibit companies with a public float of less than $75 million from issuing securities under a shelf registration statement in excess of one-third of such company’s public float in a 12-month period. These rules may limit future issuances of shares by the Company under our “shelf” registration statement on Form S-3, the ATM program or other securities offerings.

Equity Offerings 

Public Offering 

On April 23, 2024, we completed an underwritten public offering (the “Public Offering”), pursuant to which we sold approximately 4,621 thousand shares of our common stock and 4,621 thousand redeemable warrants (the “Public Warrants”) at a price of $0.91 per share of common stock and $0.01 for the accompanying Public Warrant. On May 15, 2024, Public Ventures, LLC (“Public Ventures”), the underwriter of the Public Offering, exercised its over-allotment option in full to purchase an additional 693 thousand shares of common stock and 693 thousand Public Warrants. After deducting customary professional service fees, the net proceeds from the Public Offering amounted to approximately $4,222 thousand.  

Each Public Warrant has an exercise price of $1.05 per share and is exercisable for a period of five years starting from the date of its issuance. Holders of the Public Warrants are not able to exercise their warrants on a cashless basis. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting the Company’s common stock. We have the option, but not the obligation, to redeem the Public Warrants anytime between issuance and expiration, at a price of $0.01 per Public Warrant, provided that the closing price of the common stock reported equals or exceeds $2.275 (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) per share for any 20 business days within a 30 consecutive business-day period.  

In connection with the Public Offering, we also issued approximately 425 thousand warrants to Public Ventures (the “Underwriter Warrants”), as consideration for the services provided as underwriter for the Public Offering. The Underwriter’s Warrants are exercisable at a per share exercise price of $1.1375 commencing 180 days from April 19, 2024, and expire on their fifth year anniversary. The Underwriter’s Warrants can be exercised on a cashless basis based on a formula set forth therein and are non-redeemable. 

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The shares of common stock and Public Warrants issued in the Public Offering have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

(in thousands)		Allocated Amount
Common Stock	$	2,391
Public Warrants		1,831
	$	4,222

In determining the fair values of the Public Warrants and Underwriter Warrants, we used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

The Underwriter Warrants issued in connection with the Public Offering have been accounted for as a direct cost of the Public Offering, resulting in no net effect to the overall stockholders’ equity.

The fair value of the shares of common stock issued in the Public Offering was determined using the closing price of our common stock immediately preceding the closing date of the Public Offering. 

Private Placement 

On April 23, 2024, we completed a private placement (the “Private Placement”) concurrent with the Public Offering noted above. As part of the Private Placement, we sold (i) approximately 2,250 thousand shares of common stock at a price of $0.91 per share of common stock; (ii) redeemable warrants to purchase up to approximately 8,108 thousand shares of our common stock (the “Private Warrants”) at a price of $0.01 per accompanying Private Warrant; and (iii) pre-funded warrants to purchase up to approximately 3,156 thousand shares of common stock (the “Private Pre-Funded Warrants”) at a price of $0.9099 per accompanying Private Pre-Funded Warrant. After deducting customary professional service fees, the net proceeds from the Private Placement amounted to approximately $4,468 thousand. 

The Private Warrants have the same terms as the Public Warrants noted above, except that they are only exercisable six months after their issuance.  

Each Private Pre-Funded Warrant has an exercise price of $0.0001 per share and expire when exercised in full. In accordance with the terms of the Private Pre-Funded Warrants, the Company is prohibited from effecting an exercise of any Private Pre-Funded Warrants to the extent that such exercise would result in the number of shares of common stock beneficially owned by the holder and its affiliates exceeding 4.99% (or 9.99% at election of the holder) of the total number of shares of common stock outstanding immediately after giving effect to the exercise, which percentage may be increased or decreased at the holder’s election not to exceed 9.99%. 

In connection with the Private Placement, we issued approximately 432 thousand warrants to Public Ventures, as compensation for their services as our exclusive placement agent in the Private Placement (the “Placement Agent Warrants”). The terms of the Placement Agent Warrants are the same as the Underwriter Warrants noted above.  

The shares of common stock, Private Pre-Funded Warrants and Private Warrants issued in the Private Placement have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

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(in thousands)		Allocated Amount
Common Stock	$	865
Private Pre-Funded Warrants		1,214
Private Warrants		2,389
	$	4,468

In determining the fair values of the Private Warrants, Private Pre-Funded Warrants, and Placement Agent Warrants, we used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

The Placement Agent Warrants issued in the Private Placement have been accounted for as a direct cost of the Private Placement resulting in no net effect to the overall stockholders’ equity.

The fair value of the shares of common stock issued in the Private Placement was determined using the closing price of our common stock immediately preceding the closing date of the Private Placement. 

Participation Right Exercise 

On June 24, 2024, in connection with the Public Offering and concurrent Private Placement noted above, clirSPV exercised its Participation Right (the “Participation Right Exercise”) and purchased (i) 3,350 thousand shares of our common stock at a price of $0.91 per share; (ii) redeemable warrants to purchase up to approximately 7,040 thousand shares of our common stock (the “Participation Right Warrants,” and together with the Public Warrants, Private Warrants, Underwriter Warrants, Placement Agent Warrants, the “Warrants”) at a price of $0.01 per accompanying Participation Right Warrant; and (iii) pre-funded warrants to purchase up to approximately 1,343 thousand shares of common stock (the “Participation Right Pre-Funded Warrants,” and together with the Private Pre-Funded Warrants, the “Pre-Funded Warrants”) at a price of $0.9099 per accompanying Participation Right Pre-Funded Warrant. After deducting customary professional service fees, the net proceeds from the Participation Right Exercise amounted to approximately $4,277 thousand.

The Participation Right Warrants have the same terms as the Private Warrants noted above. 

The Participation Right Pre-Funded Warrants have the same terms as the Private Pre-Funded Warrants noted above, except that, in accordance with the terms of the Participation Right Pre-Funded Warrants, the Company is prohibited from effecting an exercise that would result in beneficial ownership exceeding 19.99%.  

The shares of common stock, Participation Right Pre-Funded Warrants, and Participation Right Warrants issued in the Participation Right have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

(in thousands)		Allocated Amount
Common Stock	$	1,447
Participation Right Pre-Funded Warrants		580
Participation Right Private Warrants		2,250
	$	4,277

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In determining the fair values of the Participation Right Warrants and Participation Right Pre-Funded Warrants, the Company used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.65
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.25%
Expected dividend yield		0%

The fair value of the shares of common stock issued in connection with the Participation Right Exercise was determined using the closing price of the Company’s common stock immediately preceding the closing date of the Participation Right Exercise. 

Warrants & Pre-Funded Warrants 

The following table summarizes the Warrants (as defined above) and Pre-Funded Warrants (as defined above) activity and outstanding balance as of September 30, 2024, along with the associated weighted average exercise price and weighted average remaining life.  

	Warrants				Pre-Funded Warrants(1)
(in thousands, except per share data)	Number		Wtd. Avg. Exercise Price	Wtd. Avg. Remaining Life (in years)	Number		Wtd. Avg. Exercise Price
Beginning Balance	—		—	—	—		—
Granted	21,319	$	1.0535	4.99	4,499	$	0.0001
Exercised	—		—	—	—		—
Forfeited/Expired	—		—	—	—		—
Outstanding at Period End	21,319	$	1.0535	4.99	4,499	$	0.0001
(1) Pre-Funded warrants have no expiration date and only expire when exercised in full.

Equity Incentive Plan

On June 17, 2021, the Company's shareholders approved and the Company adopted the ClearSign Technologies Corporation 2021 Equity Incentive Plan (the “2021 Plan”) which permits the Company to grant incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance units, and performance shares, to eligible participants, which includes employees, directors and consultants. The Board’s Human Capital and Compensation Committee (the “Compensation Committee”) is authorized to administer the 2021 Plan.

The 2021 Plan provides for an annual increase in available shares equal to the lesser of (i) 10% of the aggregate number of shares of common stock issued by the Company in the prior fiscal year; or (ii) such number provided by the Compensation Committee; provided, however, that the total cumulative increase in the number of shares available for issuance pursuant to this automatic share increase shall not exceed 400 thousand shares of common stock. In 2024, the Board did not exercise their right to limit the automatic increase. Accordingly, the 2021 Plan share reserve increased by 66 thousand shares.

Ending balances for the 2021 Plan is as follows:

	September 30,	December 31,
(in thousands)	2024	2023
Outstanding options and restricted stock units	3,425	3,430
Reserved but unissued shares under the Plan	1,776	2,302
Total authorized shares under the Plan	5,201	5,732

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Stock Options

Under the terms of the 2021 Plan, incentive stock options and nonstatutory stock options must have an exercise price at or above the fair market value on the date of the grant. At the time of grant, the Company will determine the period within which the option may be exercised and will specify any conditions that must be satisfied before the option vests and may be exercised. The Company estimates the fair value of stock options on the date of grant using the Black-Scholes option pricing model.

As permitted by SEC Staff Accounting Bulletin (“SAB”) 107, management utilized the simplified approach to estimate the expected term of the options, which represents the period of time that options granted are expected to be outstanding. Expected volatility has been determined through the Company’s historical stock price volatility. The Company has not made an estimate of forfeitures at the time of the grant, but rather accounts for forfeitures at the time they occur. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield in effect at the time of grant. The Company has never declared or paid dividends and has no plans to do so in the foreseeable future.

Equity Incentive Plan Options

Compensation expense associated with stock option awards for the three and nine months ended September 30, 2024 totaled $37 thousand and $87 thousand, respectively. Compensation expense associated with stock option awards for the three and nine months ended September 30, 2023 totaled $42 thousand and $132 thousand, respectively.

A summary of the Company’s 2011 Equity Incentive Plan and the 2021 Plan stock option activity and changes is as follows:

	September 30,
	2024
(in thousands, except per share data)	Options to Purchase Common Stock	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Outstanding at beginning of year	2,759	$	2.07	5.38
Granted	—	$	—	—
Exercised	—	$	—	—
Forfeited/Expired	(102)	$	0.88	—
Outstanding at end of period	2,657	$	2.11	4.83
Exercisable at end of period	1,947	$	1.75	4.40

The estimated aggregate pretax intrinsic value of the Company’s outstanding vested stock options at September 30, 2024 is $21 thousand. The intrinsic value is the difference between the Company’s common stock price and the option exercise prices multiplied by the number of in-the-money options. This amount changes based on the fair value of the Company’s common stock.

At September 30, 2024, there was $315 thousand of total unrecognized compensation cost related to non-vested stock option-based compensation arrangements. Vesting criteria ranges from time-based to performance-based. The Company records costs for time-based arrangements ratably across the timeframe, whereas performance-based arrangements require management to continually evaluate predetermined goals against actual circumstances.

Inducement Options

During the year ended December 31, 2023, the Company granted non-qualified stock options to its Chief Technology Officer to purchase an aggregate of 150 thousand shares of common stock with an exercise price of $0.91 as a material inducement to accept employment with the Company. These inducement options vest in three equal installments, with one third of the option vesting on the grant date, and each remaining third vesting on the second and third anniversaries

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of the grant date, subject to continued employment with the Company. The fair value of these options were estimated on the grant date using the Black-Scholes valuation model, and totaled $112 thousand. The compensation expense recognized for these awards for the three and nine months ended September 30, 2024, was $9 thousand and $28 thousand, respectively. During the three and nine months ended September 30, 2023, compensation expense for these options was zero.

During the nine months ended September 30, 2023, the Company granted non-qualified stock options to its Director of Customer Relationships and Business Development to purchase an aggregate of 150 thousand shares of common stock with an exercise price of $1.31 as a material inducement to accept employment with the Company. These inducement options vest in three equal installments, with one third of the option vesting on the grant date, and each remaining third vesting on the second and third anniversaries of the grant date, subject to continued employment with the Company. The fair value of these options were estimated on the grant date using the Black-Scholes valuation model, which resulted in $160 thousand. The compensation expense recognized for these awards for the three and nine months ended September 30, 2023 was $62 thousand. During the three months ended December 30, 2023, two-thirds of these inducement options were forfeited upon the departure of the Director of Customer Relationships and Business Development.

These inducement options were granted outside of the 2021 Plan and in accordance with the employment inducement

exemption provided under Nasdaq Listing Rule 5635(c)(4).

Restricted Stock Units

The Company awards employees and directors restricted stock units (“RSUs”) in lieu of cash payment for compensation. These awards are granted from the 2021 Plan. Employee vesting criteria is time based, and compensation expense is recognized ratably across the timeframe. The Company pays payroll withholding taxes on behalf of the employee at vesting, and withholds shares from the employee’s award to cover the taxes payable. The Company accrued taxes for RSU share-based compensation of $38 thousand and $15 thousand for the nine months ended September 30, 2024 and 2023, respectively.

Director vesting criteria is contingent upon the occurrence of one of four future events, which the Company cannot predict or control. Therefore, compensation expense for director RSUs is not recognized until one of these four future events occur, which is in accordance with FASB ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”). Total unrecognized compensation expense for director services as of September 30, 2024 was $501 thousand. Director compensation is earned on a quarterly basis with the target value of compensation set at $79 thousand per quarter, assuming four directors; one lead independent director; one chair for each committee; and two committee members for each of the three committees.

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A summary of the Company’s RSUs activity is as follows:

	September 30,
	2024
(in thousands, except per share data)	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested at beginning of period	671	$	1.05
Granted	420	$	1.00
Vested	(323)	$	1.08
Forfeited	—	$	—
Nonvested at end of period	768	$	1.01

A summary of the Company’s RSU compensation expense is as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024			2023
Compensation Expense	$	27	$	15	$	369	$	225
Weighted Average Value Per Share	$	0.93	$	0.80	$	1.29	$	0.80

Stock Awards

The Company awards employees stock in lieu of cash payment for compensation, typically to satisfy accrued bonus compensation. The awards are granted from the 2021 Plan.

	For the Nine Months Ended
	September 30,
(in thousands, except per share data)	2024		2023
Fair value	$	326	$	234
Weighted Average Value Per Share	$	1.06	$	0.79

For the three months ended for September 30, 2024 and 2023, the Company issued zero stock awards respectively.

Consultant Stock Plan

The 2013 Consultant Stock Plan (the “Consultant Plan”) provides for the granting of shares of common stock to consultants who provide services related to capital raising, investor relations, and making a market in or promoting the Company’s securities. The Company’s officers, employees, and Board members are not entitled to receive grants from the Consultant Plan. The Compensation Committee is authorized to administer the Consultant Plan and establish the grant terms. The Consultant Plan provides for quarterly increases in the available number of authorized shares equal to the lesser of 1% of any new shares issued by the Company during the quarter immediately prior to the adjustment date or such lesser amount as the Board shall determine.

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The Consultant Plan activity is as follows:

	September 30,
(in thousands)	2024
Reserved but unissued shares at beginning of period		188
Increases in the number of authorized shares		115
Grants		(36)
Reserved but unissued shares at end of period		267

The Consultant Plan compensation expense is summarized as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024		2023
Compensation Expense	$	20	$	2	$	26	$	7
Weighted Average Value Per Share	$	0.72	$	0.66	$	0.74	$	0.66

Note 8 – Net Loss per Common Share

The Company calculates net loss per common share in accordance with ASC 260 “Earnings Per Share” (“ASC 260”). Basic and diluted net loss per common share was determined by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Under ASC 260, shares issuable for little or no cash consideration are considered outstanding common shares and included in the computation of basic net loss per share. As such, for the three and nine months ended September 30, 2024, the Company included Pre-Funded Warrants to purchase shares of common stock in its computation of net loss per share. The Pre-Funded Warrants were issued in April and June 2024 with an exercise price of $0.0001 (See "Note 7 - Equity" for additional information).

The following potentially dilutive securities have not been included in the computation of diluted net loss per share for the three and nine months ended September 30, 2024 and 2023, as the result would be anti-dilutive:

	September 30,	September 30,
(in thousands)	2024	2023
Stock Options	3,148	3,250
Restricted Stock Units	768	708
Warrants	21,319	-
Total shares excluded from calculation	25,235	3,958

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Note 9 – Commitments and Contingencies

Litigation

From time to time the Company may become involved in various lawsuits and legal proceedings which arise in the ordinary course of business. Litigation is subject to inherent uncertainties and an adverse result in any such matter may harm the Company’s business. As of the date of this report, the Company is not a party to any material pending legal proceedings or claims that the Company believes will have a material adverse effect on the business, financial condition or operating results.

Indemnification Agreements

The Company maintains indemnification agreements with our directors and officers that may require the Company to indemnify these individuals against liabilities that arise by reason of their status or service as directors or officers, except as prohibited by law.

Note 10 – Government Assistance

During 2022, the Company was awarded a research grant from the Department of Energy (“DOE”) for approximately $250 thousand with the completion of such grant occurring in March 2023. The purpose of the grant was to produce a research paper for a flexible fuel ultra-low NOx process burner capable of burning 100% hydrogen fuel. During 2023, the Company was awarded a Phase 2 grant from the DOE to continue developing this ultra-low NOx hydrogen burner. The Phase 2 grant amount totaled approximately $1.6 million over a two-year period. These awards allow the Company to request reimbursements for expenditures such as labor, material, and administrative costs. During the three and nine months ended September 30, 2024, the Company recognized $116 thousand and $332 thousand in reimbursements from the DOE, respectively. During the three and nine months ended September 30, 2023, the Company recognized $26 thousand and $95 thousand in reimbursements from the DOE, respectively.

Beginning in 2021, the Company received funds relating to the Oklahoma 21^st Century Quality Jobs Act. The estimated duration of the program is up to 10 years and is designed to attract growth industries to Oklahoma. By reporting quarterly salary statistics and meeting agreed upon employment thresholds, the state remits benefit monies to the Company. During three and nine months ended September 30, 2024, the Company recognized $17 thousand and $64 thousand in government assistance from this program, respectively. During three and nine months ended September 30, 2023, the Company recognized $12 thousand and $51 thousand in government assistance from this program, respectively.

Note 11 – Subsequent Events

The Company has evaluated subsequent events as of the date of this report and has none to report.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS AND OTHER INFORMATION CONTAINED IN THIS REPORT

This Quarterly Report on Form 10-Q (this “Form 10-Q” or “report”) contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and the provisions of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Forward-looking statements give our current expectations or forecasts of future events. You can identify these statements by the fact that they do not relate strictly to historical or current facts. You can find many (but not all) of these statements by looking for words such as “approximates,” “believes,” “hopes,” “expects,” “anticipates,” “estimates,” “projects,” “intends,” “plans,” “would,” “should,” “could,” “may,” “will” or other similar expressions in this report. In particular, these include statements relating to future actions; prospective products, applications, customers, and technologies; future performance or results of any products; anticipated expenses; and future financial results. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially from our historical experience and our present expectations or projections. Factors that could cause actual results to differ materially from those discussed in the forward-looking statements include, but are not limited to:

● our limited cash, history of losses, and our expectation that we will continue to experience operating losses and negative cash flows in the near future;

● our ability to successfully develop and implement our technologies and achieve profitability;

● our limited operating history;

● our ability to maintain the listing of our common stock on the Nasdaq Capital Market (“Nasdaq”);

● changes in government regulations that could substantially reduce, or even eliminate, the need for our technology;

● emerging competition and rapidly advancing technology in our industry that may outpace our technology;

● customer demand for the products and services we develop;

● the impact of competitive or alternative products, technologies, and pricing;

● our ability to manufacture any products we design;

● general economic conditions and events and the impact they may have on us and our potential customers;

● our doing business in China and related risks with respect to intellectual property protection, currency exchange, contract enforcement, and rules on foreign investment;

● the impact of a cybersecurity incident or other technology disruption;

● our ability to protect our intellectual property;

● our ability to obtain adequate financing in the future;

● our ability to retain and hire personnel with the experience and talent to develop our products and business;

● our success at managing the risks involved in the foregoing items; and

● other factors discussed in this report and in the section titled “Risk Factors” in our most recent Annual Report on Form 10-K.

Forward-looking statements may appear throughout this report, including, without limitation, Item 2 “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” The forward-looking statements are based upon management’s beliefs and assumptions and are made as of the date of this report. We undertake no obligation to publicly update or revise any forward-looking statements included in this report. You should not place undue reliance on these forward-looking statements.

Unless otherwise stated or the context otherwise requires, the terms “ClearSign,” “we,” “us,” “our” and the “Company” refer to ClearSign Technologies Corporation and its subsidiary, ClearSign Asia Limited.

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ITEM 2.MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with the unaudited consolidated condensed financial statements and related notes included elsewhere in this Form 10-Q as well as our audited consolidated financial statements and related notes included in our most recent Annual Report on Form 10-K. In addition to historical information, this discussion and analysis here and throughout this Form 10-Q contains forward-looking statements that involve risks, uncertainties, and assumptions. Our actual results may differ materially from those anticipated in these forward-looking statements due to a number of factors, including but not limited to, the risks described in the section titled “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023.

Overview

We design and develop technologies for the purpose of decarbonization and improving key performance characteristics of combustion systems, including emission and operational performance, energy efficiency and overall cost-effectiveness. Our ClearSign Core™ technology has been proven in full scale industrial test furnaces and boilers and first customer installations are currently operating in normal commercial applications. We have generated nominal revenues from operations to date to meet operating expenses.

We have incurred losses since inception totaling $98.0 million and we expect to experience operating losses and negative cash flow for the foreseeable future. We have historically financed our operations primarily through issuances of equity securities. As of September 30, 2024, we have raised approximately $105.2 million in gross proceeds through the sale of our equity securities. We may need to raise additional capital in the future, however, the significant volatility in the capital markets may negatively affect our ability to raise this additional capital.

In order to generate meaningful revenues, our technologies must gain market recognition and acceptance to develop sufficient recurring sales. In addition, management believes that the successful growth and operation of our business is dependent upon our ability to obtain adequate sources of funding through co-development agreements, strategic partnering agreements, or equity or debt financing to support commercialization of our research and development efforts, protect intellectual property, form relationships with strategic partners and provide for working capital and general corporate purposes. There can be no assurance that we will be successful in achieving our long term plans, or that such plans, if consummated, will result in profitable operations or enable us to continue in the long term as a going concern.

Our costs include employee salaries and benefits, compensation paid to consultants, materials and supplies for prototype development and manufacture, costs associated with development activities including materials, sub-contractors, travel and administration, legal and accounting expenses, sales and marketing costs, general and administrative expenses, and other costs associated with an early stage, publicly traded technology company. We currently have 16 full-time employees. Because using third party expertise and resources is more efficient than maintaining full time resources, we also expect to incur ongoing consulting expenses related to technology development and some administrative, sales and legal functions commensurate with our current level of activities.

The amount that we spend for any specific purpose may vary significantly, and could depend on a number of factors including, but not limited to, the pace of progress of our commercialization and development efforts, actual needs with respect to product testing, development and research, market conditions, and changes in or revisions to our sales and marketing strategies.

Research, development, and commercial acceptance of new technologies are, by their nature, unpredictable.  Although we undertake development and commercialization efforts with reasonable diligence, there can be no assurance that the net proceeds from our securities offerings will be sufficient to enable us to develop our technology to the extent needed to create sufficient future sales to sustain operations.  If the net proceeds from these offerings are insufficient for this purpose, we will consider other options to continue our path to commercialization,

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including, but not limited to, additional financing through follow-on equity offerings, debt financing, co-development agreements, sale or licensing of developed intellectual or other property, or other alternatives.

We cannot assure that our technologies will be accepted, that we will ever earn revenues sufficient to support our operations, or that we will ever be profitable. Furthermore, we have no committed source of financing, and we cannot assure that we will be able to raise money as and when we need it to continue our operations. If we cannot raise funds as and when we need them, we may be required to scale back our development by reducing expenditures for employees, consultants, business development and marketing efforts or to otherwise severely curtail, or even to cease, our operations.

Recent Developments

Public Offering and Concurrent Private Placement

On April 23, 2024, we completed an underwritten public offering, whereby we sold 4,620,760 shares of common stock and 5-year redeemable warrants to purchase up to 4,620,760 shares of common stock (the “Public Warrants”) (plus a 45-day option to purchase up to an additional 693,114 shares of common stock and Public Warrants to purchase up to 693,114 shares of common stock, or up to 693,114 shares of common stock only) at a price of $0.92 per set of one share of common stock and one Public Warrant. Concurrently, we completed a private placement, whereby we sold 2,249,763 shares of common stock, pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to 3,155,642 shares of common stock and redeemable warrants (the “Private Warrants”) to purchase up to 8,108,106 shares of common stock. The offering prices in the private placement were $0.91 per share and $0.01 per Private Warrant, or $0.9099 per Pre-Funded Warrant and $0.01 per Private Warrant, as applicable. The redeemable warrants issued in both offerings have an exercise price equal to $1.05 per share.

In connection with this offering, we issued Public Ventures, LLC (“Public Ventures”) 5-year warrants to purchase up to 369,660 shares of common stock at an exercise price of $1.1375 per share as part of their underwriter compensation, which underwriter warrants become exercisable on October 16, 2024 (the “Underwriter Warrants”). We also issued Public Ventures 5-year warrants to purchase up to 432,432 shares of common stock at an exercise price of $1.1375 per share as part of their placement agent compensation in connection with the private placement, which warrants become exercisable on October 16, 2024 (the “Placement Agent Warrants,” and together with the Public Warrants, Private Warrants, Pre-Funded Warrants and Underwriter Warrants, the “Warrants,” and the shares issuable upon exercise of the Warrants, the “Warrant Shares”). Both sets of warrants may be exercised on a cashless basis based on a formula set forth in the respective warrants.

Subsequently, on May 15, 2024, Public Ventures exercised its option in full to purchase an additional 693,114 shares of common stock and Public Warrants to purchase up to 693,114 shares of common stock at a price of $0.92 per set of one share of common stock and one Public Warrant, in connection with which we issued Public Ventures additional Underwriter Warrants to purchase up to 55,449 shares of common stock.

The public offering and the concurrent private placement resulted in combined gross proceeds of approximately $9,300 thousand, and net proceeds of approximately $8,100 thousand. The exercise of Public Ventures’ option to purchase additional shares of common stock and Public Warrants resulted in additional gross proceeds of approximately $638 thousand.

Participation Right Exercise

On June 24, 2024, following clirSPV, LLC’s (the “SPV”) notice to exercise its participation right in connection with the underwritten public offering and concurrent private placement discussed above (See “Note 7 – Equity” for additional information), we entered into a securities purchase agreement (the “Securities Purchase Agreement”) with the SPV whereby we issued an aggregate of (i) 3,907,000 shares of common stock, (ii) Pre-Funded Warrants to purchase up to 786,000 shares of common stock, and (iii) Private Warrants to purchase up to 7,039,500 shares of common stock.

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Subsequently, on June 26, 2024, the SPV and we entered into an Amendment to the Securities Purchase Agreement (the “Amendment”) to provide for a revised allocation of the SPV’s subscription between shares of common stock and Pre-Funded Warrants in lieu thereof. Pursuant to the Amendment, the SPV subscribed for: (i) 3,350,000 shares of common stock, (ii) Pre-Funded Warrants to purchase up to 1,343,000 shares of common stock and (iii) Private Warrants to purchase up to 7,039,500 shares of common stock, for aggregate gross proceeds of approximately $4.3 million.

Nasdaq Deficiency Notice

On May 2, 2024, we received a letter from Nasdaq’s Listing Qualifications Staff (the “Staff”) indicating that, based upon our common stock’s closing bid price for the last 30 consecutive business days beginning on March 20, 2024 and ending on May 1, 2024, we no longer meet the requirement to maintain a minimum bid price of $1 per share, as set forth in Nasdaq Listing Rule 5550(a)(2) (the “Bid Price Rule”). In accordance with Nasdaq rules, we were provided a period of 180 calendar days, or until October 29, 2024, in which to regain compliance with the Bid Price Rule.

On October 30, 2024, we received a second letter from the Staff, granting our request for a 180-day extension to regain compliance with the Bid Price Rule. We now have until April 28, 2025 to regain compliance with the Bid Price Rule. If at any time prior to April 28, 2025, our common stock’s closing bid price is at least $1 per share for a minimum of ten consecutive business days during such 180-day extension, we will regain compliance with the Bid Price Rule. As part of our request for the 180-day extension, we notified Nasdaq that we intend to regain compliance with the Bid Price Rule by effecting a reverse stock split, if necessary. If we do not regain compliance with the Bid Price Rule during the additional 180-day extension, Nasdaq will provide written notification to us that our common stock will be delisted. At that time, the Company may appeal the relevant delisting determination to a hearings panel pursuant to the procedures set forth in the applicable Nasdaq Listing Rules. However, there can be no assurance that, if we do appeal the delisting determination by Nasdaq to the hearings panel, that such appeal would be successful.

This second letter from the Staff does not result in the immediate delisting of our common stock from Nasdaq, and we intend to monitor our common stock’s closing bid price and consider our available options in the event that our common stock’s closing bid price remains below $1 per share.

Amendment to Certificate of Incorporation

On June 25, 2024, we held our 2024 annual meeting of stockholders, at which our stockholders approved, among other items, an increase in the number of authorized shares of common stock available for issuance under our certificate of incorporation (as amended, the “certificate of incorporation”) to 87,500,000 shares from 62,500,000 shares previously authorized.

Accordingly, on June 25, 2024, we filed an amendment to our certificate of incorporation with the Secretary of State of the State of Delaware, reflecting the increase of our authorized shares of common stock to 87,500,000 shares, which became effective upon filing.

Suspension of Activities in China

On October 1, 2024, we informed our employees that we were suspending our operations in China as a result of delayed progress on commercialization of its products in that geographic market and as part of our efforts to align strategic priorities and to reduce operating costs. The suspension of our operations in China will involve declaring our Beijing, China wholly-owned subsidiary dormant, which is a legal entity status available under current China law. Under this legal entity status, operational activities cease for a time period not to exceed three years. By pursuing this entity status, we will initiate a project to suspend current operational activities, which are estimated to cease on or before December 31, 2024. Suspension activities include disposal and shipment of certain equipment in China, the termination of 2 employees and related benefit costs, and legal entity filing fees. In connection with this action, we estimate that we will incur certain one-time costs, primarily consisting of employee termination payments, as well as equipment disposal

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and shipment and legal filing fees. See “Note 2 – Summary of Significant Accounting Policies – Foreign Operations” above for additional information.

Critical Accounting Policies

The following discussion and analysis of financial condition and results of operations is based upon our condensed consolidated financial statements, which have been prepared in conformity with accounting principles generally accepted in the United States. Certain accounting policies and estimates are particularly important to the understanding of our financial position and results of operations. These policies and estimates require the application of significant judgment by management. These estimates can be materially affected by changes from period to period as economic factors and conditions outside of our control change. As a result, they are subject to an inherent degree of uncertainty. In applying these policies, our management uses their judgment to determine the appropriate assumptions to be used in the determination of certain estimates. Those estimates are based on our historical operations, our future business plans and projected financial results, the terms of existing contracts, our observance of trends in the industry, information provided by our customers and information available from other outside sources, as appropriate. We believe the current assumptions and other considerations used to estimate amounts reflected in the condensed consolidated financial statements included in this Form 10-Q are appropriate.

This Form 10-Q and our most recent Annual Report on Form 10-K include discussions of our accounting policies, as well as methods and estimates used in the preparation of our audited consolidated financial statements. For further information on our critical accounting policies and estimates, see “Item 7 – Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our most recent Annual Report on Form 10-K, the notes to our audited consolidated financial statements included in our most recent Annual Report on Form 10-K and “Note 2 – Summary of Significant Accounting Policies” of our unaudited condensed consolidated financial statements included elsewhere in this Form 10-Q. Since our most recent Annual Report on Form 10-K, we have not experienced a material change to our critical accounting policies or the methods and applications used to develop our accounting estimates.

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RESULTS OF OPERATIONS

Comparison of the Three and Nine Months Ended September 30, 2024 and 2023

Highlights of our quarter financial performance are as follows:

	For the Three Months Ended
(in thousands, except per share data)	September 30,
	2024		2023		$ Change		% Change
Revenues	$	1,859	$	85	$	1,774	NM
Cost of goods sold		1,308		61	$	1,247	NM
Gross profit		551		24	$	527	NM
Research and development		329		93	$	236	253.8	%
General and administrative		1,655		1,428	$	227	15.9	%
Operating Expenses		1,984		1,521	$	463	30.4	%
Other income, net		278		165	$	113	68.5	%
Net loss	$	(1,155)	$	(1,332)	$	177	13.3	%
Basic and diluted net income per common share	$	(0.02)	$	(0.03)	$	0.01	33.3	%
NM = Not meaningful

	For the Nine Months Ended
(in thousands, except per share data)	September 30,
	2024		2023		$ Change		% Change
Revenues	$	3,006	$	1,129	$	1,877	166.3	%
Cost of goods sold		1,976		870	$	1,106	127.1	%
Gross profit		1,030		259	$	771	297.7	%
Research and development		1,012		440	$	572	130.0	%
General and administrative		4,840		4,649	$	191	4.1	%
Operating Expenses		5,852		5,089	$	763	15.0	%
Other income, net		687		591	$	96	16.2	%
Net loss	$	(4,135)	$	(4,239)	$	104	2.5	%
Basic and diluted net income per common share	$	(0.09)	$	(0.11)	$	0.02	18.2	%

Revenues and Gross Profit

Consolidated revenues for the three months ended September 30, 2024 were $1,859 thousand compared to $85 thousand for the same period in 2023. Revenues for the three months ended September 30, 2024 were predominantly generated from our process burner product line by shipping multiple burners to a California refinery customer. Revenues for the three months ended September 30, 2023 were generated from a boiler burner order. Consolidated revenues for the nine months ended September 30, 2024 were $3,006 thousand compared to $1,129 thousand for the same period in 2023. Revenues for the nine months ended September 30, 2024 were predominantly generated from our process burner line by shipping multiple burners, performing engineering feasibility studies, and delivering spare parts, all of which constitute contractual performance obligations under ASC 606. Revenues for the nine months ended September 30, 2023 were generated predominantly from a burner performance test, engineering feasibility study, spare parts orders, and a boiler burner sale.

Gross profit increased by $527 thousand and $771 thousand, or 297.7%, for the three and nine months ended September 30, 2024, respectively, compared to the same time periods in 2023. The favorable increase in gross profit for the three months ended September 30, 2024 was predominantly due to higher revenues, as described above. The favorable increase in gross profit for the nine months ended September 30, 2024 was due to higher revenues and an increased profit margin, which increased by 11.3% and added an additional $340 thousand in profit compared to the same period in 2023. This favorable change in profit margin was predominantly driven by the shipment of our process

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burners during the nine months ended September 30, 2024, which was expected since the comparable period in 2023 included a low margin burner performance test.

Operating Expenses

Operating expenses consist of research and development (“R&D”) and general and administrative (“G&A”) expenses. These are addressed separately below.

Research and Development

R&D expenses increased $236 thousand, or 253.8%, and $572 thousand, or 130.0%, for the three and nine months ended September 30, 2024, respectively, compared to the same time periods in 2023. This unfavorable year-over-year increase in R&D expenses was mainly driven by additional head count and related benefit costs of $69 thousand and $225 thousand for the three and nine months ended September 30, 2024, respectively, that did not exist in the comparable periods in 2023. In addition, we incurred an unfavorable additional year-over-year expense related to product development costs for our process burner product line for a total of $91 thousand and $234 thousand for the three and nine months ended September 30, 2024, respectively.

General and Administrative

G&A expenses increased by $227 thousand, or 15.9%, for the three months ended September 30, 2024, compared to the same time period in 2023. This unfavorable increase in G&A expenses is primarily attributed to a one-time non-recurring accrual estimate of $394 thousand related to the decision to suspend our China operations. These G&A expenses related to the suspension of our operations in China include severance and related benefit costs, the disposal and shipment of certain equipment in China, and legal entity filing fees. See “Note 2 – Summary of Significant Accounting Policies – Foreign Operations” and “Recent Developments – Suspension of Activities in China” above for additional information. This unfavorable increase in G&A expenses was partially offset by a decrease of $93 thousand in human capital and benefit costs primarily driven by the timing of employee departures and subsequent onboarding costs.

G&A expenses for the nine months ended September 30, 2024, increased by $191 thousand, or 4.1%, compared to the same period in 2023. This unfavorable increase in G&A expenses is primarily attributed to a one-time non-recurring accrual estimate of $394 thousand related to our decision to suspend our operations in China, as described above. The year-over-year increase in G&A expenses was partially offset by a decrease of $228 thousand in human capital and benefit costs, which was primarily driven by the timing of employee departures and subsequent onboarding costs.

Other Income, net

Other income, net increased by $113 thousand, or 68.5%, for the three months ended September 30, 2024, compared to the same period in 2023. The favorable increase is primarily due to $89 thousand increase in government assistance from our Department of Energy hydrogen burner development grant, and $61 thousand increase in interest income due to a higher cash balance during the nine months ended September 30, 2024, compared to the same period in 2023. The increase was partially offset by a decrease of $43 thousand in income from the sale of materials from the decommissioning of our Seattle office during the comparable period in 2023.

Other income, net increased $96 thousand, or 16.2%, for the nine months ended September 30, 2024, compared to the same period in 2023. This favorable increase was predominantly due to the $237 thousand increase in government assistance related to our Department of Energy hydrogen burner project. This year-over-year increase was partially offset by a $154 thousand decrease in income in connection with the decommissioning of our Seattle office during 2023, while we derived no income from this project during the comparable period in 2024.

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Liquidity and Capital Resources

At September 30, 2024, our cash and cash equivalent balance totaled $14,486 thousand compared to $5,684 thousand at December 31, 2023, an increase of $8,802 thousand. The increase in cash and cash equivalent balance is primarily attributable to our public offering, concurrent private placement and the related SPV’s exercise of its participation right. See “Note 7 – Equity” for additional information.

At September 30, 2024, we had working capital of $13,851 thousand compared to $4,253 thousand at December 31, 2023. Our Annual Report on Form 10-K filed with the SEC on April 1, 2024, contained a “going concern” note, which raised substantial doubt about our ability to continue as a going concern. We believe that we have alleviated the substantial doubt following the consummation of the recent public offering, concurrent private placement and the related SPV’s exercise of its participation right. See “Note 7 – Equity” for additional information. Accordingly, we believe we have sufficient cash and expected cash collections to fund current operating expenses for over twelve months. We have no contractual debt obligations and to the extent we may require additional funds beyond twelve months from the date hereof, and customer cash collections cannot fund our needs, we may utilize equity offerings. Historically, we have funded operations predominantly through equity offerings. Until the growth of revenue increases to a level that covers operating expenses, the Company intends to continue to fund operations in this manner, although the volatility in the capital markets may negatively affect our ability to do so. As of September 30, 2024, approximately 21.3 million shares of our common stock are issuable upon exercise of the Warrants (as defined above), and we may receive up to $22.5 million in aggregate gross proceeds from the cash exercises thereof, subject to certain beneficial ownership limitations set forth therein. The Warrants require the warrant holder to tender cash upon exercise, with the exception of the Underwriter Warrants which allow the holder to exercise cashless if they so desire. These equity financial instruments may from time-to-time fund future cash needs, but the volatility of our stock and the risk tolerance of warrant holders will play a key role in this type of funding.

Operating activities for the nine months ended September 30, 2024, resulted in cash outflows of $3,958 thousand, primarily due to the net loss of $4,135 thousand during such period, which was partially offset by a non-cash expense of $688 thousand. The decision to suspend our China operations increased accounts payable and accrued liabilities by $394 thousand during the three months ended September 30, 2024, which represents a one-time accrual estimate for the costs to prepare and place our Beijing China entity into a dormant state. See “Note 2 – Summary of Significant Accounting Policies – Foreign Operations” and “Recent Developments – Suspension of Activities in China” above for additional information. The change in contract liabilities during the nine months ended September 30, 2024 was predominantly impacted by our shipment of process burners during the three months ended September 30, 2024. See “Note 5 – Revenue, Contract Assets and Contract Liabilities” above for additional information.

Operating activities for the nine months ended September 30, 2023, resulted in cash outflows of $1,783 thousand, primarily due to the loss for the period of $4,239 thousand, offset with non-cash expenses of $678 thousand, and an increase of $1,554 thousand of contract liabilities, which represents payments from customers in advance of future project costs.

Investing activities for the nine months ended September 30, 2024, resulted in cash outflows of $177 thousand, which is primarily attributable to $159 thousand of disbursements for patents and other intangible assets.

Investing activities for the nine months ended September 30, 2023, resulted in cash inflows of $2,595 thousand, which is primarily attributable to the redemption $4,847 thousand of short-term held-to-maturity U.S. treasuries, partially offset by $2,162 thousand in purchases of the same type of investments.

Financing activities for the nine months ended September 30, 2024, resulted in cash inflows of $12,936 thousand, which is primarily attributable to the net proceeds received of $12,967 thousand from the issuance of securities in connection with the recent equity offerings (see “Note 7 – Equity” above for additional information).

Financing activities for the nine months ended September 30, 2023, resulted in cash outflows of $15 thousand due to disbursements for taxes paid related to vesting of employee restricted stock units.

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Off-Balance Sheet Transactions

We do not have any off-balance sheet transactions.

ITEM 3.QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

As a smaller reporting company, we are not required to provide this information.

ITEM 4.CONTROLS AND PROCEDURES

Disclosure Controls and Procedures

We maintain disclosure controls and procedures, as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, that are designed to reasonably ensure that information required to be disclosed in our reports filed under the Exchange Act, is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms, and that such information is accumulated and communicated to our management, including our principal executive officer and principal accounting and financial officer, as appropriate, to allow timely decisions regarding required disclosure.

We carried out an evaluation under the supervision and with the participation of management, including our Chief Executive Officer (principal executive officer) and our Chief Financial Officer (principal accounting and financial officer), of the effectiveness of the design and operation of our disclosure controls and procedures as of September 30, 2024, the end of the period covered by this Form 10-Q. Based upon the evaluation of our disclosure controls and procedures as of September 30, 2024, our Chief Executive Officer (principal executive officer) and our Chief Financial Officer (principal accounting and financial officer) concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control over Financial Reporting

There have been no changes in our internal control over financial reporting that occurred during the quarter ended September 30, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Limitations on Effectiveness of Controls and Procedures

Our management, including our Chief Executive Officer (principal executive officer) and our Chief Financial Officer (principal accounting and financial officer), does not expect that our disclosure controls and procedures or our internal control over financial reporting will prevent or detect all errors and all fraud. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, have been detected. These inherent limitations include the realities that judgments in decision making can be faulty, and that breakdowns can occur because of a simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by management override of the controls. The design of any system of controls is also based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions. Over time, controls may become inadequate because of changes in conditions, or the degree of compliance with policies or procedures. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected.

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PART II - OTHER INFORMATION

ITEM 1.LEGAL PROCEEDINGS

From time to time, we may become involved in various lawsuits and legal proceedings which arise in the ordinary course of business. However, litigation is subject to inherent uncertainties and an adverse result in these or other matters may arise from time to time that may harm our business. We are currently not aware of any such legal proceedings or claims that we believe will have a material adverse effect on our business, financial condition or operating results.

ITEM 1A.RISK FACTORS

We incorporate herein by reference the risk factors included under “Part I - Item 1A. Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2023 which we filed with the SEC on April 1, 2024. There are no material changes from the risk factors set forth in such prior filing, except as set forth below.

There may be future sales of our common stock, or a perception that these sales could occur, which events could cause the price of our common stock to decline.

Sales of a substantial number of shares of our common stock in the public market or the perception that such sales might occur could materially adversely affect the market price of the shares of our common stock. For instance, the securities issued in our recent equity offerings (see “Note 7 – Equity” for additional information), as well as the Warrant Shares, have been registered for resale and are freely tradable without restriction or further registration under the Securities Act. As a result, a substantial number of shares of common stock may be sold in the public market following such offerings, subject to certain contractual transfer and beneficial ownership restrictions. We cannot predict the effect, if any, that market sales of those shares of common stock or the availability of those shares for sale will have on the market price of our common stock. Further, if there are significantly more shares of common stock offered for sale than buyers are willing to purchase, then the market price of the common stock may decline to a market price at which buyers are willing to purchase the offered common stock and sellers remain willing to sell common stock.

We will have broad discretion as to the proceeds that we receive from the cash exercise by any holder of the Warrants, and we may not use the proceeds effectively.

We may receive up to approximately $22.5 million in aggregate gross proceeds from cash exercises of the Warrants, based on the per share exercise price of the Warrants, and to the extent that we receive such proceeds, we intend to use the net proceeds from cash exercises of the Warrants for working capital, research and development, marketing and sales, and general corporate purposes. We have considerable discretion in the application of such proceeds. You must rely on our judgment regarding the application of the net proceeds from cash exercises of the Warrants, which may be used for corporate purposes that do not improve our profitability or increase the price of our shares of common stock. Such proceeds may also be placed in investments that do not produce income or that lose value. The failure to use such funds by us effectively could have a material adverse effect on our business, financial condition, operating results and cash flow.

You may experience future dilution as a result of issuance of the Warrant Shares, future equity offerings by us and other issuances of our common stock or other securities. In addition, the issuance of the Warrant Shares, to the extent the Warrants are exercisable, and future equity offerings and other issuances of our common stock or other securities may adversely affect our common stock price.

You may experience future dilution as a result of issuance of the Warrant Shares and other issuances of our common stock or other securities. In order to raise additional capital, if needed, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share as prior issuances of common stock. We may not be able to sell shares or other securities in any other offering at a price per share that is equal to or greater than the price per share previously paid by

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investors, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of our common stock or securities convertible into common stock in future transactions may be higher or lower than the prices per share for previous issuances of common stock or securities convertible into common stock paid by certain investors. In addition, the exercise price of the Warrants may be equal to or greater than the price per share previously paid by certain investors. You will incur dilution upon exercise of any outstanding stock options, warrants or upon the issuance of shares of common stock under our equity incentive programs.

If we fail to comply with Nasdaq’s continued minimum closing bid requirements by April 28, 2025 or other requirements for continued listing, including stockholder equity requirements, our common stock may be delisted and the price of our common stock and our ability to access the capital markets could be negatively impacted.

Our common stock is listed for trading on Nasdaq, therefore, we must satisfy Nasdaq’s continued listing requirements, including, among other things, a minimum closing bid price requirement of $1.00 per share for 30 consecutive business days. On May 2, 2024, the Staff notified us that we did not comply with the Bid Price Rule for continued listing, as set forth in Nasdaq Listing Rule 5550(a)(2), during the 30 consecutive business day period beginning on March 20, 2024 and ending on May 1, 2024. We were granted 180 calendar days, or until October 29, 2024, to regain compliance with the Bid Price Rule.

On October 30, 2024, the Staff sent us a second letter granting our request for a 180-day extension, or until April 28, 2025, to regain compliance with the Bid Price Rule. To regain compliance with the Bid Price Rule and to qualify for continued listing on Nasdaq, the minimum bid price per share of our common stock must be at least $1.00 for at least ten consecutive business days during the 180-day extension. As part of our request for the 180-day extension, we notified Nasdaq that we intend to regain compliance with the Bid Price Rule by effecting a reverse stock split, if necessary. If we do not regain compliance with the Bid Price Rule during the 180-day extension, our common stock will be subject to delisting by Nasdaq. At that time, we may appeal the relevant delisting determination to a hearings panel pursuant to the procedures set forth in the applicable Nasdaq Listing Rules. However, there can be no assurance that, if the we do appeal the delisting determination by Nasdaq to the hearings panel, that such appeal would be successful.

There can be no assurance that we will be able to regain compliance with Nasdaq’s listing rules. If we are unable to regain compliance with the Bid Price Rule or if we fail to meet any of the other continued listing requirements, including stockholder equity requirements, our securities may be delisted from Nasdaq, which could reduce the liquidity of our common stock materially and result in a corresponding material reduction in the price of our common stock. In addition, delisting could harm our ability to raise capital on terms acceptable to us, or at all, and may result in the potential loss of confidence by investors, employees and business development opportunities.

ITEM 2.UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

On September 24, 2024, we issued 3.8 thousand shares of common stock at a fair market value price per share of $0.81, the closing price of our common stock as reported on Nasdaq on November 16, 2023, the date of grant, and on August 24, 2024, we issued 25 thousand shares of common stock at a fair market value price per share of $0.7063, from our 2013 Consultant Stock Plan to our investor relations firm, Firm IR Group LLC (“Firm IR”). The 3.8 thousand shares were issued for services provided during the three months ended September 30, 2024. The 25 thousand shares were issued as a one-time discretionary payment for Firm IR’s services provided during our most recent equity offerings (see “Note 7 – Equity” above for additional information). These shares were issued in reliance upon the exemption from registration provided by Section 4(a)(2) of the Securities Act, for a transaction by an issuer not involving a public offering.

ITEM 3.DEFAULTS UPON SENIOR SECURITIES

Not applicable.

31

ITEM 4.MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5.OTHER INFORMATION

None of the Company’s directors or officers adopted, modified or terminated a Rule 10b-5 trading arrangement or a non-Rule 10b-5 trading arrangement during the fiscal quarter ended September 30, 2024, as such terms are defined under Item 408(a) of Regulation S-K.

Disclosure Pursuant to Item 5.02 of Current Report on Form 8-K – Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On November 13, 2024, the Human Capital and Compensation Committee (the “Compensation Committee”) of the Board of Directors (the “Board”) of ClearSign Technologies Corporation (the “Company”) approved (i) an increase to Colin James Deller’s, the Company’s Chief Executive Officer, annual bonus target from up to 60% to up to 80% of his annual base salary; and (ii) an increase to Brent Hinds’, the Company’s Chief Financial Officer, base salary from $200,000 to $220,000, with such increases to be effective as of January 1, 2025. The Board ratified the Compensation Committee’s approval on the same date. Except as described herein, there were no further changes to Dr. Deller’s and Mr. Hinds’ employment agreements.

Item 6. Exhibit	EXHIBITS
Number		Document
3.1**		Certificate of Incorporation of ClearSign Technologies Corporation, a Delaware corporation (incorporated by reference to Exhibit 3.3 of the Company’s Form 8-K filed with the Securities and Exchange Commission on June 15, 2023).
3.2**		Certificate of Amendment, as filed with the Secretary of the State of Delaware on June 25, 2024 (incorporated by reference to Exhibit 3.1 of the Company’s Form 8-K filed with the Securities and Exchange Commission on June 26, 2024).
3.3**		Bylaws of ClearSign Technologies Corporation, a Delaware corporation (incorporated by reference to Exhibit 3.4 of the Company’s Form 8-K filed with the Securities and Exchange Commission on June 15, 2023).
4.1**		Form of Common Warrant (incorporated by reference to Exhibit 4.1 of the Company’s Form 8-K filed with the Securities and Exchange Commission on April 19, 2024).
4.2**		Form of Underwriter’s Warrant (incorporated by reference to Exhibit 4.2 of the Company’s Form 8-K filed with the Securities and Exchange Commission on April 19, 2024).
4.3**		Form of Private Warrant (incorporated by reference to Exhibit 4.3 of the Company’s Form 8-K filed with the Securities and Exchange Commission on April 19, 2024).
4.4**		Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 of the Company’s Form 8-K filed with the Securities and Exchange Commission on April 23, 2024).

32

4.5**	Form of Placement Agent Warrant (incorporated by reference to Exhibit 4.4 of the Company’s Form 8-K filed with the Securities and Exchange Commission on April 19, 2024).
10.1+**	G. Todd Silva’s Offer Letter, effective as of August 1, 2024 (incorporated by reference to Exhibit 10.1 of the Company’s Form 8-K filed with the Securities and Exchange Commission on August 6, 2024).
31.1*	Rule 13a-14(a)/15d-14(a) Certification of Principal Executive Officer.
31.2*	Rule 13a-14(a)/15d-14(a) Certification of Principal Financial Officer.
32.1***	Section 1350 Certification of Principal Executive Officer and Principal Financial Officer.
101.INS*	Inline XBRL Instance Document.
101.SCH*	Inline XBRL Taxonomy Extension Schema Document.
101.CAL*	Inline XBRL Taxonomy Extension Calculation Linkbase Document.
101.DEF*	Inline XBRL Taxonomy Extension Definition Linkbase Document.
101.LAB*	Inline XBRL Taxonomy Extension Label Linkbase Document.
101.PRE*	Inline XBRL Taxonomy Extension Presentation Linkbase Document.
104*	Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101).

*Filed herewith.

**Previously filed.

***Furnished herewith.

+Indicates an agreement with management or compensatory plan or arrangement

33

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

		CLEARSIGN TECHNOLOGIES CORPORATION
Date: November 14, 2024	By:	/s/ Colin James Deller
		Colin James Deller
		Chief Executive Officer
		(Principal Executive Officer)

Date: November 14, 2024	By:	/s/ Brent Hinds
		Brent Hinds
		Chief Financial Officer (Principal Financial and Accounting Officer)

34

EX-31.1

Exhibit 31.1

CERTIFICATION

I, Colin James Deller, certify that:

1. I have reviewed this quarterly report on Form 10-Q of ClearSign Technologies Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15-d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including any consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting;

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: November 14, 2024

/s/ Colin James Deller

Colin James Deller

Chief Executive Officer

(Principal Executive Officer)

EX-31.2

Exhibit 31.2

CERTIFICATION

I, Brent Hinds, certify that:

1. I have reviewed this quarterly report on Form 10-Q of ClearSign Technologies Corporation;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15-d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including any consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting;

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: November 14, 2024

/s/ Brent Hinds

Brent Hinds

Chief Financial Officer

(Principal Financial and Accounting Officer)

EX-32.1

Exhibit 32.1

CERTIFICATION

In connection with the quarterly report on Form 10-Q of ClearSign Technologies Corporation (the “Company”) for the period ended September 30, 2024 as filed with the Securities and Exchange Commission (the “Report”), we, Colin James Deller, Chief Executive Officer (Principal Executive Officer) and Brent Hinds, Chief Financial Officer (Principal Financial and Accounting Officer) of the Company, hereby certify as of the date hereof, solely for purposes of Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and Title 18, Chapter 63, Section 1350 of the United States Code, that to the best of my knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d), as applicable, of the Exchange Act, and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company at the dates and for the periods indicated.

Date: November 14, 2024

/s/ Colin James Deller

Colin James Deller

Chief Executive Officer

(Principal Executive Officer)

/s/ Brent Hinds

Brent Hinds

Chief Financial Officer

(Principal Financial and Accounting Officer)

This certification accompanies the Form 10-Q to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act (whether made before or after the date of the Report), irrespective of any general incorporation language contained in such filing.

XML

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2024	Nov. 06, 2024
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-35521
Entity Registrant Name	CLEARSIGN TECHNOLOGIES CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2056298
Entity Address, Address Line One	8023 E. 63rd Place, Suite 101
Entity Address, City or Town	Tulsa
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	74133
City Area Code	918
Local Phone Number	236-6461
Title of 12(b) Security	Common Stock
Trading Symbol	CLIR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		50,234,407
Entity Interactive Data Current	Yes
Entity Central Index Key	0001434524
Document Fiscal Year Focus	2024
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Amendment Flag	false

XML

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 14,486	$ 5,684
Accounts receivable	749	287
Contract assets	149	188
Prepaid expenses and other assets	610	350
Total current assets	15,994	6,509
Fixed assets, net	245	275
Patents and other intangible assets, net	855	836
Total Assets	17,094	7,620
Current Liabilities:
Accounts payable and accrued liabilities	1,486	366
Current portion of lease liabilities	82	71
Accrued compensation and related taxes	401	703
Contract liabilities	174	1,116
Total current liabilities	2,143	2,256
Long Term Liabilities:
Long term lease liabilities	128	172
Total liabilities	2,271	2,428
Commitments and contingencies (Note 9)
Stockholders' Equity:
Preferred stock, $0.0001 par value, zero shares issued and outstanding
Common stock, $0.0001 par value, 50,234,407 and 38,687,061 shares issued and outstanding at September 30, 2024 and December 31, 2023, respectively	5	4
Additional paid-in capital	112,686	98,922
Accumulated other comprehensive loss	(16)	(17)
Accumulated deficit	(97,852)	(93,717)
Total equity	14,823	5,192
Total Liabilities and Equity	$ 17,094	$ 7,620

XML

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares issued	50,234,407	38,687,061
Common stock, shares outstanding	50,234,407	38,687,061

XML

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenues	$ 1,859	$ 85	$ 3,006	$ 1,129
Cost of goods sold	1,308	61	1,976	870
Gross profit	551	24	1,030	259
Operating expenses:
Research and development	329	93	1,012	440
General and administrative	1,655	1,428	4,840	4,649
Total operating expenses	1,984	1,521	5,852	5,089
Loss from operations	(1,433)	(1,497)	(4,822)	(4,830)
Other income, net
Interest income	146	85	284	237
Government assistance	131	38	395	145
Gain from sale of assets				5
Other income, net	1	42	8	204
Total other income, net	278	165	687	591
Net loss	$ (1,155)	$ (1,332)	$ (4,135)	$ (4,239)
Net loss per share - basic	$ (0.02)	$ (0.03)	$ (0.09)	$ (0.11)
Weighted average number of shares outstanding - basic	54,714,910	38,562,127	46,986,914	38,459,313
Comprehensive loss
Net loss	$ (1,155)	$ (1,332)	$ (4,135)	$ (4,239)
Foreign-exchange translation adjustments, net of taxes	5	(1)	1	(13)
Comprehensive loss	$ (1,150)	$ (1,333)	$ (4,134)	$ (4,252)

XML

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock Private Placement	Common Stock	Additional Paid-in Capital Private Placement	Additional Paid-in Capital Private Warrants	Additional Paid-in Capital Private Pre-Funded Warrants	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Private Placement	Private Warrants	Private Pre-Funded Warrants	Total
Beginning Balance at Dec. 31, 2022		$ 4				$ 98,079	$ (8)	$ (88,523)				$ 9,552
Beginning Balances (in shares) at Dec. 31, 2022		38,023
Share-based compensation						227						227
Share-based compensation (in shares)		223
Fair value of stock issued in payment of accrued compensation						234						234
Fair value of stock issued in payment of accrued compensation (in shares)		296
Shares issued for services						3						3
Shares issued for services (per share) (in shares)		4
Net loss								(1,429)				(1,429)
Ending Balance at Mar. 31, 2023		$ 4				98,543	(8)	(89,952)				8,587
Ending Balances (in shares) at Mar. 31, 2023		38,546
Beginning Balance at Dec. 31, 2022		$ 4				98,079	(8)	(88,523)				9,552
Beginning Balances (in shares) at Dec. 31, 2022		38,023
Net loss												(4,239)
Ending Balance at Sep. 30, 2023		$ 4				98,725	(21)	(92,762)				5,946
Ending Balances (in shares) at Sep. 30, 2023		38,566
Beginning Balance at Mar. 31, 2023		$ 4				98,543	(8)	(89,952)				8,587
Beginning Balances (in shares) at Mar. 31, 2023		38,546
Share-based compensation						59						59
Shares issued for services						2						2
Shares issued for services (per share) (in shares)		4
Foreign-exchange translation adjustment							(12)					(12)
Shares issued upon exercise of options (in shares)		12
Net loss								(1,478)				(1,478)
Ending Balance at Jun. 30, 2023		$ 4				98,604	(20)	(91,430)				7,158
Ending Balances (in shares) at Jun. 30, 2023		38,562
Share-based compensation						119						119
Shares issued for services						2						2
Shares issued for services (per share) (in shares)		4
Foreign-exchange translation adjustment							(1)					(1)
Net loss								(1,332)				(1,332)
Ending Balance at Sep. 30, 2023		$ 4				98,725	(21)	(92,762)				5,946
Ending Balances (in shares) at Sep. 30, 2023		38,566
Beginning Balance at Dec. 31, 2023		$ 4				98,922	(17)	(93,717)				5,192
Beginning Balances (in shares) at Dec. 31, 2023		38,687
Share-based compensation						67						67
Share-based compensation (in shares)		67
Fair value of stock issued in payment of accrued compensation						326						326
Fair value of stock issued in payment of accrued compensation (in shares)		307
Shares issued for services						3						3
Shares issued for services (per share) (in shares)		4
Foreign-exchange translation adjustment							(3)					(3)
Tax withholdings related to share-based compensation						(16)						(16)
Tax withholdings related to share-based compensation (in Shares)		(22)
Net loss								(1,108)				(1,108)
Ending Balance at Mar. 31, 2024		$ 4				99,302	(20)	(94,825)				4,461
Ending Balances (in shares) at Mar. 31, 2024		39,043
Beginning Balance at Dec. 31, 2023		$ 4				98,922	(17)	(93,717)				5,192
Beginning Balances (in shares) at Dec. 31, 2023		38,687
Net loss												(4,135)
Ending Balance at Sep. 30, 2024		$ 5				112,686	(16)	(97,852)				14,823
Ending Balances (in shares) at Sep. 30, 2024		50,235
Beginning Balance at Mar. 31, 2024		$ 4				99,302	(20)	(94,825)				4,461
Beginning Balances (in shares) at Mar. 31, 2024		39,043
Share-based compensation						344						344
Share-based compensation (in shares)		256
Issuance of common stock in public offering, net of expenses		$ 1	$ 865			2,390			$ 865			2,391
Issuance of common stock in public offering, net of expenses (in shares)	2,250	5,314
Issuance of warrants in public offering, net of expenses			$ 2,389		$ 1,214	1,831			$ 2,389		$ 1,214	1,831
Issuance of common stock for participation right exercise, net of expenses				$ 2,250		1,447				$ 2,250		1,447
Issuance of common stock for participation right exercise, net of expenses (in shares)		3,350
Issuance of prefunded warrants for participation right exercise, net of expenses						580						580
Shares issued for services						3						3
Shares issued for services (per share) (in shares)		4
Foreign-exchange translation adjustment							(1)					(1)
Tax withholdings related to share-based compensation						(13)						(13)
Tax withholdings related to share-based compensation (in Shares)		(11)
Net loss								(1,872)				(1,872)
Ending Balance at Jun. 30, 2024		$ 5				112,602	(21)	(96,697)				15,889
Ending Balances (in shares) at Jun. 30, 2024		50,206
Share-based compensation						73						73
Shares issued for services						20						20
Shares issued for services (per share) (in shares)		29
Foreign-exchange translation adjustment							5					5
Tax withholdings related to share-based compensation						(9)						(9)
Net loss								(1,155)				(1,155)
Ending Balance at Sep. 30, 2024		$ 5				$ 112,686	$ (16)	$ (97,852)				$ 14,823
Ending Balances (in shares) at Sep. 30, 2024		50,235

XML

Condensed Consolidated Statement of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Share price of shares issued upon exercise of options (in dollars per share)		$ 0.54
Common stock issued for services one	$ 0.66	$ 0.66	$ 0.66

XML

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities:
Net loss	$ (4,135)	$ (4,239)
Adjustments to reconcile net loss to net cash used in operating activities:
Common stock issued for services	26	7
Share-based compensation	484	419
Reserve for share-based compensation tax withholdings	(38)
Depreciation and amortization	138	231
Impairment of intangible assets	17	14
Gain from sale of fixed assets		(5)
Right of use asset amortization	64	105
Realized gain from marketable securities		(79)
Lease amendments	(3)	(14)
Change in operating assets and liabilities:
Contract assets	39	13
Accounts receivable	(462)	(8)
Prepaid expenses and other assets	(260)	(116)
Accounts payable, accrued liabilities, and lease liabilities	1,091	6
Accrued compensation and related taxes	23	329
Contract liabilities	(942)	1,554
Net cash used in operating activities	(3,958)	(1,783)
Cash flows from investing activities:
Acquisition of fixed assets	(18)
Disbursements for patents and other intangible assets	(159)	(95)
Proceeds from sale of fixed assets		5
Purchases of held-to-maturity short-term U.S. treasuries		(2,162)
Redemption of held-to-maturity short-term U.S. treasuries		4,847
Net cash provided by (used in) investing activities	(177)	2,595
Cash flows from financing activities:
Proceeds from issuance of common stock, net of offering costs	12,967
Taxes paid related to vesting of restricted stock units	(31)	(15)
Net cash provided by (used in) financing activities	12,936	(15)
Effect of exchange rate changes on cash and cash equivalents	1	(13)
Net change in cash and cash equivalents	8,802	784
Cash and cash equivalents, beginning of period	5,684	6,451
Cash and cash equivalents, end of period	14,486	7,235
Supplemental disclosure of cash flow information:
Officer and employee equity awards for prior year accrued compensation	326	234
Prior year prepaid expenses repurposed to fixed assets as demonstration equipment		209
Non-cash impact of new lease	$ 32	$ 34

XML

Organization and Description of Business

9 Months Ended

Sep. 30, 2024

Organization and Description of Business

Organization and Description of Business

Note 1 – Organization and Description of Business

ClearSign Technologies Corporation (“ClearSign” or the “Company”) designs and develops products and technologies for the purpose of decarbonization and improving key performance characteristics of industrial and commercial systems, including operational performance, energy efficiency, emission reduction, safety, and overall cost-effectiveness. The Company’s patented technologies are designed to be embedded in established original equipment manufacturers (“OEM”) products as ClearSign Core™ and ClearSign Eye™ and other sensing configurations in order to enhance the performance of combustion systems and fuel safety systems in a broad range of markets. These markets include energy (upstream oil production and down-stream refining), commercial/industrial boiler, chemical, petrochemical, transport and power industries. The Company’s primary technology is its ClearSign Core technology, which achieves very low emissions without the need of selective catalytic reduction.

The Company was originally incorporated in the State of Washington in 2008. During January 2022, the Company relocated its headquarters from Seattle, Washington to Tulsa, Oklahoma. Effective June 15, 2023, the Company changed its state of incorporation to Delaware. On July 28, 2017, the Company incorporated a subsidiary, ClearSign Asia Limited, in Hong Kong to represent the Company’s business and technological interests throughout Asia. Through ClearSign Asia Limited, the Company has established a wholly foreign owned enterprise (“WFOE”) in China – ClearSign Combustion (Beijing) Environmental Technologies Co., LTD. On August 22, 2024, the Company’s Board of Directors (the “Board”) authorized management to move forward with filing for dormancy with Chinese regulators to suspend the Company’s Beijing, China operations. A dormancy filing allows the Company to keep its China legal entity in a suspended status for up to three years. The Company can revive its China operations at any time during those three years with minimal cost impact. Based on the Company’s current project plans, it expects to file for dormancy on or near December 31, 2024.

Unless otherwise stated or the context otherwise requires, the terms “we,” “us,” “our,” “ClearSign” and the “Company” refer to ClearSign Technologies Corporation and its subsidiary, ClearSign Asia Limited.

XML

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2024

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

Note 2 – Summary of Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for Form 10-Q. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet at December 31, 2023 has been derived from the Company’s audited consolidated financial statements as of that date.

In the opinion of management, these condensed consolidated financial statements reflect all normal recurring and other adjustments necessary for a fair presentation. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Operating results for interim periods are not necessarily indicative of operating results for an entire fiscal year or any other future periods.

The accompanying unaudited condensed consolidated financial statements include the accounts of ClearSign and its subsidiary. Intercompany balances and transactions have been eliminated in consolidation.

Liquidity

The Annual Report on Form 10-K filed with the SEC on April 1, 2024, contained a “going concern” note, which raised substantial doubt about our ability to continue as a going concern. We believe that we have alleviated the substantial doubt by selling equity securities on April 23, 2024, May 15, 2024, and June 24, 2024, which resulted in aggregate gross proceeds of approximately $14.2 million and net proceeds of approximately $13.0 million, after broker discounts and related fees. Refer to “Note 7 – Equity” for further details about the offerings effectuated during the nine months ended September 30, 2024.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Research and Development

The cost of research and development is expensed as incurred. Research and development costs consist of salaries, benefits, share-based compensation, consumables, and consulting fees, including costs to develop and test prototype equipment and parts. Research and development costs have been offset by funds received, if any, from strategic partners in cost sharing, collaborative projects. During the three and nine months ended September 30, 2024, the Company received $28 thousand and $135 thousand, respectively, from these arrangements. During the three and nine months ended September 30, 2023, the Company received $60 thousand from these arrangements.

Foreign Operations

The accompanying unaudited condensed consolidated balance sheets as of September 30, 2024 and December 31, 2023 include assets amounting to approximately $209 thousand and $334 thousand, respectively, relating to the operations of ClearSign Asia Limited. The Beijing registered capital requirement is $350 thousand, which is required to be paid by June 30, 2032, and of which $211 thousand has been paid as of September 30, 2024. On August 22, 2024, the Board authorized management to move forward with filing for dormancy with Chinese regulators to suspend the Company’s Beijing, China operations. A dormancy filing allows the Company to keep its China legal entity in a suspended status for up to three years. The Company can revive its China operations at any time during those three years with minimal cost impact. Based on the Company’s current project plans, it expects to file for dormancy on or near December 31, 2024. We will incur one-time non-recurring costs related to this project for severance and related benefit costs, equipment disposal and shipment costs, and legal filing fees. During the three months ended September 30, 2024, we recorded a one-time non-recurring $394 thousand accrual estimate related to our decision to suspend our China operations.

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). ASU 2023-07 requires expanded disclosures about reportable segments including additional information on segment expenses, expanded interim period disclosures, and an explanation of how the chief operating decision maker utilizes segment information in evaluating segment performance. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. We are currently assessing the impact that the adoption of ASU 2023-07 will have on the disclosures in our consolidated financial statements.

In December 2023, the FASB issued ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”). The FASB issued ASU 2023-09 to enhance the transparency and decision-making usefulness of income tax disclosures by requiring additional information on an entity's tax rate reconciliation, as well as

income taxes paid. ASU 2023-09 is effective for our reporting period beginning January 1, 2025. We are currently assessing the impact that the adoption of ASU 2023-09 will have on the disclosures in our consolidated financial statements.

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Fixed Assets

9 Months Ended

Sep. 30, 2024

Fixed Assets

Fixed Assets

Note 3 – Fixed Assets

Fixed Assets

Fixed assets are summarized as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Office furniture and equipment	$	78	$	60
Leasehold improvements		43		43
		121		103
Accumulated depreciation and amortization		(80)		(63)
		41		40
Operating lease ROU assets, net		204		235
Total	$	245	$	275

Depreciation expense for the three and nine months ended September 30, 2024 was $4 thousand and $15 thousand, respectively.

Depreciation expense for the three and nine months ended September 30, 2023 was $41 thousand and $122 thousand, respectively.

Leases

The Company leases office space in Tulsa, Oklahoma, Seattle, Washington, and Beijing, China. During the nine months ended September 30, 2024 and 2023, the Company renewed its Beijing, China lease for 13 months with monthly rent at approximately $3 thousand. As a result of these renewals, the Company increased the right-of-use (“ROU”) asset and lease liability by $32 thousand and $34 thousand during the nine months ended September 30, 2024 and 2023, respectively.

The Company exited our long term Seattle operating lease on September 30, 2023. During October 2023, the Company entered into a sub-lease agreement to rent office space in Seattle for approximately $2 thousand per month for twelve months. We renewed the twelve month Seattle sub-lease during October 2024 with substantially the same terms. The Tulsa and Beijing leases are classified as operating leases, with remaining terms ranging from less than twelve months to approximately four years; contractual language requires renewal negotiations to occur at or near termination. These leases are normal and customary for office space, in that, contractual guarantees exist requiring the lessee return the premises to its original functional state. The Company did not incur restoration expenses for the three and nine months ended September 30, 2024. The Company did not incur restoration expenses for the three months ended September 30, 2023, and incurred $31 thousand for the nine months ended September 30, 2023.

The Tulsa lease contains fixed annual lease payments that increase annually by 2%. The Seattle, Tulsa, and Beijing total monthly minimum rent is approximately $10 thousand. Operating lease costs for the three and nine months ended September 30, 2024 were $25 thousand and $73 thousand, respectively. Operating lease costs for the three and nine months ended September 30, 2023 were $35 thousand and $117 thousand, respectively.

Supplemental balance sheet information related to operating leases is as follows:

		September 30,			December 31,
(in thousands)		2024			2023
Operating lease ROU assets, net	$	204		$	235
Lease Liabilities:
Current lease liabilities	$	82		$	71
Long term lease liabilities		128			172
Total lease liabilities	$	210		$	243
Weighted average remaining lease term (in years):		2.7			2.4
Weighted average discount rate:		5.3	%		5.2	%

Supplemental cash flow information related to operating leases is as follows:

	For the Nine Months Ended
	September 30,
(in thousands)		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used in operating leases	$	73	$	134
Non-cash impact of new leases and lease modifications
Change in operating lease liabilities	$	29	$	25
Change in operating lease ROU assets	$	32	$	39

Minimum future payments under the Company’s operating lease liabilities as of September 30, 2024 are as follows:

	Discounted		Payments
	lease		due under
(in thousands)	liability		lease
	payments		agreements
2024 (remaining 3 months)	$	22	$	24
2025		75		82
2026		63		67
2027		50		52
Total	$	210	$	225

At September 30, 2024, $15 thousand of our future minimum lease payments represents interest.

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Patents and Other Intangible Assets

9 Months Ended

Sep. 30, 2024

Patents and Other Intangible Assets

Patents and Other Intangible Assets

Note 4 – Patents and Other Intangible Assets

Patents and other intangible assets are summarized as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Patents
Patents pending	$	351	$	477
Issued patents		1,011		810
		1,362		1,287
Trademarks
Trademarks pending		—		4
Registered trademarks		86		86
		86		90
Other		8		8
		1,456		1,385
Accumulated amortization		(601)		(549)
	$	855	$	836

Amortization expense for the three and nine months ended September 30, 2024 was $43 thousand and $123 thousand, respectively. Amortization expense for the three and nine months ended September 30, 2023 was $32 thousand and $109 thousand, respectively.

Future amortization expense associated with issued patents and registered trademarks as of September 30, 2024 is as follows:

(in thousands)
2024 (remaining 3 months)	$	41
2025		151
2026		121
2027		98
2028		62
Thereafter		23
	$	496

The amortization life for patents ranges between three to five years, with trademark lives set at ten years. The Company does not amortize patents or trademarks classified as pending.

During the three and nine months ended September 30, 2024 and 2023, the Company assessed its patent and trademark assets for impairment. The Company incurred $17 thousand impairment costs for the three and nine months ended September 30, 2024. The Company did not incur impairment costs for the three months ended September 30, 2023, and incurred $14 thousand impairment costs for the nine months ended September 30, 2023. The Company also evaluated its strategic approach to the pursuit and protection of its intellectual property. It is the intent of the Company to continue to pursue intellectual property protection.

If the Company identifies certain assets where the intellectual property does not directly align with its core technology, the Company will impair the intangible asset and write-off the asset as an expense.

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Revenue, Contract Assets and Contract Liabilities

9 Months Ended

Sep. 30, 2024

Revenue, Contract Assets and Contract Liabilities

Revenue, Contract Assets and Contract Liabilities

Note 5 – Revenue, Contract Assets and Contract Liabilities

The Company recognized $1,859 thousand of revenues and $1,308 thousand of cost of goods sold during the three months ended September 30, 2024. The revenue and cost of goods sold predominantly relate to the delivery of multiple

process burners to a single customer. The delivery of products constitutes performance obligations per Accounting Standards Codification (“ASC”) 606.

The Company recognized $3,006 thousand of revenues and $1,976 thousand of cost of goods sold during the nine months ended September 30, 2024. The revenue and cost of goods sold predominantly relate to the Company’s process burner product line. The Company delivered multiple burners for different customers, successfully completed engineering feasibility studies including computational fluid dynamic analysis, and fulfilled multiple spare parts orders. These products and services constitute performance obligations per ASC 606.

The Company recognized $85 thousand of revenues and $61 thousand of cost of goods sold during the three months ended September 30, 2023. The revenue and cost of goods sold relate to a sale of our boiler burner product line.

The Company recognized $1,129 thousand of revenues and $870 thousand of cost of goods sold during the nine months ended September 30, 2023. The revenue and cost of goods sold predominantly relate to the Company’s process burner product line, where the Company successfully completed a burner performance customer witness test, which represented a contractual performance obligation per ASC 606.

The Company had contract assets of $149 thousand and $188 thousand at September 30, 2024 and December 31, 2023, respectively. The Company had contract liabilities of $174 thousand and $1,116 thousand at September 30, 2024 and December 31, 2023, respectively. Of the $1,116 thousand contract liability balance at December 31, 2023, the Company recognized revenue of $772 thousand and $1,025 thousand during the three and nine months ended September 30, 2024, respectively.

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Product Warranties

9 Months Ended

Sep. 30, 2024

Product Warranties

Product Warranties

Note 6 – Product Warranties

A summary of the Company’s warranty liability activity, which is included in accrued liabilities in the accompanying consolidated balance sheets as of September 30, 2024 and December 31, 2023, is as follows:

	September 30,		December 31,
(in thousands)	2024		2023
Warranty liability at beginning of year	$	110	$	5
Accruals		268		105
Payments		(114)		—
Changes in accrual related to expirations		(3)		—
Warranty liability at end of period	$	261	$	110

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Equity

9 Months Ended

Sep. 30, 2024

Equity

Equity

Note 7 – Equity

Common Stock and Preferred Stock

The Company is authorized to issue 87.5 million shares of common stock and 2.0 million shares of preferred stock. Preferences, limitations, voting powers and relative rights of any preferred stock to be issued may be determined by the Board. The Company has not issued any shares of preferred stock.

In July 2018, in connection with a private placement of the Company’s common stock pursuant to a Stock Purchase Agreement, the Company granted clirSPV LLC (“clirSPV”) a right to purchase certain new equity securities that the Company sells for purpose of raising capital on terms and conditions no different from those offered to other purchasers (the “Participation Right”), so that clirSPV could maintain a 19.99% percentage ownership of the Company’s outstanding common stock. In no event may the Participation Right be exercised to the extent it would cause clirSPV or any of its affiliates to beneficially own 20% or more of the Company’s then outstanding common stock.

In May 2022, in connection with a waiver of the Participation Right’s notice requirements and other related closing mechanics for such Participation Right (the “Waiver”) the Company and clirSPV, agreed that the Participation Right may be extended from December 31, 2023, to such date that the holders of two-thirds of the outstanding units of clirSPV agree to extend each such holder’s existing agreement that he/she/it will have no right to force a redemption of his/her/its interests in clirSPV (the “Redemption Right”); provided, however, that the Participation Right could not be extended to a date later than June 30, 2027. On December 30, 2023, the Company received notice from clirSPV that the holders of at least two-thirds of the outstanding units of clirSPV agreed to extend the waiver of the Redemption Right until December 31, 2024. Accordingly, the Participation Right will now expire on December 31, 2024.

The Company has an At-The-Market (“ATM”) program pursuant to a Sales Agreement with Virtu Americas LLC, as sales agent, dated December 23, 2020 (the “Sales Agreement”), pursuant to which the Company may sell shares of common stock with an aggregate offering price of up to $8.7 million. On March 18, 2024, the Company filed a prospectus supplement suspending the ATM program. The Company will not make any sales of its common stock pursuant to the Sales Agreement unless and until a new prospectus supplement is filed with the SEC; however, the Sales Agreement remains in full force and effect. During the nine months ended September 30, 2024, the Company issued zero shares of its common stock from the ATM program. As of September 30, 2024, the Company has cumulatively issued approximately 1.6 million shares of common stock under the ATM program, at an average price of $3.84 per share. Gross proceeds totaled approximately $6.1 million and net cash proceeds was approximately $5.9 million.

The Company is currently subject to the SEC’s “baby shelf rules,” which prohibit companies with a public float of less than $75 million from issuing securities under a shelf registration statement in excess of one-third of such company’s public float in a 12-month period. These rules may limit future issuances of shares by the Company under our “shelf” registration statement on Form S-3, the ATM program or other securities offerings.

Equity Offerings 

Public Offering 

On April 23, 2024, we completed an underwritten public offering (the “Public Offering”), pursuant to which we sold approximately 4,621 thousand shares of our common stock and 4,621 thousand redeemable warrants (the “Public Warrants”) at a price of $0.91 per share of common stock and $0.01 for the accompanying Public Warrant. On May 15, 2024, Public Ventures, LLC (“Public Ventures”), the underwriter of the Public Offering, exercised its over-allotment option in full to purchase an additional 693 thousand shares of common stock and 693 thousand Public Warrants. After deducting customary professional service fees, the net proceeds from the Public Offering amounted to approximately $4,222 thousand.  

Each Public Warrant has an exercise price of $1.05 per share and is exercisable for a period of five years starting from the date of its issuance. Holders of the Public Warrants are not able to exercise their warrants on a cashless basis. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting the Company’s common stock. We have the option, but not the obligation, to redeem the Public Warrants anytime between issuance and expiration, at a price of $0.01 per Public Warrant, provided that the closing price of the common stock reported equals or exceeds $2.275 (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) per share for any 20 business days within a 30 consecutive business-day period.  

In connection with the Public Offering, we also issued approximately 425 thousand warrants to Public Ventures (the “Underwriter Warrants”), as consideration for the services provided as underwriter for the Public Offering. The Underwriter’s Warrants are exercisable at a per share exercise price of $1.1375 commencing 180 days from April 19, 2024, and expire on their fifth year anniversary. The Underwriter’s Warrants can be exercised on a cashless basis based on a formula set forth therein and are non-redeemable. 

The shares of common stock and Public Warrants issued in the Public Offering have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

(in thousands)		Allocated Amount
Common Stock	$	2,391
Public Warrants		1,831
	$	4,222

In determining the fair values of the Public Warrants and Underwriter Warrants, we used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

The Underwriter Warrants issued in connection with the Public Offering have been accounted for as a direct cost of the Public Offering, resulting in no net effect to the overall stockholders’ equity.

The fair value of the shares of common stock issued in the Public Offering was determined using the closing price of our common stock immediately preceding the closing date of the Public Offering. 

Private Placement 

On April 23, 2024, we completed a private placement (the “Private Placement”) concurrent with the Public Offering noted above. As part of the Private Placement, we sold (i) approximately 2,250 thousand shares of common stock at a price of $0.91 per share of common stock; (ii) redeemable warrants to purchase up to approximately 8,108 thousand shares of our common stock (the “Private Warrants”) at a price of $0.01 per accompanying Private Warrant; and (iii) pre-funded warrants to purchase up to approximately 3,156 thousand shares of common stock (the “Private Pre-Funded Warrants”) at a price of $0.9099 per accompanying Private Pre-Funded Warrant. After deducting customary professional service fees, the net proceeds from the Private Placement amounted to approximately $4,468 thousand. 

The Private Warrants have the same terms as the Public Warrants noted above, except that they are only exercisable six months after their issuance.  

Each Private Pre-Funded Warrant has an exercise price of $0.0001 per share and expire when exercised in full. In accordance with the terms of the Private Pre-Funded Warrants, the Company is prohibited from effecting an exercise of any Private Pre-Funded Warrants to the extent that such exercise would result in the number of shares of common stock beneficially owned by the holder and its affiliates exceeding 4.99% (or 9.99% at election of the holder) of the total number of shares of common stock outstanding immediately after giving effect to the exercise, which percentage may be increased or decreased at the holder’s election not to exceed 9.99%. 

In connection with the Private Placement, we issued approximately 432 thousand warrants to Public Ventures, as compensation for their services as our exclusive placement agent in the Private Placement (the “Placement Agent Warrants”). The terms of the Placement Agent Warrants are the same as the Underwriter Warrants noted above.  

The shares of common stock, Private Pre-Funded Warrants and Private Warrants issued in the Private Placement have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

(in thousands)		Allocated Amount
Common Stock	$	865
Private Pre-Funded Warrants		1,214
Private Warrants		2,389
	$	4,468

In determining the fair values of the Private Warrants, Private Pre-Funded Warrants, and Placement Agent Warrants, we used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

The Placement Agent Warrants issued in the Private Placement have been accounted for as a direct cost of the Private Placement resulting in no net effect to the overall stockholders’ equity.

The fair value of the shares of common stock issued in the Private Placement was determined using the closing price of our common stock immediately preceding the closing date of the Private Placement. 

Participation Right Exercise 

On June 24, 2024, in connection with the Public Offering and concurrent Private Placement noted above, clirSPV exercised its Participation Right (the “Participation Right Exercise”) and purchased (i) 3,350 thousand shares of our common stock at a price of $0.91 per share; (ii) redeemable warrants to purchase up to approximately 7,040 thousand shares of our common stock (the “Participation Right Warrants,” and together with the Public Warrants, Private Warrants, Underwriter Warrants, Placement Agent Warrants, the “Warrants”) at a price of $0.01 per accompanying Participation Right Warrant; and (iii) pre-funded warrants to purchase up to approximately 1,343 thousand shares of common stock (the “Participation Right Pre-Funded Warrants,” and together with the Private Pre-Funded Warrants, the “Pre-Funded Warrants”) at a price of $0.9099 per accompanying Participation Right Pre-Funded Warrant. After deducting customary professional service fees, the net proceeds from the Participation Right Exercise amounted to approximately $4,277 thousand.

The Participation Right Warrants have the same terms as the Private Warrants noted above. 

The Participation Right Pre-Funded Warrants have the same terms as the Private Pre-Funded Warrants noted above, except that, in accordance with the terms of the Participation Right Pre-Funded Warrants, the Company is prohibited from effecting an exercise that would result in beneficial ownership exceeding 19.99%.  

The shares of common stock, Participation Right Pre-Funded Warrants, and Participation Right Warrants issued in the Participation Right have been classified and recorded as part of stockholders’ equity. The amount allocated to such instruments were based on their relative fair value, resulting in an initial carrying value for each of those instruments to be as follows:

(in thousands)		Allocated Amount
Common Stock	$	1,447
Participation Right Pre-Funded Warrants		580
Participation Right Private Warrants		2,250
	$	4,277

In determining the fair values of the Participation Right Warrants and Participation Right Pre-Funded Warrants, the Company used a Black-Scholes option pricing model with the following assumptions: 

Stock price	$	0.65
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.25%
Expected dividend yield		0%

The fair value of the shares of common stock issued in connection with the Participation Right Exercise was determined using the closing price of the Company’s common stock immediately preceding the closing date of the Participation Right Exercise. 

Warrants & Pre-Funded Warrants 

The following table summarizes the Warrants (as defined above) and Pre-Funded Warrants (as defined above) activity and outstanding balance as of September 30, 2024, along with the associated weighted average exercise price and weighted average remaining life.  

	Warrants				Pre-Funded Warrants(1)
(in thousands, except per share data)	Number		Wtd. Avg. Exercise Price	Wtd. Avg. Remaining Life (in years)	Number		Wtd. Avg. Exercise Price
Beginning Balance	—		—	—	—		—
Granted	21,319	$	1.0535	4.99	4,499	$	0.0001
Exercised	—		—	—	—		—
Forfeited/Expired	—		—	—	—		—
Outstanding at Period End	21,319	$	1.0535	4.99	4,499	$	0.0001
(1) Pre-Funded warrants have no expiration date and only expire when exercised in full.

Equity Incentive Plan

On June 17, 2021, the Company's shareholders approved and the Company adopted the ClearSign Technologies Corporation 2021 Equity Incentive Plan (the “2021 Plan”) which permits the Company to grant incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance units, and performance shares, to eligible participants, which includes employees, directors and consultants. The Board’s Human Capital and Compensation Committee (the “Compensation Committee”) is authorized to administer the 2021 Plan.

The 2021 Plan provides for an annual increase in available shares equal to the lesser of (i) 10% of the aggregate number of shares of common stock issued by the Company in the prior fiscal year; or (ii) such number provided by the Compensation Committee; provided, however, that the total cumulative increase in the number of shares available for issuance pursuant to this automatic share increase shall not exceed 400 thousand shares of common stock. In 2024, the Board did not exercise their right to limit the automatic increase. Accordingly, the 2021 Plan share reserve increased by 66 thousand shares.

Ending balances for the 2021 Plan is as follows:

	September 30,	December 31,
(in thousands)	2024	2023
Outstanding options and restricted stock units	3,425	3,430
Reserved but unissued shares under the Plan	1,776	2,302
Total authorized shares under the Plan	5,201	5,732

Stock Options

Under the terms of the 2021 Plan, incentive stock options and nonstatutory stock options must have an exercise price at or above the fair market value on the date of the grant. At the time of grant, the Company will determine the period within which the option may be exercised and will specify any conditions that must be satisfied before the option vests and may be exercised. The Company estimates the fair value of stock options on the date of grant using the Black-Scholes option pricing model.

As permitted by SEC Staff Accounting Bulletin (“SAB”) 107, management utilized the simplified approach to estimate the expected term of the options, which represents the period of time that options granted are expected to be outstanding. Expected volatility has been determined through the Company’s historical stock price volatility. The Company has not made an estimate of forfeitures at the time of the grant, but rather accounts for forfeitures at the time they occur. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield in effect at the time of grant. The Company has never declared or paid dividends and has no plans to do so in the foreseeable future.

Equity Incentive Plan Options

Compensation expense associated with stock option awards for the three and nine months ended September 30, 2024 totaled $37 thousand and $87 thousand, respectively. Compensation expense associated with stock option awards for the three and nine months ended September 30, 2023 totaled $42 thousand and $132 thousand, respectively.

A summary of the Company’s 2011 Equity Incentive Plan and the 2021 Plan stock option activity and changes is as follows:

	September 30,
	2024
(in thousands, except per share data)	Options to Purchase Common Stock	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Outstanding at beginning of year	2,759	$	2.07	5.38
Granted	—	$	—	—
Exercised	—	$	—	—
Forfeited/Expired	(102)	$	0.88	—
Outstanding at end of period	2,657	$	2.11	4.83
Exercisable at end of period	1,947	$	1.75	4.40

The estimated aggregate pretax intrinsic value of the Company’s outstanding vested stock options at September 30, 2024 is $21 thousand. The intrinsic value is the difference between the Company’s common stock price and the option exercise prices multiplied by the number of in-the-money options. This amount changes based on the fair value of the Company’s common stock.

At September 30, 2024, there was $315 thousand of total unrecognized compensation cost related to non-vested stock option-based compensation arrangements. Vesting criteria ranges from time-based to performance-based. The Company records costs for time-based arrangements ratably across the timeframe, whereas performance-based arrangements require management to continually evaluate predetermined goals against actual circumstances.

Inducement Options

During the year ended December 31, 2023, the Company granted non-qualified stock options to its Chief Technology Officer to purchase an aggregate of 150 thousand shares of common stock with an exercise price of $0.91 as a material inducement to accept employment with the Company. These inducement options vest in three equal installments, with one third of the option vesting on the grant date, and each remaining third vesting on the second and third anniversaries

of the grant date, subject to continued employment with the Company. The fair value of these options were estimated on the grant date using the Black-Scholes valuation model, and totaled $112 thousand. The compensation expense recognized for these awards for the three and nine months ended September 30, 2024, was $9 thousand and $28 thousand, respectively. During the three and nine months ended September 30, 2023, compensation expense for these options was zero.

During the nine months ended September 30, 2023, the Company granted non-qualified stock options to its Director of Customer Relationships and Business Development to purchase an aggregate of 150 thousand shares of common stock with an exercise price of $1.31 as a material inducement to accept employment with the Company. These inducement options vest in three equal installments, with one third of the option vesting on the grant date, and each remaining third vesting on the second and third anniversaries of the grant date, subject to continued employment with the Company. The fair value of these options were estimated on the grant date using the Black-Scholes valuation model, which resulted in $160 thousand. The compensation expense recognized for these awards for the three and nine months ended September 30, 2023 was $62 thousand. During the three months ended December 30, 2023, two-thirds of these inducement options were forfeited upon the departure of the Director of Customer Relationships and Business Development.

These inducement options were granted outside of the 2021 Plan and in accordance with the employment inducement

exemption provided under Nasdaq Listing Rule 5635(c)(4).

Restricted Stock Units

The Company awards employees and directors restricted stock units (“RSUs”) in lieu of cash payment for compensation. These awards are granted from the 2021 Plan. Employee vesting criteria is time based, and compensation expense is recognized ratably across the timeframe. The Company pays payroll withholding taxes on behalf of the employee at vesting, and withholds shares from the employee’s award to cover the taxes payable. The Company accrued taxes for RSU share-based compensation of $38 thousand and $15 thousand for the nine months ended September 30, 2024 and 2023, respectively.

Director vesting criteria is contingent upon the occurrence of one of four future events, which the Company cannot predict or control. Therefore, compensation expense for director RSUs is not recognized until one of these four future events occur, which is in accordance with FASB ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”). Total unrecognized compensation expense for director services as of September 30, 2024 was $501 thousand. Director compensation is earned on a quarterly basis with the target value of compensation set at $79 thousand per quarter, assuming four directors; one lead independent director; one chair for each committee; and two committee members for each of the three committees.

A summary of the Company’s RSUs activity is as follows:

	September 30,
	2024
(in thousands, except per share data)	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested at beginning of period	671	$	1.05
Granted	420	$	1.00
Vested	(323)	$	1.08
Forfeited	—	$	—
Nonvested at end of period	768	$	1.01

A summary of the Company’s RSU compensation expense is as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024			2023
Compensation Expense	$	27	$	15	$	369	$	225
Weighted Average Value Per Share	$	0.93	$	0.80	$	1.29	$	0.80

Stock Awards

The Company awards employees stock in lieu of cash payment for compensation, typically to satisfy accrued bonus compensation. The awards are granted from the 2021 Plan.

	For the Nine Months Ended
	September 30,
(in thousands, except per share data)	2024		2023
Fair value	$	326	$	234
Weighted Average Value Per Share	$	1.06	$	0.79

For the three months ended for September 30, 2024 and 2023, the Company issued zero stock awards respectively.

Consultant Stock Plan

The 2013 Consultant Stock Plan (the “Consultant Plan”) provides for the granting of shares of common stock to consultants who provide services related to capital raising, investor relations, and making a market in or promoting the Company’s securities. The Company’s officers, employees, and Board members are not entitled to receive grants from the Consultant Plan. The Compensation Committee is authorized to administer the Consultant Plan and establish the grant terms. The Consultant Plan provides for quarterly increases in the available number of authorized shares equal to the lesser of 1% of any new shares issued by the Company during the quarter immediately prior to the adjustment date or such lesser amount as the Board shall determine.

The Consultant Plan activity is as follows:

	September 30,
(in thousands)	2024
Reserved but unissued shares at beginning of period		188
Increases in the number of authorized shares		115
Grants		(36)
Reserved but unissued shares at end of period		267

The Consultant Plan compensation expense is summarized as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024		2023
Compensation Expense	$	20	$	2	$	26	$	7
Weighted Average Value Per Share	$	0.72	$	0.66	$	0.74	$	0.66

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Net Loss Per Common Share

9 Months Ended

Sep. 30, 2024

Net Loss Per Common Share

Net Loss Per Common Share

Note 8 – Net Loss per Common Share

The Company calculates net loss per common share in accordance with ASC 260 “Earnings Per Share” (“ASC 260”). Basic and diluted net loss per common share was determined by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Under ASC 260, shares issuable for little or no cash consideration are considered outstanding common shares and included in the computation of basic net loss per share. As such, for the three and nine months ended September 30, 2024, the Company included Pre-Funded Warrants to purchase shares of common stock in its computation of net loss per share. The Pre-Funded Warrants were issued in April and June 2024 with an exercise price of $0.0001 (See "Note 7 - Equity" for additional information).

The following potentially dilutive securities have not been included in the computation of diluted net loss per share for the three and nine months ended September 30, 2024 and 2023, as the result would be anti-dilutive:

	September 30,	September 30,
(in thousands)	2024	2023
Stock Options	3,148	3,250
Restricted Stock Units	768	708
Warrants	21,319	-
Total shares excluded from calculation	25,235	3,958

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Commitments and Contingencies

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies.

Commitments and Contingencies

Note 9 – Commitments and Contingencies

Litigation

From time to time the Company may become involved in various lawsuits and legal proceedings which arise in the ordinary course of business. Litigation is subject to inherent uncertainties and an adverse result in any such matter may harm the Company’s business. As of the date of this report, the Company is not a party to any material pending legal proceedings or claims that the Company believes will have a material adverse effect on the business, financial condition or operating results.

Indemnification Agreements

The Company maintains indemnification agreements with our directors and officers that may require the Company to indemnify these individuals against liabilities that arise by reason of their status or service as directors or officers, except as prohibited by law.

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Government Assistance

9 Months Ended

Sep. 30, 2024

Government Assistance

Government Assistance

Note 10 – Government Assistance

During 2022, the Company was awarded a research grant from the Department of Energy (“DOE”) for approximately $250 thousand with the completion of such grant occurring in March 2023. The purpose of the grant was to produce a research paper for a flexible fuel ultra-low NOx process burner capable of burning 100% hydrogen fuel. During 2023, the Company was awarded a Phase 2 grant from the DOE to continue developing this ultra-low NOx hydrogen burner. The Phase 2 grant amount totaled approximately $1.6 million over a two-year period. These awards allow the Company to request reimbursements for expenditures such as labor, material, and administrative costs. During the three and nine months ended September 30, 2024, the Company recognized $116 thousand and $332 thousand in reimbursements from the DOE, respectively. During the three and nine months ended September 30, 2023, the Company recognized $26 thousand and $95 thousand in reimbursements from the DOE, respectively.

Beginning in 2021, the Company received funds relating to the Oklahoma 21^st Century Quality Jobs Act. The estimated duration of the program is up to 10 years and is designed to attract growth industries to Oklahoma. By reporting quarterly salary statistics and meeting agreed upon employment thresholds, the state remits benefit monies to the Company. During three and nine months ended September 30, 2024, the Company recognized $17 thousand and $64 thousand in government assistance from this program, respectively. During three and nine months ended September 30, 2023, the Company recognized $12 thousand and $51 thousand in government assistance from this program, respectively.

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Subsequent Events

9 Months Ended

Sep. 30, 2024

Subsequent Events

Subsequent Events

Note 11 – Subsequent Events

The Company has evaluated subsequent events as of the date of this report and has none to report.

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Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (1,155)	$ (1,332)	$ (4,135)	$ (4,239)

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Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Rule 10b5-1 Arrangement Modified	false
Non-Rule 10b5-1 Arrangement Modified	false

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Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2024

Summary of Significant Accounting Policies

Basis of Presentation

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for Form 10-Q. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet at December 31, 2023 has been derived from the Company’s audited consolidated financial statements as of that date.

In the opinion of management, these condensed consolidated financial statements reflect all normal recurring and other adjustments necessary for a fair presentation. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023. Operating results for interim periods are not necessarily indicative of operating results for an entire fiscal year or any other future periods.

The accompanying unaudited condensed consolidated financial statements include the accounts of ClearSign and its subsidiary. Intercompany balances and transactions have been eliminated in consolidation.

Liquidity

Liquidity

The Annual Report on Form 10-K filed with the SEC on April 1, 2024, contained a “going concern” note, which raised substantial doubt about our ability to continue as a going concern. We believe that we have alleviated the substantial doubt by selling equity securities on April 23, 2024, May 15, 2024, and June 24, 2024, which resulted in aggregate gross proceeds of approximately $14.2 million and net proceeds of approximately $13.0 million, after broker discounts and related fees. Refer to “Note 7 – Equity” for further details about the offerings effectuated during the nine months ended September 30, 2024.

Use of Estimates

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Research and Development

Research and Development

The cost of research and development is expensed as incurred. Research and development costs consist of salaries, benefits, share-based compensation, consumables, and consulting fees, including costs to develop and test prototype equipment and parts. Research and development costs have been offset by funds received, if any, from strategic partners in cost sharing, collaborative projects. During the three and nine months ended September 30, 2024, the Company received $28 thousand and $135 thousand, respectively, from these arrangements. During the three and nine months ended September 30, 2023, the Company received $60 thousand from these arrangements.

Foreign Operations

Foreign Operations

The accompanying unaudited condensed consolidated balance sheets as of September 30, 2024 and December 31, 2023 include assets amounting to approximately $209 thousand and $334 thousand, respectively, relating to the operations of ClearSign Asia Limited. The Beijing registered capital requirement is $350 thousand, which is required to be paid by June 30, 2032, and of which $211 thousand has been paid as of September 30, 2024. On August 22, 2024, the Board authorized management to move forward with filing for dormancy with Chinese regulators to suspend the Company’s Beijing, China operations. A dormancy filing allows the Company to keep its China legal entity in a suspended status for up to three years. The Company can revive its China operations at any time during those three years with minimal cost impact. Based on the Company’s current project plans, it expects to file for dormancy on or near December 31, 2024. We will incur one-time non-recurring costs related to this project for severance and related benefit costs, equipment disposal and shipment costs, and legal filing fees. During the three months ended September 30, 2024, we recorded a one-time non-recurring $394 thousand accrual estimate related to our decision to suspend our China operations.

Recently Issued Accounting Pronouncements

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). ASU 2023-07 requires expanded disclosures about reportable segments including additional information on segment expenses, expanded interim period disclosures, and an explanation of how the chief operating decision maker utilizes segment information in evaluating segment performance. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. We are currently assessing the impact that the adoption of ASU 2023-07 will have on the disclosures in our consolidated financial statements.

In December 2023, the FASB issued ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”). The FASB issued ASU 2023-09 to enhance the transparency and decision-making usefulness of income tax disclosures by requiring additional information on an entity's tax rate reconciliation, as well as

income taxes paid. ASU 2023-09 is effective for our reporting period beginning January 1, 2025. We are currently assessing the impact that the adoption of ASU 2023-09 will have on the disclosures in our consolidated financial statements.

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Fixed Assets (Tables)

9 Months Ended

Sep. 30, 2024

Fixed Assets

Summary of Fixed Assets

	September 30,		December 31,
(in thousands)	2024		2023
Office furniture and equipment	$	78	$	60
Leasehold improvements		43		43
		121		103
Accumulated depreciation and amortization		(80)		(63)
		41		40
Operating lease ROU assets, net		204		235
Total	$	245	$	275

Schedule Of Supplemental Information

		September 30,			December 31,
(in thousands)		2024			2023
Operating lease ROU assets, net	$	204		$	235
Lease Liabilities:
Current lease liabilities	$	82		$	71
Long term lease liabilities		128			172
Total lease liabilities	$	210		$	243
Weighted average remaining lease term (in years):		2.7			2.4
Weighted average discount rate:		5.3	%		5.2	%

Supplemental cash flow information related to leases

	For the Nine Months Ended
	September 30,
(in thousands)		2024		2023
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used in operating leases	$	73	$	134
Non-cash impact of new leases and lease modifications
Change in operating lease liabilities	$	29	$	25
Change in operating lease ROU assets	$	32	$	39

Schedule of minimum future payments

	Discounted		Payments
	lease		due under
(in thousands)	liability		lease
	payments		agreements
2024 (remaining 3 months)	$	22	$	24
2025		75		82
2026		63		67
2027		50		52
Total	$	210	$	225

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Patents and Other Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2024

Patents and Other Intangible Assets

Schedule of Patents and Other Intangible Assets

	September 30,		December 31,
(in thousands)	2024		2023
Patents
Patents pending	$	351	$	477
Issued patents		1,011		810
		1,362		1,287
Trademarks
Trademarks pending		—		4
Registered trademarks		86		86
		86		90
Other		8		8
		1,456		1,385
Accumulated amortization		(601)		(549)
	$	855	$	836

Schedule of future amortization expense

(in thousands)
2024 (remaining 3 months)	$	41
2025		151
2026		121
2027		98
2028		62
Thereafter		23
	$	496

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Product Warranties (Tables)

9 Months Ended

Sep. 30, 2024

Product Warranties

Summary of warranty liability activity

	September 30,		December 31,
(in thousands)	2024		2023
Warranty liability at beginning of year	$	110	$	5
Accruals		268		105
Payments		(114)		—
Changes in accrual related to expirations		(3)		—
Warranty liability at end of period	$	261	$	110

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Equity (Tables)

9 Months Ended

Sep. 30, 2024

Schedule of outstanding, reserved and authorized shares under share-based compensation plans

	September 30,	December 31,
(in thousands)	2024	2023
Outstanding options and restricted stock units	3,425	3,430
Reserved but unissued shares under the Plan	1,776	2,302
Total authorized shares under the Plan	5,201	5,732

Schedule of stock option activity

	September 30,
	2024
(in thousands, except per share data)	Options to Purchase Common Stock	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (in years)
Outstanding at beginning of year	2,759	$	2.07	5.38
Granted	—	$	—	—
Exercised	—	$	—	—
Forfeited/Expired	(102)	$	0.88	—
Outstanding at end of period	2,657	$	2.11	4.83
Exercisable at end of period	1,947	$	1.75	4.40

Schedule of restricted stock unit activity

	September 30,
	2024
(in thousands, except per share data)	Number of Shares	Weighted Average Grant Date Fair Value
Nonvested at beginning of period	671	$	1.05
Granted	420	$	1.00
Vested	(323)	$	1.08
Forfeited	—	$	—
Nonvested at end of period	768	$	1.01

Schedule of share-based compensation activity

	September 30,
(in thousands)	2024
Reserved but unissued shares at beginning of period		188
Increases in the number of authorized shares		115
Grants		(36)
Reserved but unissued shares at end of period		267

Schedule of initial carrying value

(in thousands)		Allocated Amount
Common Stock	$	2,391
Public Warrants		1,831
	$	4,222

(in thousands)		Allocated Amount
Common Stock	$	865
Private Pre-Funded Warrants		1,214
Private Warrants		2,389
	$	4,468

(in thousands)		Allocated Amount
Common Stock	$	1,447
Participation Right Pre-Funded Warrants		580
Participation Right Private Warrants		2,250
	$	4,277

Schedule of public warrants and underwriter warrants

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

Stock price	$	0.79
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.64%
Expected dividend yield		0%

Stock price	$	0.65
Expected volatility		108.01%
Contractual/expected term (in years)		5.00
Risk-free interest rate		4.25%
Expected dividend yield		0%

Summary of warrants outstanding

	Warrants				Pre-Funded Warrants(1)
(in thousands, except per share data)	Number		Wtd. Avg. Exercise Price	Wtd. Avg. Remaining Life (in years)	Number		Wtd. Avg. Exercise Price
Beginning Balance	—		—	—	—		—
Granted	21,319	$	1.0535	4.99	4,499	$	0.0001
Exercised	—		—	—	—		—
Forfeited/Expired	—		—	—	—		—
Outstanding at Period End	21,319	$	1.0535	4.99	4,499	$	0.0001
(1) Pre-Funded warrants have no expiration date and only expire when exercised in full.

Restricted Stock Units (RSUs) [Member]

Schedule of compensation expense

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024			2023
Compensation Expense	$	27	$	15	$	369	$	225
Weighted Average Value Per Share	$	0.93	$	0.80	$	1.29	$	0.80

Equity Incentive Plan

Schedule of compensation expense

	For the Nine Months Ended
	September 30,
(in thousands, except per share data)	2024		2023
Fair value	$	326	$	234
Weighted Average Value Per Share	$	1.06	$	0.79

Consultant Stock Plan

Schedule of compensation expense

	For the Three Months Ended				For the Nine Months Ended
	September 30,				September 30,
(in thousands, except per share data)	2024		2023		2024		2023
Compensation Expense	$	20	$	2	$	26	$	7
Weighted Average Value Per Share	$	0.72	$	0.66	$	0.74	$	0.66

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Net Loss Per Common Share (Tables)

9 Months Ended

Sep. 30, 2024

Net Loss Per Common Share

Schedule of potentially dilutive securities that have not been included in the computation of diluted net loss per share

	September 30,	September 30,
(in thousands)	2024	2023
Stock Options	3,148	3,250
Restricted Stock Units	768	708
Warrants	21,319	-
Total shares excluded from calculation	25,235	3,958

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Organization and Description of Business (Details) - USD ($) $ in Thousands	Aug. 22, 2024	Sep. 30, 2024	Dec. 31, 2023
Organization and Description of Business [Line Items]
Cash and cash equivalents		$ 14,486	$ 5,684
(Losses) since inception		$ 97,852	$ 93,717
Suspended status | ClearSign Asia Limited [Member]
Organization and Description of Business [Line Items]
Suspended status, period	3 years

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Summary of Significant Accounting Policies - Liquidity (Details) - USD ($) $ in Thousands				9 Months Ended
	Jun. 24, 2024	May 15, 2024	Apr. 23, 2024	Sep. 30, 2024
Summary of Significant Accounting Policies
Gross proceeds from the offering	$ 14,200	$ 14,200	$ 14,200
Net proceeds	$ 13,000	$ 13,000	$ 13,000	$ 12,967

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Summary of Significant Accounting Policies - Research and Development (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Summary of Significant Accounting Policies
Research and Development costs have been offset by funds received	$ 28	$ 60	$ 135	$ 60

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Summary of Significant Accounting Policies - Foreign Operations (Details) - USD ($) $ in Thousands		3 Months Ended
	Aug. 22, 2024	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Assets		$ 17,094	$ 7,620
ClearSign Asia Limited [Member] | Suspended status
Property, Plant and Equipment [Line Items]
Suspended status, period	3 years
ClearSign Asia Limited
Property, Plant and Equipment [Line Items]
Assets		209	$ 334
Registered capital requirement		350
Capital requirement paid		211
ClearSign Asia Limited | ClearSign Asia Limited [Member] | Suspended status
Property, Plant and Equipment [Line Items]
Suspended status, period	3 years
One-time non-recurring accrual estimate related to our decision to suspend our China operations		$ 394

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Fixed Assets - Summary (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Fixed Assets
Office furniture and equipment	$ 78		$ 78		$ 60
Leasehold improvements	43		43		43
Fixed assets, gross	121		121		103
Accumulated depreciation and amortization	(80)		(80)		(63)
Fixed assets, net, after accumulated amortization	41		41		40
Operating lease ROU assets, net	204		204		235
Total	245		245		$ 275
Depreciation expense	$ 4	$ 41	$ 15	$ 122

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Fixed Assets - Leases (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases
Increase (decrease) in operating lease right of use asset				$ 32,000	$ 34,000
Restoration expense		$ 0	$ 0	0	31,000
Operating lease cost		$ 25,000	$ 35,000	$ 73,000	$ 117,000
CHINA
Leases
Renewal option term		13 months	13 months	13 months	13 months
Short term monthly rent expense				$ 3,000	$ 3,000
Seattle and Tulsa
Leases
Short term monthly rent expense	$ 2,000
Agreement expiration term (in years)	12 months
Annual rent expense, increase (in percent)				2.00%
Monthly rent expense				$ 10,000
Minimum | Seattle and Tulsa
Leases
Remaining term (in years)	12 months
Maximum | Seattle and Tulsa
Leases
Remaining term (in years)	4 years

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Fixed Assets - Leases - Supplemental balance sheet and cash flow information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Operating Lease
Operating lease ROU assets, net	$ 204		$ 235
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net		Property, Plant and Equipment, Net
Lease Liabilities:
Current lease liabilities	$ 82		$ 71
Long term lease liabilities	128		172
Total lease liabilities	$ 210		$ 243
Weighted average remaining lease term (in years)	2 years 8 months 12 days		2 years 4 months 24 days
Weighted average discount rate	5.30%		5.20%
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used in operating leases	$ 73	$ 134
Change in operating lease liabilities	29	25
Change in operating lease ROU assets	$ 32	$ 39

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Fixed Assets - Minimum future lease payments (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Fixed Assets
Discounted lease liability payments, 2024 remaining 3 months)	$ 22
Discounted lease liability payments, 2025	75
Discounted lease liability payments, 2026	63
Discounted lease liability payments, 2027	50
Total discounted lease liability payments	210
Payments due under lease agreements, 2024 remaining 3 months)	24
Payments due under lease agreements, 2025	82
Payments due under lease agreements, 2026	67
Payments due under lease agreements, 2027	52
Total payments due under lease agreements	225
Interest on future minimum payments	$ 15

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Patents and Other Intangible Assets - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Patents	$ 1,362	$ 1,287
Trademarks	86	90
Other	8	8
Patents and other intangible assets	1,456	1,385
Accumulated amortization	(601)	(549)
Finite-Lived Intangible Assets, Net	855	836
Patents pending
Patents	351	477
Issued patents
Patents	1,011	810
Trademarks pending
Trademarks		4
Registered trademarks
Trademarks	$ 86	$ 86

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Patents and Other Intangible Assets - Future amortization expense (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Patents and Other Intangible Assets
2024 (remaining 3 months)	$ 41
2025	151
2026	121
2027	98
2028	62
Thereafter	23
Finite-Lived Intangible Assets, Net	$ 496

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Patents and Other Intangible Assets - Additional information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Intangible assets
Amortization expense	$ 43	$ 32	$ 123	$ 109
Impairment			$ 17	$ 14
Minimum
Intangible assets
Amortization life (in years)	3 years		3 years
Maximum
Intangible assets
Amortization life (in years)	5 years		5 years
Patent and trademark
Intangible assets
Impairment	$ 17	$ 0	$ 17
Trademarks [Member]
Intangible assets
Amortization life (in years)	10 years		10 years

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Revenue, Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Revenue, Contract Assets and Contract Liabilities
Revenues	$ 1,859	$ 85	$ 3,006	$ 1,129
Cost of goods sold	1,308	$ 61	1,976	$ 870
Contract assets	149		149		$ 188
Contract liabilities	174		174		$ 1,116
Revenue recognized	$ 772		$ 1,025

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Product Warranties (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Product Warranties
Warranty liability at beginning of year	$ 110	$ 5
Accruals	268	105
Payments	(114)
Changes in accrual related to expirations	(3)
Warranty liability at end of period	$ 261	$ 110

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Equity - Common Stock and Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended	9 Months Ended
	Dec. 30, 2023	Dec. 23, 2020	May 31, 2022	Jun. 30, 2024	Sep. 30, 2024	Jul. 31, 2018
Stockholders' equity
Common stock, authorized shares					87,500,000
Preferred stock, authorized shares					2,000,000.0
Percentage of Participation right extended			0.67%
Minimum
Stockholders' equity
Percentage of Redemption right extended	0.67%
ATM
Stockholders' equity
Aggregate offering price		$ 8.7
Participation Right
Stockholders' equity
Stock issued, investor, beneficial ownership percentage						19.99%
Maximum beneficial ownership (as a percent)						20.00%
Common Stock
Stockholders' equity
Number of shares of common stock issued				5,314,000
Common Stock | ATM
Stockholders' equity
Number of shares of common stock issued					0
Number of shares issued to date					1,600,000
Share price of shares issued in offering (in dollars per share)					$ 3.84
Gross proceeds to date					$ 6.1
Net proceeds to date					$ 5.9

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Equity - Equity Offerings (Details) $ / shares in Units, shares in Thousands, $ in Thousands				3 Months Ended	9 Months Ended
	Jun. 24, 2024 USD ($) $ / shares	May 15, 2024 USD ($) shares	Apr. 23, 2024 USD ($) D $ / shares shares	Jun. 30, 2024 shares	Sep. 30, 2024 USD ($)	Jul. 31, 2018
Stockholders' equity
Fair value of common stock (in dollars per share) | $ / shares	$ 0.91
Net proceeds | $	$ 13,000	$ 13,000	$ 13,000		$ 12,967
Public offering
Stockholders' equity
Net proceeds | $		$ 4,222
Private Placement
Stockholders' equity
Net proceeds | $			$ 4,468
Participation Right
Stockholders' equity
Maximum beneficial ownership (as a percent)						20.00%
Public ventures | Over-allotment option
Stockholders' equity
Redeemable warrants | shares		693
Additional shares purchased | shares		693
Private Warrants | Private Placement
Stockholders' equity
Offering price per warrant | $ / shares			$ 0.01
Warrants for purchase (in shares) | shares			8,108
Exercisable period			6 months
Public Warrants | Public offering
Stockholders' equity
Number of shares of common stock issued | shares			4,621
Redeemable warrants | shares			4,621
Fair value of common stock (in dollars per share) | $ / shares			$ 0.91
Offering price per warrant | $ / shares			0.01
Exercise price (in dollars per share) | $ / shares			$ 1.05
Term of warrants			5 years
Business days | D			20
Consecutive business day period | D			30
Public Warrants | Public offering | Minimum
Stockholders' equity
Share price target | $ / shares			$ 2.275
Private Pre-Funded Warrants | Private Placement
Stockholders' equity
Offering price per warrant | $ / shares			0.9099
Exercise price (in dollars per share) | $ / shares			$ 0.0001
Warrants for purchase (in shares) | shares			3,156
Maximum beneficial ownership (as a percent)			4.99%
Maximum Percentage of shares owned at the election of holder			9.99
Underwriter warrants | Public ventures | Public offering
Stockholders' equity
Redeemable warrants | shares			425
Fair value of common stock (in dollars per share) | $ / shares			$ 1.1375
Threshold number of days | D			180
Placement Agent Warrants | Public ventures | Private Placement
Stockholders' equity
Redeemable warrants | shares			432
Common Stock
Stockholders' equity
Number of shares of common stock issued | shares				5,314
Common Stock | Private Placement
Stockholders' equity
Number of shares of common stock issued | shares			2,250	2,250
Common Stock | Public Warrants
Stockholders' equity
Fair value of common stock (in dollars per share) | $ / shares			$ 0.91

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Equity - Allocated Amount (Details) - USD ($) $ in Thousands		3 Months Ended
	Apr. 23, 2024	Jun. 30, 2024
Stockholders' equity
Common Stock		$ 2,391
Warrants		1,831
Private Pre-Funded Warrants
Stockholders' equity
Warrants		1,214
Public offering
Stockholders' equity
Common Stock	$ 2,391
Warrants	1,831
Total Allocated Amount	4,222
Private Placement
Stockholders' equity
Common Stock	865	865
Warrants		$ 2,389
Private Placement | Private Pre-Funded Warrants and Private Warrants
Stockholders' equity
Total Allocated Amount	4,468
Private Placement | Private Pre-Funded Warrants
Stockholders' equity
Warrants	1,214
Private Placement | Private Warrants
Stockholders' equity
Warrants	$ 2,389

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Equity - Warrants, Assumptions (Details)	Sep. 30, 2024 $ / shares	Apr. 23, 2024 USD ($)
Stock Price
Stockholders' equity
Warrants, Assumptions | $ / shares	0.79
Stock Price | Private Placement
Stockholders' equity
Warrants, Assumptions		0.79
Expected Volatility
Stockholders' equity
Warrants, Assumptions	108.01
Expected Volatility | Private Placement
Stockholders' equity
Warrants, Assumptions		108.01
Contractual/expected term (in years)
Stockholders' equity
Warrants, Assumptions	5.00
Contractual/expected term (in years) | Private Placement
Stockholders' equity
Warrants, Assumptions		5.00
Risk-free interest rate
Stockholders' equity
Warrants, Assumptions	4.64
Risk-free interest rate | Private Placement
Stockholders' equity
Warrants, Assumptions		4.64
Expected dividend yield
Stockholders' equity
Warrants, Assumptions	0
Expected dividend yield | Private Placement
Stockholders' equity
Warrants, Assumptions		0

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Equity - Participation Right Exercise (Details) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
	Jun. 24, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Sep. 30, 2024 $ / shares
Stockholders' equity
Number of shares of common stock issued | shares	3,350
Share price per share | $ / shares	$ 0.91
Net proceeds	$ 4,277
Common Stock, Allocated amount	$ 1,447	$ 1,447
Warrants, Allocated amount		$ 580
Stock Price
Stockholders' equity
Warrants, Assumptions | $ / shares			0.79
Expected Volatility
Stockholders' equity
Warrants, Assumptions			108.01
Contractual/expected term (in years)
Stockholders' equity
Warrants, Assumptions			5.00
Risk-free interest rate
Stockholders' equity
Warrants, Assumptions			4.64
Expected dividend yield
Stockholders' equity
Warrants, Assumptions			0
Participation Right Warrants
Stockholders' equity
Shares issuable for warrants | shares	7,040
Warrant price | $ / shares	$ 0.01
Participation Right Warrants | Stock Price
Stockholders' equity
Warrants, Assumptions	0.65
Participation Right Warrants | Expected Volatility
Stockholders' equity
Warrants, Assumptions	108.01
Participation Right Warrants | Contractual/expected term (in years)
Stockholders' equity
Warrants, Assumptions	5.00
Participation Right Warrants | Risk-free interest rate
Stockholders' equity
Warrants, Assumptions	4.25
Participation Right Warrants | Expected dividend yield
Stockholders' equity
Warrants, Assumptions	0
Participation Right Pre-Funded Warrants
Stockholders' equity
Shares issuable for warrants | shares	1,343
Warrant price | $ / shares	$ 0.9099
Maximum Percentage of shares owned at the election of holder	19.99
Warrants, Allocated amount	$ 580
Participation Right Private Warrants
Stockholders' equity
Warrants, Allocated amount	$ 2,250

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Equity - Warrants & Pre-Funded Warrants (Details)	3 Months Ended
	Sep. 30, 2024 $ / shares shares
Warrants
Stockholders' equity
Granted | shares	21,319
Warrants Outstanding at end of period (in shares) | shares	21,319
Granted | $ / shares	$ 1.0535
Outstanding at Period End | $ / shares	$ 1.0535
Granted, Wtd. Avg. Remaining Life (in years)	4 years 11 months 26 days
Outstanding at Period End, Wtd. Avg. Remaining Life (in years)	4 years 11 months 26 days
Pre-Funded Warrants
Stockholders' equity
Granted | shares	4,499
Warrants Outstanding at end of period (in shares) | shares	4,499
Granted | $ / shares	$ 0.0001
Outstanding at Period End | $ / shares	$ 0.0001

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Equity - 2021 Equity Incentive Plan (Details) - 2021 Plan - shares shares in Thousands	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Share-based compensation
Maximum number of shares that may be issued as a proportion of outstanding stock	10.00%
Maximum increase in number of shares available for issuance	400
Increase in share reserve	66
Outstanding options and restricted stock units	3,425	3,430
Reserved but unissued shares under the Plan	1,776	2,302
Total authorized shares under the Plan	5,201	5,732

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Equity - Equity Incentive Plan Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Share-based compensation
Outstanding shares, beginning balance			2,759
Forfeited/Expired (in shares)			(102)
Outstanding shares, ending balance	2,657		2,657		2,759
Exercisable (in shares)	1,947		1,947
Outstanding - Weighted Average Exercise Price (in dollars per share)			$ 2.07
Forfeited/Expired - Weighted Average Exercise Price (in dollars per share)			0.88
Outstanding - Weighted Average Exercise Price (in dollars per share)	$ 2.11		2.11		$ 2.07
Exercisable - Weighted Average Exercise Price (in dollars per share)	$ 1.75		$ 1.75
Stock options, Contractual life (in years)			4 years 9 months 29 days		5 years 4 months 17 days
Exercisable - Weighted Average Remaining Contractual Life (in years)			4 years 4 months 24 days
Compensation expense	$ 27	$ 15	$ 369	$ 225
Estimated aggregate pretax intrinsic value	21		21
Total unrecognized compensation	315		315
Equity Incentive Plan
Share-based compensation
Compensation expense	$ 37	$ 42	$ 87	$ 132

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Equity - Inducement Options (Details) - Non-Qualified Stock Option $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($)	Dec. 31, 2023	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($) installment $ / shares shares	Dec. 31, 2023 USD ($) installment $ / shares shares
Chief Technology Officer
Share-based compensation
Grants of stock options | shares						150
Exercise price (in dollars per share) | $ / shares						$ 0.91
Number of installments | installment						3
Vesting percentage						0.33%
Fair value of options granted (in dollars)						$ 112
Share based compensation cost related to vesting awards	$ 9		$ 0	$ 28	$ 0
Director of Customer Relationships and Business Development
Share-based compensation
Grants of stock options | shares					150
Exercise price (in dollars per share) | $ / shares					$ 1.31
Number of installments | installment					3
Vesting percentage					33.30%
Fair value of options granted (in dollars)					$ 160
Share based compensation cost related to vesting awards			$ 62		$ 62
Percentage of Inducement options forfeited		66.00%

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Equity - Restricted Stock Units (Details) - Restricted Stock Units - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Director
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Target value of compensation per quarter	$ 79
Unrecognized compensation expense for director services	501
Share-Based Payment Arrangement, Employee [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Reserve for share-based compensation tax withholdings	$ 38	$ 15

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Equity - Restricted Stock units Activity (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Number of Shares
Nonvested at beginning of year | shares	671
Granted | shares	420
Vested | shares	(323)
Nonvested at end of period | shares	768
Weighted Average Grant Date Fair Value
Nonvested at beginning of year | $ / shares	$ 1.05
Granted | $ / shares	1.00
Vested | $ / shares	1.08
Nonvested at end of period | $ / shares	$ 1.01

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Equity - Restricted Stock Units - Compensation Expense (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Equity
Compensation Expense	$ 27	$ 15	$ 369	$ 225
Weighted Average Value Per Share	$ 0.93	$ 0.80	$ 1.29	$ 0.80

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Equity - Stock Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based compensation
Weighted Average Value Per Share	$ 0.93	$ 0.80	$ 1.29	$ 0.80
Employee compensation in lieu of bonus
Share-based compensation
Fair value			$ 326	$ 234
Weighted Average Value Per Share			$ 1.06	$ 0.79
Shares issued	0	0

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Equity - Consultant Stock Plan (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Compensation Expense	$ 27	$ 15	$ 369	$ 225
Weighted Average Value Per Share	$ 0.93	$ 0.80	$ 1.29	$ 0.80
Consultant Stock Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum increase in available number of authorized shares as a percentage of new shares issued			1.00%
Reserved but unissued shares at beginning of year			188
Increases in the number of authorized shares			115
Grants			(36)
Reserved but unissued shares at end of year	267		267
Compensation Expense	$ 20	$ 2	$ 26	$ 7
Weighted Average Value Per Share	$ 0.72	$ 0.66	$ 0.74	$ 0.66
Equity Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Compensation Expense	$ 37	$ 42	$ 87	$ 132

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Net Loss Per Common Share (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net Loss Per Common Share
Shares excluded from calculation (in shares)	25,235	3,958
Employee Stock Option
Net Loss Per Common Share
Shares excluded from calculation (in shares)	3,148	3,250
Restricted Stock Units
Net Loss Per Common Share
Shares excluded from calculation (in shares)	768	708
Warrants
Net Loss Per Common Share
Shares excluded from calculation (in shares)	21,319

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Government Assistance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Research Grant From the Department of Energy
Government Assistance [Line Items]
Total award					$ 1,600	$ 250
Duration of the program					2 years
Government assistance	$ 116	$ 26	$ 332	$ 95
Oklahoma Quality Jobs Act
Government Assistance [Line Items]
Duration of the program							10 years
Government assistance	$ 17	$ 12	$ 64	$ 51