Note 2 - Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2022

Notes to Financial Statements

Significant Accounting Policies [Text Block]

2.     Summary of Significant Accounting Policies

Restricted cash and cash equivalents

Restricted cash as of June 30, 2021 represent funds that are restricted to satisfy any amount borrowed against the Company's Cash Collateral Security agreement with BMO Harris Bank N.A (Cash Collateral Security agreement). In June 2022, the Company replaced the former Cash Collateral Security agreement with an Investment Collateral Security agreement with BMO Harris Bank N.A (Investment Collateral Security agreement) where existing standby letters of credit are collateralized by amounts held in the Company's investment funds (see Note 10). At June 30, 2022, the amount of funds collateralized under the Investment Collateral Security agreement is $1,990 relating to existing standby letters of credit with varying maturity dates and expire no later than June 30, 2023.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash and cash equivalents reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows:

	June 30,		June 30,
	2022		2021
Cash	$	23,298	$	36,194
Cash equivalents		8,010		—
Restricted cash and cash equivalents included in current assets		1,990		98
Restricted cash included in long-term assets		—		270
Total cash, cash equivalents, and restricted cash and cash equivalents shown in the Condensed Consolidated Statements of Cash Flows	$	33,298	$	36,562

Investments

In June 2022, the Board of Directors approved a plan to invest up to $10 million of excess capital in debt securities, or held in money market funds until such investments can be made, with BMO Harris Bank N.A (BMO Harris). At June 30, 2022, $10,000 was invested in a money market fund with the intent to purchase debt securities in the near term. A portion of the funds invested are restricted as collateral under the Investment Collateral Security agreement (see Note 10). 

We consider all highly liquid debt investments with original maturities from the date of purchase of three months or less as cash equivalents. Cash equivalents include investments in money market funds. Carrying value of cash equivalents approximates fair value due to the maturities of 3 months or less.

Our investments in debt securities consist of Unites States (US) Treasury securities, including Notes, Bonds, and Bills, and US Government Agency securities, that are designated as held-to-maturity (HTM) and stated at amortized cost. The Company has the positive intent and ability to hold these investments to maturity and does not expect to sell any debt securities before maturity to settle an obligation under the Investment Collateral Security agreement. The maturities of our HTM investments range from 3 to 36 months. HTM debt investments with original maturities of approximately three months or less from the date of purchase are classified within cash and cash equivalents. HTM debt investments with original maturities at the date of purchase greater than approximately three months and remaining maturities of less than one year are classified as short-term investments. HTM debt investments with remaining maturities beyond one year are classified as other long-term investments. Interest income, including amortization of premium and accretion of discount, are included on the Condensed Consolidated Statements of Operations in Interest income under the effective yield method. Discounts or premiums are included in the effective yield and amortized on a straight-line until maturity.

Inventories

Inventories consist primarily of equipment constructed for resale and spare parts and are stated at the lower of cost or net realizable value, using the weighted-average cost method. At  June 30, 2022 and December 31, 2021, inventory included equipment constructed for resale of $208 and $227, respectively, and spare parts, net of reserves of $197 and $121, respectively. Usage is recorded in cost of sales in the period that parts were issued to a project, used to service equipment, or sold to customers. Inventories are periodically evaluated to identify obsolete or otherwise impaired parts and are written off when management determines usage is not probable. The Company estimates the balance of excess and obsolete inventory by analyzing inventory by age using last used and original purchase date and existing sales pipeline for which the inventory could be used.