Nature of Business and Basis of Presentation	6 Months Ended
Apr. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	Note 1. Nature of Business and Basis of Presentation FuelCell Energy, Inc., together with its subsidiaries (the “Company”, “FuelCell Energy”, “we”, “us”, or “our”) is a leading integrated fuel cell company with a growing global presence. We design, manufacture, install, operate and service ultra-clean, efficient and reliable stationary fuel cell power plants. Our SureSource power plants generate electricity and usable high quality heat for commercial, industrial, government and utility customers. We have commercialized our stationary carbonate fuel cells and are also pursuing the complementary development of planar solid oxide fuel cells and other fuel cell technologies. Our operations are funded primarily through sales of equity instruments to strategic investors or in public markets, corporate and project level debt financing and local or state government loans or grants. In order to produce positive cash flow from operations, we need to be successful at increasing annual order volume and production and in our cost reduction efforts. Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, they do not contain all of the information and footnotes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements. In the opinion of management, all normal and recurring adjustments necessary to fairly present the Company’s financial position and results of operations as of and for the three and six months ended April 30, 2019 and 2018 have been included. All intercompany accounts and transactions have been eliminated. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted. The balance sheet as of October 31, 2018 has been derived from the audited financial statements at that date, but it does not include all of the information and footnotes required by GAAP for complete financial statements. These financial statements should be read in conjunction with the Company’s financial statements and notes thereto for the fiscal year ended October 31, 2018, which are contained in the Company’s Annual Report on Form 10-K previously filed with the SEC. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year. On May 8, 2019 at 5:00 p.m. Eastern time, the Company effected a 1-for-12 reverse stock split, reducing the number of the Company’s common shares outstanding on that date from 183,411,230 shares to 15,284,269 shares. The number of authorized shares of common stock remains unchanged at 225,000,000 shares and the number of authorized shares of preferred stock remains unchanged at 250,000 shares. Additionally, the conversion rate of our Series B Preferred Stock (as defined elsewhere herein), the conversion price of our Series C Preferred Stock and Series D Preferred Stock (each as defined elsewhere herein), the exchange price of our Series 1 Preferred Shares (as defined elsewhere herein), the exercise price of all outstanding options and warrants, and the number of shares reserved for future issuance pursuant to our equity compensation plans were all adjusted proportionately in connection with the reverse stock split. All share and per share amounts and conversion prices presented herein have been adjusted retroactively to reflect these changes. Certain reclassifications have been made to the prior year amounts to conform to the current year presentation. The Company adopted Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers (Topic 606)" effective November 1, 2018 and applied the modified retrospective transition method. As a result of the adoption of this ASU, Unbilled receivables has been reclassified as a separate line item from Accounts receivable, net on the Consolidated Balance Sheets and Unbilled receivables has been classified as a separate item from Accounts receivable, net in the Consolidated Statement of Cash Flows for the prior year period. Going Concern and Liquidity Considerations The Company’s consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. The Company has significant short-term debt and other obligations currently due or maturing in less than one year, which are in excess of the Company’s cash and current asset balance, and the Company has been delaying certain payments to conserve cash. The Company has entered into a series of amendments to its senior secured debt facility with its senior lender Hercules Capital, Inc. (“Hercules”) in order to, among other things, provide for a lower minimum cash covenant and avoid events of default and acceleration of amounts due under the loan agreement. Most recently, Hercules provided an amendment through August 9, 2019. In exchange for this new amendment, the Company has agreed to pay down a portion of the outstanding principal amount in June 2019 as described below. The Company also has entered into amendments of its loan facility with NRG Energy Inc. (“NRG”) in order to extend the maturity date of the loan to July 12, 2019 as described below. As of April 30, 2019, the Company had an accumulated deficit from recurring net losses for the current and prior years. These factors as well as negative cash flows from operating and investing activities and negative working capital raise substantial doubt about the Company’s ability to continue as a going concern. Management has plans to address the Company’s current liquidity positon. These plans include exploring refinancing alternatives for the Company’s senior secured credit facility with Hercules. However, the Company may not be able to obtain such refinancing on acceptable terms, or at all. If the Company is not able to consummate such a refinancing transaction by August 9, 2019, and if Hercules is not willing to provide further accommodations, the Company could default on its obligations under its senior secured credit facility with Hercules. The occurrence of an event of default under the Hercules Agreement also constitute or may result in an event of default under, and cause or may cause the acceleration of, a number of material financial obligations including the State of Connecticut loan, the Connecticut Green Bank Loan and the Generate Lending, PNC and Fifth Third project finance facilities. The occurrence of an event of default under the Hercules Agreement also constitute a triggering event under the Series D Certificate of Designations. The Company also has obtained an amendment of the loan agreement with NRG that has a maturity date of July 12, 2019. Management plans to continue to pursue project financing for the Company’s generation backlog. If the Company is unable to obtain such project financing, it may have events of default under its project finance agreements, which are further described in Note 15, “Debt and Financing Obligation.” Other plans include implementing cost reduction measures such as the reduction in force implemented in April, increasing sales activity related to the Company’s products, and negotiating and entering into advanced technology research and development contracts. The Company may also consider licensing certain of its technology, sales of intellectual property and other assets, and/or sales of common stock directly to investors or through the Company’s at-the-market sales plan (which is subject to contractual requirements, trading windows and market conditions) to raise capital in the future. Subsequent to the end of the quarter ended April 30, 2019, the Company entered into a License Agreement (“EMRE License Agreement”) with ExxonMobil Research and Engineering Company (“EMRE”) for which the Company received a one-time payment of $10.0 million (of which $6.0 million was remitted to Hercules and applied as principal under the amendment referenced above). Refer to Note 18, “Subsequent Events” for further information regarding the EMRE License Agreement. The terms of any financing and other measures to obtain funds that may be undertaken by the Company may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development efforts and commercialization efforts and sell intellectual property and other assets, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. If the Company is unable to obtain external financing, it may not be able to sustain future operations. As a result, the Company may be required to delay, reduce and/or cease its operations and/or seek bankruptcy protection. Based on its recurring losses from operations, expectation of continuing operating losses for the foreseeable future, negative working capital, and need to raise additional capital to finance its future operations, the Company has concluded that there is substantial doubt about its ability to continue as a going concern for a period of one year after the date of filing of this Quarterly Report on Form 10-Q. The Company’s financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Use of Estimates The preparation of financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent liabilities. Estimates are used in accounting for, among other things, revenue recognition, contract loss accruals, excess, slow-moving and obsolete inventories, product warranty accruals, loss accruals on service agreements, share-based compensation expense, allowance for doubtful accounts, depreciation and amortization, impairment of goodwill and in-process research and development intangible assets, impairment of long-lived assets (including project assets), income taxes and contingencies. Estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the consolidated financial statements in the period they are determined to be necessary. Due to the inherent uncertainty involved in making estimates, actual results in future periods may differ from those estimates.

Nature of Business and Basis of Presentation

6 Months Ended

Apr. 30, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of Business and Basis of Presentation

Note 1. Nature of Business and Basis of Presentation

FuelCell Energy, Inc., together with its subsidiaries (the “Company”, “FuelCell Energy”, “we”, “us”, or “our”) is a leading integrated fuel cell company with a growing global presence. We design, manufacture, install, operate and service ultra-clean, efficient and reliable stationary fuel cell power plants. Our SureSource power plants generate electricity and usable high quality heat for commercial, industrial, government and utility customers. We have commercialized our stationary carbonate fuel cells and are also pursuing the complementary development of planar solid oxide fuel cells and other fuel cell technologies. Our operations are funded primarily through sales of equity instruments to strategic investors or in public markets, corporate and project level debt financing and local or state government loans or grants. In order to produce positive cash flow from operations, we need to be successful at increasing annual order volume and production and in our cost reduction efforts.

Basis of Presentation

The accompanying unaudited consolidated financial statements have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, they do not contain all of the information and footnotes required by accounting principles generally accepted in the United States of America (“GAAP”) for complete financial statements. In the opinion of management, all normal and recurring adjustments necessary to fairly present the Company’s financial position and results of operations as of and for the three and six months ended April 30, 2019 and 2018 have been included. All intercompany accounts and transactions have been eliminated.

Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted. The balance sheet as of October 31, 2018 has been derived from the audited financial statements at that date, but it does not include all of the information and footnotes required by GAAP for complete financial statements. These financial statements should be read in conjunction with the Company’s financial statements and notes thereto for the fiscal year ended October 31, 2018, which are contained in the Company’s Annual Report on Form 10-K previously filed with the SEC. The results of operations for the interim periods presented are not necessarily indicative of results that may be expected for any other interim period or for the full fiscal year.

On May 8, 2019 at 5:00 p.m. Eastern time, the Company effected a 1-for-12 reverse stock split, reducing the number of the Company’s common shares outstanding on that date from 183,411,230 shares to 15,284,269 shares. The number of authorized shares of common stock remains unchanged at 225,000,000 shares and the number of authorized shares of preferred stock remains unchanged at 250,000 shares. Additionally, the conversion rate of our Series B Preferred Stock (as defined elsewhere herein), the conversion price of our Series C Preferred Stock and Series D Preferred Stock (each as defined elsewhere herein), the exchange price of our Series 1 Preferred Shares (as defined elsewhere herein), the exercise price of all outstanding options and warrants, and the number of shares reserved for future issuance pursuant to our equity compensation plans were all adjusted proportionately in connection with the reverse stock split. All share and per share amounts and conversion prices presented herein have been adjusted retroactively to reflect these changes.

Certain reclassifications have been made to the prior year amounts to conform to the current year presentation. The Company adopted Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers (Topic 606)" effective November 1, 2018 and applied the modified retrospective transition method. As a result of the adoption of this ASU, Unbilled receivables has been reclassified as a separate line item from Accounts receivable, net on the Consolidated Balance Sheets and Unbilled receivables has been classified as a separate item from Accounts receivable, net in the Consolidated Statement of Cash Flows for the prior year period.

Going Concern and Liquidity Considerations

The Company’s consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. The Company has significant short-term debt and other obligations currently due or maturing in less than one year, which are in excess of the Company’s cash and current asset balance, and the Company has been delaying certain payments to conserve cash. The Company has entered into a series of amendments to its senior secured debt facility with its senior lender Hercules Capital, Inc. (“Hercules”) in order to, among other things, provide for a lower minimum cash covenant and avoid events of default and acceleration of amounts due under the loan agreement. Most recently, Hercules provided an amendment through August 9, 2019. In exchange for this new amendment, the Company has agreed to pay down a portion of the outstanding principal amount in June 2019 as described below. The Company also has entered into amendments of its loan facility with NRG Energy Inc. (“NRG”) in order to extend the maturity date of the loan to July 12, 2019 as described below. As of April 30, 2019, the Company had an accumulated deficit from recurring net losses for the current and prior years. These factors as well as negative cash flows from operating and investing activities and negative working capital raise substantial doubt about the Company’s ability to continue as a going concern.

Management has plans to address the Company’s current liquidity positon. These plans include exploring refinancing alternatives for the Company’s senior secured credit facility with Hercules. However, the Company may not be able to obtain such refinancing on acceptable terms, or at all. If the Company is not able to consummate such a refinancing transaction by August 9, 2019, and if Hercules is not willing to provide further accommodations, the Company could default on its obligations under its senior secured credit facility with Hercules. The occurrence of an event of default under the Hercules Agreement also constitute or may result in an event of default under, and cause or may cause the acceleration of, a number of material financial obligations including the State of Connecticut loan, the Connecticut Green Bank Loan and the Generate Lending, PNC and Fifth Third project finance facilities. The occurrence of an event of default under the Hercules Agreement also constitute a triggering event under the Series D Certificate of Designations. The Company also has obtained an amendment of the loan agreement with NRG that has a maturity date of July 12, 2019. Management plans to continue to pursue project financing for the Company’s generation backlog. If the Company is unable to obtain such project financing, it may have events of default under its project finance agreements, which are further described in Note 15, “Debt and Financing Obligation.” Other plans include implementing cost reduction measures such as the reduction in force implemented in April, increasing sales activity related to the Company’s products, and negotiating and entering into advanced technology research and development contracts. The Company may also consider licensing certain of its technology, sales of intellectual property and other assets, and/or sales of common stock directly to investors or through the Company’s at-the-market sales plan (which is subject to contractual requirements, trading windows and market conditions) to raise capital in the future. Subsequent to the end of the quarter ended April 30, 2019, the Company entered into a License Agreement (“EMRE License Agreement”) with ExxonMobil Research and Engineering Company (“EMRE”) for which the Company received a one-time payment of $10.0 million (of which $6.0 million was remitted to Hercules and applied as principal under the amendment referenced above). Refer to Note 18, “Subsequent Events” for further information regarding the EMRE License Agreement.

The terms of any financing and other measures to obtain funds that may be undertaken by the Company may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development efforts and commercialization efforts and sell intellectual property and other assets, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. If the Company is unable to obtain external financing, it may not be able to sustain future operations. As a result, the Company may be required to delay, reduce and/or cease its operations and/or seek bankruptcy protection. Based on its recurring losses from operations, expectation of continuing operating losses for the foreseeable future, negative working capital, and need to raise additional capital to finance its future operations, the Company has concluded that there is substantial doubt about its ability to continue as a going concern for a period of one year after the date of filing of this Quarterly Report on Form 10-Q.

The Company’s financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the financial statements have been prepared on a basis that assumes the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Use of Estimates

The preparation of financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent liabilities. Estimates are used in accounting for, among other things, revenue recognition, contract loss accruals, excess, slow-moving and obsolete inventories, product warranty accruals, loss accruals on service agreements, share-based compensation expense, allowance for doubtful accounts, depreciation and amortization, impairment of goodwill and in-process research and development intangible assets, impairment of long-lived assets (including project assets), income taxes and contingencies. Estimates and assumptions are reviewed periodically, and the effects of revisions are reflected in the consolidated financial statements in the period they are determined to be necessary. Due to the inherent uncertainty involved in making estimates, actual results in future periods may differ from those estimates.