FuelCell Energy (FCEL) 10-Q 8 Jun 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Apr. 30, 2023	Jun. 02, 2023
Cover [Abstract]
Entity Registrant Name	FUELCELL ENERGY, INC.
Entity Central Index Key	0000886128
Document Type	10-Q
Document Period End Date	Apr. 30, 2023
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	FCEL
Title of 12(b) Security	Common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Current Fiscal Year End Date	--10-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	1-14204
Entity Tax Identification Number	06-0853042
Entity Common Stock, Shares Outstanding		406,760,629
Entity Address, State or Province	CT
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Address, Address Line One	3 Great Pasture Road
Entity Address, City or Town	Danbury
Entity Address, Postal Zip Code	06810
City Area Code	203
Local Phone Number	825-6000
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	DE

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Current assets:
Cash and cash equivalents, unrestricted	$ 246,844	$ 458,055
Restricted cash and cash equivalents - short-term	4,778	4,423
Investments - short-term	76,400
Accounts receivable, net	6,447	4,885
Unbilled receivables	16,300	11,019
Inventories	87,294	90,909
Other current assets	14,452	10,989
Total current assets	452,515	580,280
Restricted cash and cash equivalents - long-term	25,452	18,566
Inventories - long-term	7,549	7,549
Project assets, net	237,151	232,886
Property, plant and equipment, net	71,130	58,137
Operating lease right-of-use assets, net	8,917	7,189
Goodwill	4,075	4,075
Intangible assets, net	16,725	17,373
Other assets	35,127	13,662
Total assets (1)	858,641	939,717
Current liabilities:
Current portion of long-term debt	13,289	13,198
Current portion of operating lease liabilities	645	650
Accounts payable	21,075	28,196
Accrued liabilities	22,873	27,415
Deferred revenue	4,782	16,341
Total current liabilities	62,664	85,800
Long-term deferred revenue and customer deposits		9,095
Long-term operating lease liabilities	9,392	7,575
Long-term debt and other liabilities	80,503	82,863
Total liabilities (1)	152,559	185,333
Redeemable noncontrolling interest		3,030
Stockholders' equity:
Common stock ($0.0001 par value); 500,000,000 shares authorized as of April 30, 2023 and October 31, 2022; 406,738,713 and 405,562,988 shares issued and outstanding as of April 30, 2023 and October 31, 2022, respectively	41	41
Additional paid-in capital	2,100,724	2,094,076
Accumulated deficit	(1,460,898)	(1,407,973)
Accumulated other comprehensive loss	(1,456)	(1,752)
Treasury stock, Common, at cost (163,943 and 142,837 shares as of April 30, 2023 and October 31, 2022, respectively)	(923)	(855)
Deferred compensation	923	855
Total stockholder's equity	638,411	684,392
Noncontrolling interests	7,814	7,105
Total equity	646,225	691,497
Total liabilities, redeemable Series B preferred stock, redeemable noncontrolling interest and total equity	858,641	939,717
Series B Preferred Stock
Current liabilities:
Redeemable Series B preferred stock (liquidation preference of $64,020 as of April 30, 2023 and October 31, 2022)	$ 59,857	$ 59,857

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	406,738,713	405,562,988
Common stock, shares outstanding	406,738,713	405,562,988
Treasury stock, shares	163,943	142,837
Assets	$ 858,641	$ 939,717
Cash	246,844	458,055
Accounts receivable, net	6,447	4,885
Unbilled receivables	16,300	11,019
Operating lease right-of-use assets, net	8,917	7,189
Other current assets	14,452	10,989
Restricted cash and cash equivalents - long-term	25,452	18,566
Project assets, net	237,151	232,886
Current portion of operating lease liabilities	645	650
Accounts payable	21,075	28,196
Accrued liabilities	22,873	27,415
Long-term operating lease liabilities	9,392	7,575
Other non-current liabilities	80,503	82,863
Total liabilities	152,559	185,333
Variable interest entity ("VIE")
Assets	124,338	119,223
Cash	2,814	2,149
Unbilled receivables	1,285	1,070
Operating lease right-of-use assets, net	1,178	1,184
Other current assets	20,670	14,373
Restricted cash and cash equivalents - long-term	500
Project assets, net	97,891	100,448
Current portion of operating lease liabilities	157	157
Accounts payable	85,637	76,050
Accrued liabilities		824
Long-term operating lease liabilities	1,476	1,478
Other non-current liabilities	179
Series B Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 64,020	$ 64,020

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022
Revenues:
Total revenues	$ 38,349	$ 16,384	$ 75,422	$ 48,179
Costs of revenues:
Total costs of revenues	44,442	23,694	76,278	58,384
Gross loss	(6,093)	(7,310)	(856)	(10,205)
Operating expenses:
Administrative and selling expenses	15,068	13,234	30,077	50,199
Research and development expenses	14,697	7,673	27,380	12,657
Total costs and expenses	29,765	20,907	57,457	62,856
Loss from operations	(35,858)	(28,217)	(58,313)	(73,061)
Interest expense	(1,502)	(1,707)	(3,014)	(3,135)
Interest income	3,688	84	7,098	94
Other expense, net	(236)	(286)	(187)	(144)
Loss before provision for income taxes	(33,908)	(30,126)	(54,416)	(76,246)
Provision for income taxes	(3)		(581)
Net loss	(33,911)	(30,126)	(54,997)	(76,246)
Net income (loss) attributable to noncontrolling interests	392	91	(2,072)	(5,405)
Net loss attributable to FuelCell Energy, Inc.	(34,303)	(30,217)	(52,925)	(70,841)
Series B preferred stock dividends	(800)	(800)	(1,600)	(1,600)
Net loss attributable to common stockholders	$ (35,103)	$ (31,017)	$ (54,525)	$ (72,441)
Loss per share basic and diluted:
Net loss per share attributable to common stockholders, basic	$ (0.09)	$ (0.08)	$ (0.13)	$ (0.20)
Net loss per share attributable to common stockholders, diluted	$ (0.09)	$ (0.08)	$ (0.13)	$ (0.20)
Basic weighted average shares outstanding	406,316,070	372,615,824	406,055,027	369,626,543
Diluted weighted average shares outstanding	406,316,070	372,615,824	406,055,027	369,626,543
Net loss	$ (33,911)	$ (30,126)	$ (54,997)	$ (76,246)
Other comprehensive income (loss):
Foreign currency translation adjustments	(151)	(149)	296	(240)
Total comprehensive loss	(34,062)	(30,275)	(54,701)	(76,486)
Comprehensive income attributable to noncontrolling interest	392	91	(2,072)	(5,405)
Comprehensive loss attributable to FuelCell Energy, Inc.	(34,454)	(30,366)	(52,629)	(71,081)
Series B Preferred Stock
Operating expenses:
Series B preferred stock dividends	(800)	(800)	(1,600)	(1,600)
Product
Revenues:
Total revenues			9,095	18,000
Costs of revenues:
Total costs of revenues	3,486	3,033	4,515	21,240
Service
Revenues:
Total revenues	26,190	2,639	40,072	4,806
Costs of revenues:
Total costs of revenues	20,113	3,033	31,058	5,405
Generation
Revenues:
Total revenues	8,440	9,050	17,997	16,546
Costs of revenues:
Total costs of revenues	17,081	14,120	33,683	24,842
Advanced Technologies
Revenues:
Total revenues	3,719	4,695	8,258	8,827
Costs of revenues:
Total costs of revenues	$ 3,762	$ 3,508	$ 7,022	$ 6,897

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total Stockholder's Equity [Member]	Common Stock	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Deferred Compensation [Member]	Noncontrolling Interests [Member]	Series B Preferred Stock	Total
Beginning Balance at Oct. 31, 2021	$ 642,438	$ 37	$ 1,908,471	$ (1,265,251)	$ (819)	$ (586)	$ 586			$ 642,438
Beginning Balance at (in shares) at Oct. 31, 2021		366,618,693
Common stock issued, non-employee compensation	100		100							100
Common stock issued, non-employee compensation (in shares)		20,673
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards	(260)		(260)							(260)
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards (in shares)		60,052
Share based compensation	1,470		1,470							1,470
Preferred dividends - Series B	(800)		(800)							(800)
Effect of foreign currency translation	(91)				(91)					(91)
Adjustment for deferred compensation						(64)	64
Adjustment for deferred compensation (in shares)		(13,232)
Net income (loss) attributable to redeemable noncontrolling interests	5,496			5,496				$ (5,496)
Net loss	(46,120)			(46,120)						(46,120)
Ending Balance at Jan. 31, 2022	602,233	$ 37	1,908,981	(1,305,875)	(910)	(650)	650	(5,496)		596,737
Ending Balance at (in shares) at Jan. 31, 2022		366,686,186
Beginning Balance at Oct. 31, 2021	642,438	$ 37	1,908,471	(1,265,251)	(819)	(586)	586			642,438
Beginning Balance at (in shares) at Oct. 31, 2021		366,618,693
Preferred dividends - Series B									$ (1,600)	(1,600)
Effect of foreign currency translation										(240)
Net loss attributable to noncontrolling interests										5,405
Net loss										(76,246)
Ending Balance at Apr. 30, 2022	691,094	$ 39	2,028,206	(1,336,092)	(1,059)	(718)	718	6,423		697,517
Ending Balance at (in shares) at Apr. 30, 2022		386,608,869
Beginning Balance at Jan. 31, 2022	602,233	$ 37	1,908,981	(1,305,875)	(910)	(650)	650	(5,496)		596,737
Beginning Balance at (in shares) at Jan. 31, 2022		366,686,186
Sale of common stock, net of fees	118,264	$ 2	118,262							118,264
Sale of common stock, net of fees (in shares)		19,896,904
Common stock issued, non-employee compensation	68		68							68
Common stock issued, non-employee compensation (in shares)		13,002
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards (in shares)		25,779
Share based compensation	1,695		1,695							1,695
Preferred dividends - Series B	(800)		(800)						(800)	(800)
Effect of foreign currency translation	(149)				(149)					(149)
Adjustment for deferred compensation						(68)	68
Adjustment for deferred compensation (in shares)		(13,002)
Reclass of redeemable non-controlling interest								12,419		12,419
Return of capital to distribution to noncontrolling interest								(496)		(496)
Distribution to noncontrolling interest								(95)		(95)
Net loss attributable to noncontrolling interests										(91)
Net income (loss) attributable to redeemable noncontrolling interests	(91)			(91)				91
Net loss	(30,126)			(30,126)						(30,126)
Ending Balance at Apr. 30, 2022	691,094	$ 39	2,028,206	(1,336,092)	(1,059)	(718)	718	6,423		697,517
Ending Balance at (in shares) at Apr. 30, 2022		386,608,869
Beginning Balance at Oct. 31, 2022	684,392	$ 41	2,094,076	(1,407,973)	(1,752)	(855)	855	7,105		$ 691,497
Beginning Balance at (in shares) at Oct. 31, 2022		405,562,988								405,562,988
Common stock issued, non-employee compensation	68		68							$ 68
Common stock issued, non-employee compensation (in shares)		21,106
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards	(314)		(314)							(314)
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards (in shares)		169,065
Share based compensation	2,637		2,637							2,637
Preferred dividends - Series B	(800)		(800)							(800)
Effect of foreign currency translation	447				447					447
Adjustment for deferred compensation						(68)	68
Adjustment for deferred compensation (in shares)		(21,106)
Reclass of redeemable non-controlling interest								3,030		3,030
Distribution to noncontrolling interest								(106)		(106)
Net loss attributable to noncontrolling interests	2,464			2,464				(2,464)
Net loss	(21,086)			(21,086)						(21,086)
Ending Balance at Jan. 31, 2023	667,808	$ 41	2,095,667	(1,426,595)	(1,305)	(923)	923	7,565		675,373
Ending Balance at (in shares) at Jan. 31, 2023		405,732,053
Beginning Balance at Oct. 31, 2022	684,392	$ 41	2,094,076	(1,407,973)	(1,752)	(855)	855	7,105		$ 691,497
Beginning Balance at (in shares) at Oct. 31, 2022		405,562,988								405,562,988
Preferred dividends - Series B									(1,600)	$ (1,600)
Effect of foreign currency translation										296
Net loss attributable to noncontrolling interests										2,072
Net loss										(54,997)
Ending Balance at Apr. 30, 2023	638,411	$ 41	2,100,724	(1,460,898)	(1,456)	(923)	923	7,814		$ 646,225
Ending Balance at (in shares) at Apr. 30, 2023		406,738,713								406,738,713
Beginning Balance at Jan. 31, 2023	667,808	$ 41	2,095,667	(1,426,595)	(1,305)	(923)	923	7,565		$ 675,373
Beginning Balance at (in shares) at Jan. 31, 2023		405,732,053
Sale of common stock, net of fees	2,663		2,663							2,663
Sale of common stock, net of fees (in shares)		949,438
Stock issued under benefit plans, net of taxes paid upon vesting of restricted stock awards (in shares)		57,222
Share based compensation	3,194		3,194							3,194
Preferred dividends - Series B	(800)		(800)						$ (800)	(800)
Effect of foreign currency translation	(151)				(151)					(151)
Distribution to noncontrolling interest								(143)		(143)
Net loss attributable to noncontrolling interests	(392)			(392)				392		(392)
Net loss	(33,911)			(33,911)						(33,911)
Ending Balance at Apr. 30, 2023	$ 638,411	$ 41	$ 2,100,724	$ (1,460,898)	$ (1,456)	$ (923)	$ 923	$ 7,814		$ 646,225
Ending Balance at (in shares) at Apr. 30, 2023		406,738,713								406,738,713

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Cash flows from operating activities:
Net loss	$ (54,997)	$ (76,246)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	5,831	3,165
Depreciation and amortization	12,036	11,103
Non-cash interest expense on finance obligations	2,071	2,099
Unrealized loss (gain) on derivitive contract	114	(523)
Operating lease costs	744	779
Operating lease payments	(644)	(730)
Impairment of property, plant and equipment and project assets	2,375	976
Unrealized foreign currency (gains) losses	(16)	578
Other, net	(36)	(134)
(Increase) decrease in operating assets:
Accounts receivable	(1,562)	(1,382)
Unbilled receivables	(21,164)	(242)
Inventories	3,615	(20,021)
Other assets	(10,577)	(6,154)
(Decrease) increase in operating liabilities:
Accounts payable	(1,486)	2,568
Accrued liabilities	(4,320)	8,057
Deferred revenue	(20,654)	11,400
Net cash used in operating activities	(88,670)	(64,707)
Cash flows from investing activities:
Capital expenditures	(16,903)	(10,395)
Project asset expenditures	(19,753)	(18,693)
Maturity of held-to-maturity debt securities	63,330
Purchases of held-to-maturity debt securities	(138,244)
Net cash used in investing activities	(111,570)	(29,088)
Cash flows from financing activities:
Repayment of debt	(4,528)	(4,857)
Expenses related to common stock issued for stock plans	21	26
Contributions received from sale of noncontrolling interest		12,419
Return of capital to noncontrolling interest		(496)
Distribution to noncontrolling interest	(249)	(95)
Payments for taxes related to net share settlement of equity awards	(337)	(286)
Common stock issuance, net of fees	2,667	118,264
Payment of preferred dividends	(1,600)	(1,600)
Net cash (used in) provided by financing activities	(4,026)	123,375
Effects on cash from changes in foreign currency rates	296	(240)
Net (decrease) increase in cash, cash equivalents and restricted cash	(203,970)	29,340
Cash, cash equivalents and restricted cash-beginning of period	481,044	460,212
Cash, cash equivalents and restricted cash-end of period	277,074	489,552
Supplemental cash flow disclosures:
Cash interest paid	663	815
Noncash financing and investing activity:
Recognition of operating lease liabilities	2,147
Recognition of operating lease right-of-use assets	2,147
Noncash reclassifications from inventory to project assets		4,217
Noncash reclassifications from other assets to project assets		2,375
Accrued purchase of fixed assets, cash to be paid in subsequent period	3,060	848
Accrued purchase of project assets, cash to be paid in subsequent period	$ 2,145	$ 5,085

Nature of Business and Basis of

Nature of Business and Basis of Presentation	6 Months Ended
	Apr. 30, 2023
Nature of Business and Basis of Presentation
Nature of Business and Basis of Presentation	Note 1. Nature of Business and Basis of Presentation Headquartered in Danbury, Connecticut, FuelCell Energy, Inc. (together with its subsidiaries, the “Company,” “FuelCell Energy,” “we,” “us,” or “our”) has leveraged five decades of research and development to become a global leader in delivering environmentally responsible distributed baseload power platform solutions through our proprietary fuel cell technology. Our current commercial technology produces electricity, heat, hydrogen, and water while separating carbon for utilization and/or sequestration. We continue to invest in developing and commercializing future technologies expected to add new capabilities to our platforms’ abilities to deliver hydrogen and long duration hydrogen-based energy storage through our solid oxide technologies, as well as further enhance our existing platforms’ carbon capture solutions. ​ FuelCell Energy is a global leader in sustainable clean energy technologies that address some of the world’s most critical challenges around energy access, security, safety and environmental stewardship. As a leading global manufacturer of proprietary fuel cell technology platforms, FuelCell Energy is uniquely positioned to serve customers worldwide with sustainable products and solutions for industrial and commercial businesses, utilities, governments, and municipalities. ​ 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, 2023 and 2022 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, 2022 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, 2022, 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. ​ Certain reclassifications have been made to the prior year amounts to conform to the presentation for the three and six months ended April 30, 2023. Interest income for the three and six months ended April 30, 2022, which was previously included within Other expense, net has been reclassified to Interest income in the Consolidated Statement of Operations and Comprehensive Loss. ​ Principles of Consolidation ​ The unaudited consolidated financial statements reflect our accounts and operations and those of our subsidiaries in which we have a controlling financial interest. We use a qualitative approach in assessing the consolidation requirement for each of our variable interest entities ("VIEs"), which are tax equity partnerships further described in Note 3. “Tax Equity Financings.” This approach focuses on determining whether we have the power to direct those activities of the tax equity partnerships that most significantly affect their economic performance and whether we have the obligation to absorb losses, or the right to receive benefits, that could potentially be significant to the tax equity partnerships. For all periods presented, we have determined that we are the primary beneficiary in all of our tax equity partnerships. We evaluate our tax equity partnerships on an ongoing basis to ensure that we continue to be the primary beneficiary. 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 assets and liabilities. Estimates are used in accounting for, among other things, revenue recognition, lease right-of-use assets and liabilities, 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), 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. Liquidity Our principal sources of cash have been proceeds from the sale of our products and projects, electricity generation revenues, research and development and service agreements with third parties, sales of our common stock through public equity offerings, and proceeds from debt, project financing and tax monetization transactions. We have utilized this cash to accelerate the commercialization of our solid oxide platforms, develop new capabilities to separate and capture carbon, develop and construct project assets, invest in capital improvements and expansion of our operations, perform research and development on Advanced Technologies, pay down existing outstanding indebtedness, and meet our other cash and liquidity needs. As of April 30, 2023, unrestricted cash and cash equivalents totaled $246.8 million compared to $458.1 million as of October 31, 2022. During the six months ended April 30, 2023, the Company invested $138.2 million in United States (U.S.) Treasury Securities and $63.3 million of the U.S. Treasury Securities matured. The amortized cost of the U.S. Treasury Securities outstanding as of April 30, 2023 totaled $76.4 million as of April 30, 2023 compared to $0 as of October 31, 2022 and is classified as Investments - short-term on the Consolidated Balance Sheets. The maturity dates for the outstanding U.S. Treasury Securities range from May 4, 2023 to October 5, 2023. On July 12, 2022, the Company entered into an Open Market Sale Agreement with Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canaccord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC (the “Open Market Sale Agreement”) with respect to an at the market offering program under which the Company may, from time to time, offer and sell up to 95.0 million shares of the Company’s common stock. From the date of the Open Market Sale Agreement through April 30, 2023, the Company sold approximately 19.4 million shares under the Open Market Sale Agreement at an average sale price of $3.60 per share, resulting in gross proceeds of approximately $70.0 million before deducting sales commissions and fees. During the three and six months ended April 30, 2023, approximately 0.9 million shares were sold under the Open Market Sale Agreement at an average sale price of $3.02 per share, resulting in gross proceeds of approximately $2.9 million. As of April 30, 2023, approximately 75.6 million shares were available for issuance under the Open Market Sale Agreement. The Company currently intends to use the net proceeds from this offering to accelerate the development and commercialization of its product platforms (including, but not limited to, its solid oxide and carbon capture platforms), for project development, market development, and internal research and development, to invest in capacity expansion for solid oxide and carbonate fuel cell manufacturing, and for project financing, working capital support, and general corporate purposes. The Company may also use the net proceeds from this offering to invest in joint ventures, acquisitions, and strategic growth investments and to acquire, license or invest in products, technologies or businesses that complement its business. See Note 11. “Stockholders’ Equity” for additional information regarding the Open Market Sale Agreement. ​ We believe that our unrestricted cash and cash equivalents, expected receipts from our contracted backlog, funds received upon the maturity of U.S. Treasury Securities, and release of short-term restricted cash less expected disbursements over the next twelve months will be sufficient to allow the Company to meet its obligations for at least one year from the date of issuance of these financial statements. ​ To date, we have not achieved profitable operations or sustained positive cash flow from operations. The Company’s future liquidity, for fiscal year 2023 and in the long-term, will depend on its ability to (i) timely complete current projects in process within budget, (ii) increase cash flows from its generation operating portfolio, including by meeting conditions required to timely commence operation of new projects, operating its generation operating portfolio in compliance with minimum performance guarantees and operating its generation operating portfolio in accordance with revenue expectations, (iii) obtain financing for project construction and manufacturing expansion, (iv) obtain permanent financing for its projects once constructed, (v) increase order and contract volumes, which would lead to additional product sales, service agreements and generation revenues, (vi) obtain funding for and receive payment for research and development under current and future Advanced Technologies contracts, (vii) successfully commercialize its Advanced Technologies platforms, including its solid oxide, hydrogen and carbon capture platforms, (viii) implement capacity expansion for solid oxide product manufacturing, (ix) implement the product cost reductions necessary to achieve profitable operations, (x) manage working capital and the Company’s unrestricted cash balance and (xi) access the capital markets to raise funds through the sale of debt and equity securities, convertible notes, and other equity-linked instruments. We are continually assessing different means by which to accelerate the Company’s growth, enter new markets, commercialize new products, and enable capacity expansion. Therefore, from time to time, the Company may consider and enter into agreements for one or more of the following: negotiated financial transactions, minority investments, collaborative ventures, technology sharing, transfer or other technology license arrangements, joint ventures, partnerships, acquisitions or other business transactions for the purpose(s) of geographic or manufacturing expansion and/or new product or technology development and commercialization, including hydrogen production through our carbonate and solid oxide platforms and storage and carbon capture, sequestration and utilization technologies. Our business model requires substantial outside financing arrangements and satisfaction of the conditions of such arrangements to construct and deploy our projects to facilitate the growth of our business. The Company has invested capital raised from sales of its common stock to build out its project portfolio. The Company has also utilized and expects to continue to utilize a combination of long-term debt and tax equity financing (e.g., sale-leaseback transactions, partnership flip transactions and the monetization and/or transfer of eligible investment and production tax credits) to finance its project asset portfolio as these projects commence commercial operations, particularly in light of the passage of the Inflation Reduction Act in August 2022. The Company may also seek to undertake private placements of debt securities of a portfolio of assets to finance its project asset portfolio. The proceeds of any such financing, if obtained, may allow the Company to reinvest capital back into the business and to fund other projects. We may also seek to obtain additional financing in both the debt and equity markets in the future. If financing is not available to us on acceptable terms if and when needed, or on terms acceptable to us or our lenders, if we do not satisfy the conditions of our financing arrangements, if we spend more than the financing approved for projects, if project costs exceed an amount that the Company can finance, or if we do not generate sufficient revenues or obtain capital sufficient for our corporate needs, we may be required to reduce or slow planned spending, reduce staffing, sell assets, seek alternative financing and take other measures, any of which could have a material adverse effect on our financial condition and operations. ​ Subsequent to the end of quarter, the Company entered into a project financing facility and extinguished its then-outstanding indebtedness to Liberty Bank and Fifth Third Bank. In connection with the extinguishment of the Company’s indebtedness to Liberty Bank and Fifth Third Bank, approximately $11.2 million of restricted cash was released to the Company from Liberty Bank and Fifth Third Bank. Taking into consideration the release of such funds, the total net proceeds to the Company from the financing facility and related transactions were approximately $46.1 million, which will be classified as unrestricted cash on the Company’s Consolidated Balance Sheet. See Note 18. “Subsequent Events” for additional information. ​

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Apr. 30, 2023
Recent Accounting Pronouncements
Recent Accounting Pronouncements	Note 2. Recent Accounting Pronouncements Recently Adopted Accounting Guidance There is no recently adopted accounting guidance. Recent Accounting Guidance Not Yet Effective There is no recent accounting guidance that is not yet effective. ​

Tax Equity Financing

Tax Equity Financing	6 Months Ended
	Apr. 30, 2023
Tax Equity Financing.
Tax Equity Financing	Note 3. Tax Equity Financings ​ Groton Tax Equity Financing Transaction ​ The Company closed on a tax equity financing transaction in August 2021 with East West Bancorp, Inc. (“East West Bank”) for the 7.4 MW fuel cell project (the “Groton Project”) located on the U.S. Navy Submarine Base in Groton, CT. East West Bank’s tax equity commitment totals $15 million. ​ This transaction was structured as a “partnership flip”, which is a structure commonly used by tax equity investors in the financing of renewable energy projects. Under this partnership flip structure, a partnership, in this case Groton Station Fuel Cell Holdco, LLC (the “Groton Partnership”), was organized to acquire from FuelCell Energy Finance II, LLC, a wholly-owned subsidiary of the Company, all outstanding equity interests in Groton Station Fuel Cell, LLC (the “Groton Project Company”) which in turn owns the Groton Project and is the party to the power purchase agreement and all project agreements. At the closing of the transaction, the Groton Partnership is owned by East West Bank, holding Class A Units, and Fuel Cell Energy Finance Holdco, LLC, a subsidiary of FuelCell Energy Finance, LLC, holding Class B Units. The acquisition of the Groton Project Company by the Groton Partnership was funded in part by an initial draw from East West Bank and funds contributed downstream to the Groton Partnership by the Company. The initial closing occurred on August 4, 2021, upon the satisfaction of certain conditions precedent (including the receipt of an appraisal and confirmation that the Groton Project would be eligible for the investment tax credit under Section 48 of the Internal Revenue Code of 1986, as amended). In connection with the initial closing, the Company drew down $3.0 million, of which approximately $0.8 million was used to pay closing costs including appraisal fees, title insurance expenses and legal and consulting fees. Under the original terms of the Company’s agreement with East West Bank, the Company would have been eligible to draw the remaining amount of the commitment, approximately $12 million, once the Groton Project achieved commercial operation. In addition, under the original terms of the Company’s agreement with East West Bank, the Groton Project had a required commercial operations deadline of October 18, 2021. The significance of the commercial operations deadline is that, if commercial operations were not achieved by such deadline, East West Bank would have the option to require an amount equal to 101% of its investment to be returned. East West Bank granted several extensions of the commercial operations deadline, which collectively extended the deadline to May 15, 2022, in exchange for the Company’s agreement to pay fees of $0.4 million in the aggregate ​ On July 7, 2022, the Company and East West Bank amended their tax equity financing agreement and extended the commercial operations deadline to September 30, 2022. In addition, in the July 7, 2022 amendment to the tax equity financing agreement, the terms of East West Bank’s remaining investment commitment of $12.0 million were modified such that East West Bank will contribute $4.0 million on each of the first second third ​ On October 4, 2022, the Company and East West Bank further amended their tax equity financing agreement to extend the deadline by which commercial operations were to be achieved at the Groton Project from September 30, 2022 to November 30, 2022. In addition, modifications to the Groton Project documents between Connecticut Municipal Electric Energy Cooperative (“CMEEC”) and the Company as a result of the agreement between those parties to commence operations at less than 7.4 MW required the approval of East West Bank as part of East West Bank’s rights under the agreement between East West Bank and the Company. On December 16, 2022, the Company and CMEEC agreed that, for all purposes, the commercial operations date had occurred, and, accordingly, East West Bank no longer had a right to have its investment returned as a result of the Company’s failure to achieve commercial operations in a timely fashion, and this investment became a non-redeemable noncontrolling interest as of December 16, 2022. In addition, on December 16, 2022, the Company paid the aggregate fees of $0.5 million described above to East West Bank. ​ On December 16, 2022, the Company declared and, per the terms of the Amended and Restated Power Purchase Agreement between the Company and CMEEC entered into on that date (the “Amended and Restated PPA”), CMEEC agreed that the Groton Project is commercially operational at 6 MW. As of December 16, 2022, the Groton Project is reported as a part of the Company’s generation operating portfolio. The Amended and Restated PPA allows the Company to operate the plants at a reduced output of approximately 6 MW while a Technical Improvement Plan (“TIP”) is implemented over the next year with the goal of bringing the platform to its rated capacity of 7.4 MW by December 31, 2023. In conjunction with entering into the Amended and Restated PPA, the Navy also provided its authorization to proceed with commercial operations at 6 MW. The Company paid CMEEC an amendment fee of $1.2 million and is incurring and will continue to incur performance guarantee fees under the Amended and Restated PPA as a result of operating at an output below 7.4 MW during implementation of the TIP. Although the Company believes it will successfully implement the TIP and bring the plants up to their nominal output of 7.4 MW by December 31, 2023, no assurance can be provided that such work will be successful. In the event that the plants do not reach an output of 7.4 MW by December 31, 2023, the Amended and Restated PPA will continue in effect, and the Company will be subject to ongoing performance guarantee fees as set forth in the Amended and Restated PPA. ​ With the declaration of commercial operations, East West Bank’s investment in the project was reclassified, as of December 16, 2022, from a redeemable noncontrolling interest to non-redeemable noncontrolling interests within the Total equity section of the Consolidated Balance Sheet. ​ Under most partnership flip structures, tax equity investors agree to receive a minimum target rate of return, typically on an after-tax basis. Prior to receiving a contractual rate of return or a date specified in the contractual arrangements, East West Bank will receive substantially all of the non-cash value attributable to the Groton Project, which includes accelerated depreciation and Section 48(a) investment tax credits; however, the Company will receive a majority of the cash distributions (based on the operating income of the Groton Project), which are paid quarterly. After East West Bank receives its contractual rate of return, the Company will receive approximately 95% of the cash and tax allocations. The Company (through a separate wholly owned entity) may enter into a back leverage debt financing transaction and use the cash distributions from the Groton Partnership to service the debt. We have determined we are the primary beneficiary in the Groton Partnership for accounting purposes as a Variable Interest Entity (“VIE”) under GAAP. We have considered the provisions within the financing-related agreements (including the limited liability company agreement for the Groton Partnership) Consolidations . ​ Yaphank Tax Equity Financing Transaction ​ The Company closed on a tax equity financing transaction in November 2021 with Renewable Energy Investors, LLC (“REI”), a subsidiary of Franklin Park Infrastructure, LLC, for the 7.4 MW fuel cell project (the “LIPA Yaphank Project”) located in Yaphank Long Island. REI’s tax equity commitment totaled $12.4 million. ​ This transaction was structured as a “partnership flip,” which is a structure commonly used by tax equity investors in the financing of renewable energy projects. Under this partnership flip structure, a partnership, in this case YTBFC Holdco, LLC (the “Yaphank Partnership”), was organized to acquire from FuelCell Energy Finance II, LLC, a wholly-owned subsidiary of the Company, all outstanding equity interests in Yaphank Fuel Cell Park, LLC which in turn owns the LIPA Yaphank Project and is the party to the power purchase agreement and all project agreements. . ​ The Company determined during the second quarter of fiscal year 2022 that there was an overpayment by REI of the Class A Member Capital Contribution of $0.5 million and as such the Company refunded this amount back to REI, reducing the REI tax equity commitment to $11.9 million. During the six months ended April 30, 2023 and 2022, the Company made priority return distributions to REI of $0.2 million and $0.1 million, respectively. ​ Under a partnership flip structure, tax equity investors agree to receive a minimum target rate of return, typically on an after-tax basis. Prior to receiving a contractual rate of return or a date specified in the contractual arrangements, REI will receive substantially all of the non-cash value attributable to the LIPA Yaphank Project, which includes accelerated depreciation and Section 48(a) investment tax credits; however, the Company will receive a majority of the cash distributions (based on the operating income of the LIPA Yaphank Project), which are paid quarterly. After REI receives its contractual rate of return, the Company will receive approximately 95% of the cash and tax allocations. The Company may enter into a back leverage debt financing transaction and use the cash distributions from the Yaphank Partnership to service the debt. ​ Under this partnership flip structure, after the fifth anniversary following achievement of commercial operations, we have an option to acquire all of the equity interests that REI holds in the Yaphank Partnership starting after REI receives its contractual rate of return (the anticipated “flip” date) after the LIPA Yaphank Project is operational. If we exercise this option, we will be required to pay the greater of the following: (i) the fair market value of REI’s equity interest at the time the option is exercised or (ii) an amount equal to 10.3% of REI’s capital contributions. This option payment is to be grossed up for federal taxes if it exceeds the tax basis of the Yaphank Partnership Class A Units. We are the primary beneficiary in the Yaphank Partnership for accounting purposes as a VIE under GAAP. We have considered the provisions within the financing-related agreements (including the limited liability company agreement for the Yaphank Partnership) which grant us power to manage and make decisions affecting the operations of the Yaphank Partnership. We consider the rights granted to REI under the agreements to be more protective in nature rather than participatory. Therefore, we have determined under the power and benefits criterion of ASC 810, Consolidations .

Revenue Recognition

Revenue Recognition	6 Months Ended
	Apr. 30, 2023
Revenue Recognition
Revenue Recognition	​ Note 4. Revenue Recognition Revenue Recognition – Groton Project PPA The Groton Project Amended and Restated PPA that was entered into on December 16, 2022 (as discussed further in Note 3. “Tax Equity Financings”) has resulted in revenue recognition to be accounted for in accordance with ASC 606, “Revenue from Contracts with Customers,” whereas this PPA was previously recorded under ASC 842, “Leases.” The Company’s performance obligation is to provide 100% of the electricity output to the customer. The promise to provide electricity over the term of the PPA represents a single performance obligation, as it is a promise to transfer a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. Revenue is recognized over time as the customer simultaneously receives and consumes the benefits provided by the Company, and the Company satisfies its performance obligation. Revenue is recognized based on the output method as there is a directly observable output to the customer-electricity delivered to the customer and immediately consumed. Contract Balances Contract assets as of April 30, 2023 and October 31, 2022 were $41.9 million ($25.6 million long-term) and $20.7 million ($9.7 million long-term), respectively. The contract assets relate to the Company’s rights to consideration for work performed but not yet billed. These amounts are included on a separate line item as Unbilled receivables, and balances expected to be billed later than one year from the balance sheet date are included within Other assets on the accompanying Consolidated Balance Sheets. We bill customers for power platform and power platform component sales based on certain contractual milestones being reached. We bill service agreements and PPAs based on the contract price and billing terms of the contracts. Generally, our Advanced Technologies contracts are billed based on actual revenues recorded, typically in the subsequent month. Some Advanced Technologies contracts are billed based on contractual milestones or costs incurred. The net change in contract assets represents amounts recognized as revenue offset by customer billings. Contract liabilities as of April 30, 2023 and October 31, 2022 were $4.8 million and $25.4 million, respectively. The contract liabilities relate to the advance billings to customers for services that will be recognized over time. The net change in contract liabilities represents customer billings offset by revenue recognized. Contract modification ​ As previously disclosed, the Company entered into a Settlement Agreement (the “Settlement Agreement”) with POSCO Energy Co., Ltd. (“POSCO Energy”) and its subsidiary, Korea Fuel Cell Co., Ltd. (“KFC”), in fiscal year 2022. The Settlement Agreement included an option to purchase an additional 14 modules (in addition to the 20 modules which were purchased by KFC during fiscal year 2022). The option was not exercised as of the expiration date of December 31, 2022 and, as a result, the Company recognized $9.1 million of product revenue during the six months ended April 30, 2023 which represents the consideration allocated to the material right had the option been exercised. ​ Advanced Technologies Revenue – EMTEC Joint Development Agreement ​ On December 19, 2022, the Company and ExxonMobil Technology and Engineering Company (formerly known as ExxonMobil Research and Engineering Company) (“EMTEC”) entered into Amendment No. 3 to the Joint Development Agreement between the Company and EMTEC, effective as of December 1, 2022 (such amendment, “Amendment No. 3” and such agreement, as amended, the “EMTEC Joint Development Agreement”). In Amendment No. 3, the Company and EMTEC agreed to further extend the term of the EMTEC Joint Development Agreement such that it will end on August 31, 2023 (unless terminated earlier) and to further increase the maximum amount of contract consideration to be reimbursed by EMTEC from $50.0 million to $60.0 million. Amendment No. 3 is intended to (i) allow for continuation of research that would enable the parties to finalize data collection in support of the project gate decision to use the developed technology in a Company fuel cell module demonstration for capturing carbon at ExxonMobil’s Rotterdam facility, (ii) allow for the continuation of the development, engineering and mechanical derisking of the Generation 2 Technology fuel cell module prototype, and (iii) allow for studying the manufacturing scale-up and cost reduction of a commercial Generation 2 Technology fuel cell carbon capture facility. ​ During the six months ended April 30, 2022, the Company achieved the first technical milestone under the EMTEC Joint Development Agreement and received payment of $5.0 million. At the time, the Company did not recognize revenue in connection with this milestone achievement as a result of its agreement with EMTEC to either make a $5.0 million investment in a demonstration of a Company fuel cell module for capturing carbon at ExxonMobil’s Rotterdam refinery located in Rotterdam, Netherlands (the “ ​ Remaining Performance Obligations Remaining performance obligations are the aggregate amount of total contract transaction price that is unsatisfied or partially unsatisfied. As of April 30, 2023, the Company’s total remaining performance obligations were: $73.7 million for service agreements, $65.1 million for a generation PPA and $22.6 million for Advanced Technologies contracts in the aggregate. Service revenue in periods in which there are no module exchanges is expected to be relatively consistent from period to period, whereas module exchanges will result in an increase in revenue when exchanges occur.

Investments - Short-Term

Investments - Short-Term	6 Months Ended
	Apr. 30, 2023
Investments - Short-Term
Investments - Short-Term	Note 5. Investments – Short-Term During the six months ended April 30, 2023, the Company invested $138.2 million to purchase U.S. Treasury Securities. $63.3 million of the U.S. Treasury Securities matured during the six months ended April 30, 2023. The U.S. Treasury Securities outstanding as of April 30, 2023 have maturity dates ranging from May 4, 2023 to October 5, 2023. We have classified the U.S. Treasury Securities as held-to-maturity and recorded them at amortized cost. The following table summarizes the amortized cost basis and fair value (based on quoted market prices) at April 30, 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross unrealized ​ Gross unrealized ​ ​ cost gains ​ losses Fair value U.S. Treasury Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 30, 2023 ​ $ 76,400 $ - $ (17) $ 76,383 ​ The contractual maturities of investments are within one year and the weighted average yield to maturity is 4.75%.

Inventories

Inventories	6 Months Ended
	Apr. 30, 2023
Inventories
Inventories	Note 6. Inventories Inventories (current and long-term) as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Raw materials ​ $ 39,261 ​ $ 30,624 Work-in-process (1) ​ ​ 55,582 ​ ​ 67,834 Inventories ​ ​ 94,843 ​ ​ 98,458 Inventories – current ​ ​ (87,294) ​ ​ (90,909) Inventories – long-term (2) ​ $ 7,549 ​ $ 7,549 (1) Work-in-process includes the standard components of inventory used to build the typical modules or module components that are intended to be used in future project asset construction or power plant orders or for use under the Company’s service agreements. Included in work-in-process as of April 30, 2023 and October 31, 2022 was $35.2 million and $54.0 million, respectively, of completed standard components and modules. (2) Long-term inventory includes modules that are contractually required to be segregated for use as exchange modules for specific project assets. Raw materials consist mainly of various nickel powders and steels, various other components used in producing cell stacks and purchased components for balance of plant. Work-in-process inventory is comprised of material, labor, and overhead costs incurred to build fuel cell stacks and modules, which are subcomponents of a power platform.

Project Assets

Project Assets	6 Months Ended
	Apr. 30, 2023
Project Assets
Project Assets	Note 7. Project Assets Project assets as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ Estimated ​ 2023 2022 Useful Life Project Assets – Operating ​ $ 210,211 ​ $ 154,736 ​ 4-20 years Accumulated depreciation ​ ​ (36,081) ​ ​ (29,546) ​ ​ Project Assets – Operating, net ​ ​ 174,130 ​ ​ 125,190 ​ ​ Project Assets – Construction in progress ​ ​ 63,021 ​ ​ 107,696 ​ ​ Project Assets, net ​ $ 237,151 ​ $ 232,886 ​ ​ ​ The estimated useful lives of these project assets are 20 years for balance of plant (“BOP”) and site construction, and four Project assets as of April 30, 2023 and October 31, 2022 also include installations with carrying values of $63.0 million and $107.7 million, respectively, which are being developed and constructed by the Company in connection with projects for which we have entered into PPAs or projects for which we expect to secure PPAs or otherwise recover the asset value and which have not yet been placed in service. Included in “Construction in progress” is the 2.3 MW Toyota project. It was determined in the fourth quarter of fiscal year 2021 that a potential source of renewable natural gas (“RNG”) at favorable pricing was no longer sufficiently probable and that market pricing for RNG had significantly increased, resulting in the determination that the carrying value of the project asset was no longer recoverable. Refer to Note 17. “Commitments and Contingencies” for more information regarding fuel risk exposure. As this project is being constructed, only inventory components that can be redeployed for alternative use are being capitalized. The balance of costs incurred are being expensed as generation cost of revenues. Project construction costs incurred for long-term project assets are reported as investing activities in the Consolidated Statements of Cash Flows. The proceeds received from the sale and subsequent leaseback of project assets are classified as financing activities within the Consolidated Statements of Cash Flows and are classified as a finance obligation within “Current portion of long-term debt” and “Long-term debt and other liabilities” on the Consolidated Balance Sheets (refer to Note 15. “Debt” for more information).

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Apr. 30, 2023
Goodwill and Intangible Assets
Goodwill and Intangible Assets	Note 8. Goodwill and Intangible Assets As of April 30, 2023 and October 31, 2022, the Company had goodwill of $4.1 million and intangible assets of $16.7 million and $17.4 million, respectively, that were recorded in connection with the Company’s 2012 acquisition of Versa Power Systems, Inc. (“Versa”) and the 2019 Bridgeport Fuel Cell Project acquisition. The Versa acquisition intangible asset represents an indefinite-lived in-process research and development intangible asset (“IPR&D”) for cumulative research and development efforts associated with the development of solid oxide fuel cell stationary power generation. Amortization expense for the Bridgeport Fuel Cell Project-related intangible asset for each of the three month periods ended April 30, 2023 and 2022 was $0.3 million and for each of the six month periods ended April 30, 2023 and 2022 was $0.6 million. The following tables summarize the carrying value of the Company’s intangible assets as of April 30, 2023 and October 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 30, 2023 Gross Amount Accumulated Amortization Net Amount In-Process Research and Development ​ $ 9,592 ​ $ - ​ $ 9,592 Bridgeport PPA ​ ​ 12,320 ​ ​ (5,187) ​ ​ 7,133 Total ​ $ 21,912 ​ $ (5,187) ​ $ 16,725 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of October 31, 2022 Gross Amount Accumulated Amortization Net Amount In-Process Research and Development ​ $ 9,592 ​ $ - ​ $ 9,592 Bridgeport PPA ​ ​ 12,320 ​ ​ (4,539) ​ ​ 7,781 Total ​ $ 21,912 ​ $ (4,539) ​ $ 17,373 ​

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Apr. 30, 2023
Accrued Liabilities
Accrued Liabilities	Note 9. Accrued Liabilities Accrued liabilities as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Accrued payroll and employee benefits (1) ​ $ 6,482 ​ $ 8,534 Accrued product warranty cost ​ ​ 314 ​ ​ 537 Accrued service agreement and PPA costs (2) ​ ​ 12,580 ​ ​ 11,340 Accrued legal, taxes, professional and other ​ ​ 3,497 ​ ​ 7,004 Accrued liabilities ​ $ 22,873 ​ $ 27,415 (1) The balance in this account represents accrued payroll, payroll taxes and accrued bonus for both periods. The decrease in the account relates to a decrease in accrued bonus as of April 30, 2023 due to the payout in January 2023 of bonuses earned under the 2022 Management Incentive Plan. (2) Accrued service agreement costs include loss accruals on service agreements of $ 7.2 million and $7.3 million as of April 30, 2023 and October 31, 2022, respectively. The accruals for performance guarantees on service agreements and PPAs were $ 5.3 million and $4.1 million as of April 30, 2023 and October 31, 2022.

Leases

Leases	6 Months Ended
	Apr. 30, 2023
Leases
Leases	Note 10. Leases The Company enters into operating and finance lease agreements for the use of real estate, vehicles, information technology equipment, and certain other equipment. We determine if an arrangement contains a lease at inception, which is the date on which the terms of the contract are agreed to and the agreement creates enforceable rights and obligations. Operating leases are included in Operating lease right-of-use assets, net, Operating lease liabilities, and Long-term operating lease liabilities in the Company’s Consolidated Balance Sheets. Finance leases are not considered significant to the Company’s Consolidated Balance Sheets or Consolidated Statements of Operations and Comprehensive Loss. Finance lease right-of-use (“ROU”) assets of $0.04 million at April 30, 2023 and October 31, 2022 are included in Property, plant and equipment, net in the Company’s Consolidated Balance Sheets. Finance lease liabilities of $0.04 million at April 30, 2023 and October 31, 2022 are included in Current portion of long-term debt and Long-term debt and other liabilities in the Company’s Consolidated Balance Sheets. On January 5, 2023, the Company’s wholly-owned subsidiary, Versa Power Systems Ltd. (“Versa Ltd.”), entered in to a lease expansion, extension and amending agreement to an existing building lease that was originally entered into on May 20, 2005. The lease expansion, extension and amending agreement extended the term of the lease through September 30, 2028 and expanded the space to be leased by Versa Ltd. in Calgary, Alberta, Canada to include approximately 48,000 square feet of additional space. A ROU asset and operating lease liability was initially recorded for this lease as of the first quarter of fiscal year 2023 USD On February 20, 2023, Versa Ltd. entered into a Lease Expansion and Amending Agreement – Short Term (the “Lease Expansion and Amendment”) to the existing lease for the Calgary manufacturing facility (i.e., the lease referenced in the paragraph immediately above). Under the Lease Expansion and Amendment, the space leased by Versa Ltd. has been further expanded to include, on a short-term basis, an additional space located at the same address as the original Calgary manufacturing facility (4800 – 52 nd 2023 USD ​ Operating lease expense for each of the three month periods ended April 30, 2023 and 2022 was $0.4 million and for the six months ended April 30, 2023 and 2022 was $0.7 million and $0.8 million, respectively. As of April 30, 2023, the weighted average remaining lease term (in years) was approximately 17 years and the weighted average discount rate was 6.95%. Lease payments made during each of the three month periods ended April 30, 2023 and 2022 were $0.3 million and for the six months ended April 30, 2023 and 2022 were $0.6 million and $0.7 million, respectively. Undiscounted maturities of operating lease and finance lease liabilities as of April 30, 2023 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Due Year 1 ​ $ 1,185 ​ $ 41 Due Year 2 ​ ​ 1,353 ​ ​ — Due Year 3 ​ ​ 1,263 ​ ​ — Due Year 4 ​ ​ 1,294 ​ ​ — Due Year 5 ​ ​ 1,313 ​ ​ — Thereafter ​ ​ 13,303 ​ ​ — Total undiscounted lease payments ​ ​ 19,711 ​ ​ 41 Less imputed interest ​ ​ (9,674) ​ ​ (6) Total discounted lease payments ​ $ 10,037 ​ $ 35 ​

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Apr. 30, 2023
Stockholders' Equity
Stockholders' Equity	Note 11. Stockholders’ Equity 2022 Open Market Sale Agreement On July 12, 2022, the Company entered into an Open Market Sale Agreement with Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canaccord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC (the “Open Market Sale Agreement”) with respect to an at the market offering program under which the Company may, from time to time, offer and sell up to 95.0 million shares of the Company’s common stock. Pursuant to the Open Market Sale Agreement, the Company pays each agent a commission equal to 2.0% of the gross proceeds from each sale of shares made by such agent under the Open Market Sale Agreement. ​ As of April 30, 2023, approximately 75.6 million shares were available for issuance under the Open Market Sale Agreement.

Redeemable Preferred Stock

Redeemable Preferred Stock	6 Months Ended
	Apr. 30, 2023
Redeemable Preferred Stock
Redeemable Preferred Stock	Note 12. Redeemable Preferred Stock The Company is authorized to issue up to 250,000 shares of preferred stock, par value $0.01 per share, in one or more series, of which 105,875 shares were designated as 5% Series B Cumulative Convertible Perpetual Preferred Stock (“Series B Preferred Stock”) in March 2005. Series B Preferred Stock As of April 30, 2023, the Company had 105,875 shares of Series B Preferred Stock, with a liquidation preference of $1,000.00 per share, authorized for issuance. As of April 30, 2023 and October 31, 2022, there were 64,020 shares of Series B Preferred Stock issued and outstanding, with a carrying value of $59.9 million. Dividends of $1.6 million were paid in cash during each of the six month periods ended April 30, 2023 and 2022.

Loss Per Share

Loss Per Share	6 Months Ended
	Apr. 30, 2023
Loss Per Share
Loss Per Share	Note 13. Loss Per Share The calculation of basic and diluted loss per share was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended April 30, Six Months Ended April 30, ​ ​ 2023 ​ 2022 2023 ​ 2022 ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to FuelCell Energy, Inc. $ (34,303) ​ $ (30,217) ​ $ (52,925) ​ $ (70,841) ​ ​ Series B preferred stock dividends ​ (800) ​ ​ (800) ​ ​ (1,600) ​ ​ (1,600) ​ ​ Net loss attributable to common stockholders $ (35,103) ​ $ (31,017) ​ $ (54,525) ​ $ (72,441) ​ ​ Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average common shares outstanding – basic ​ 406,316,070 ​ ​ 372,615,824 ​ ​ 406,055,027 ​ ​ 369,626,543 ​ ​ Effect of dilutive securities (1) ​ - ​ ​ - ​ ​ - ​ ​ - ​ ​ Weighted average common shares outstanding – diluted ​ 406,316,070 ​ ​ 372,615,824 ​ ​ 406,055,027 ​ ​ 369,626,543 ​ ​ Net loss to common stockholders per share – basic $ (0.09) ​ $ (0.08) ​ $ (0.13) ​ $ (0.20) ​ ​ Net loss to common stockholders per share – diluted (1) $ (0.09) ​ $ (0.08) ​ $ (0.13) ​ $ (0.20) ​ ​ (1) Due to the net loss to common stockholders in each of the periods presented above, diluted loss per share was computed without consideration to potentially dilutive instruments as their inclusion would have been anti-dilutive. As of April 30, 2023 and 2022, potentially dilutive securities excluded from the diluted loss per share calculation are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ April 30, ​ ​ 2023 2022 ​ May 2017 Offering – Series C Warrants ​ ​ - ​ ​ 950,102 ​ Outstanding options to purchase common stock ​ ​ 18,291 ​ ​ 20,231 ​ Unvested Restricted Stock Units ​ ​ 7,039,970 ​ ​ 3,315,557 ​ 5% Series B Cumulative Convertible Perpetual Preferred Stock ​ ​ 37,837 ​ ​ 37,837 ​ Total potentially dilutive securities ​ ​ 7,096,098 ​ ​ 4,323,727 ​ ​

Restricted Cash

Restricted Cash	6 Months Ended
	Apr. 30, 2023
Restricted Cash.
Restricted Cash	Note 14. Restricted Cash As of April 30, 2023 and October 31, 2022, there was $30.2 million and $23.0 million, respectively, of restricted cash and cash equivalents pledged as performance security, reserved for future debt service requirements, and reserved for letters of credit for certain banking requirements and contracts. The allocation of restricted cash is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Cash Restricted for Outstanding Letters of Credit (1) ​ $ 9,062 ​ $ 4,993 Cash Restricted for PNC Sale-Leaseback Transactions (2) ​ ​ 5,843 ​ ​ 5,010 Cash Restricted for Crestmark Sale-Leaseback Transactions (3) ​ ​ 2,897 ​ ​ 2,894 Bridgeport Fuel Cell Park Project Debt Service and Performance Reserves (4) ​ ​ 10,285 ​ ​ 8,746 Other ​ ​ 2,143 ​ ​ 1,346 Total Restricted Cash ​ ​ 30,230 ​ ​ 22,989 Restricted Cash and Cash Equivalents – Short-Term (5) ​ ​ (4,778) ​ ​ (4,423) Restricted Cash and Cash Equivalents – Long-Term ​ $ 25,452 ​ $ 18,566 (1) Letters of credit outstanding as of April 30, 2023 expire on various dates through December 2028. The increase from October 31, 2022 represents a letter of credit entered into for a project asset-specific gas contract. (2) Long and short-term reserve that was to be used primarily to fund future module exchanges for operating projects falling under PNC sale-leaseback transactions (which transactions were terminated following the end of the quarter). (3) Long and short-term reserve that is to be used primarily to fund future module exchanges and other performance obligations under Crestmark sale-leaseback transactions. (4) Long and short-term reserves for the Bridgeport Fuel Cell Park Project that were to be used to fund future module exchanges and other performance requirements (which reserves were released following the end of the quarter). (5) Short-term restricted cash and cash equivalents are amounts expected to be released and classified as unrestricted cash within twelve months of the balance sheet date.

Debt

Debt	6 Months Ended
	Apr. 30, 2023
Debt
Debt	Note 15. Debt Debt as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Connecticut Green Bank Loan ​ $ 4,800 ​ $ 4,800 Connecticut Green Bank Loan (Bridgeport Fuel Cell Project) ​ ​ 3,077 ​ ​ 3,507 Liberty Bank Term Loan Agreement (Bridgeport Fuel Cell Project) ​ ​ 4,340 ​ ​ 5,382 Fifth Third Bank Term Loan Agreement (Bridgeport Fuel Cell Project) ​ ​ 4,340 ​ ​ 5,382 Finance obligation for sale-leaseback transactions ​ ​ 56,961 ​ ​ 56,625 State of Connecticut Loan ​ ​ 7,342 ​ ​ 7,774 Finance lease obligations ​ ​ 35 ​ ​ 57 Deferred finance costs ​ ​ (977) ​ ​ (1,152) Total debt and finance obligations ​ ​ 79,918 ​ ​ 82,375 Current portion of long-term debt and finance obligations ​ ​ (13,289) ​ ​ (13,198) Long-term debt and finance obligations ​ $ 66,629 ​ $ 69,177 ​ ​ Subsequent to the end of the quarter, the Company entered into a project finance facility, the proceeds of which were used, in part, to pay off (i) approximately $1.8 million of the Company’s long-term indebtedness to Connecticut Green Bank (referred to in the table above as the “Connecticut Green Bank Loan”), and (ii) all of the outstanding senior and subordinated indebtedness of the Company and/or its subsidiaries to Liberty Bank, Fifth Third Bank and Connecticut Green Bank related to the Bridgeport Fuel Cell Project. See Note 18. “Subsequent Events” for additional information.

Benefit Plans

Benefit Plans	6 Months Ended
	Apr. 30, 2023
Benefit Plans
Benefit Plans	Note 16. Benefit Plans We have stockholder approved equity incentive plans, a stockholder approved Employee Stock Purchase Plan and an employee tax-deferred savings plan which are described in more detail below. 2018 Omnibus Incentive Plan The Company’s 2018 Omnibus Incentive Plan (as amended and restated from time to time, the “2018 Incentive Plan”) authorizes grants of stock options, stock appreciation rights (“SARs”), restricted stock awards (“RSAs”), restricted stock units (“RSUs”), performance shares, performance units and incentive awards to employees, directors, consultants and advisors. Stock options, RSAs, RSUs and SARs have restrictions as to transferability. Stock option exercise prices are fixed by the Company’s Board of Directors but shall not be less than the fair market value of our common stock on the date of the grant. SARs may be granted in conjunction with stock options. Of the 12,333,333 shares of the Company’s common stock authorized to be issued under the 2018 Incentive Plan as of April 30, 2023, 3,517,296 remained available for grant as of April 30, 2023. Of the shares remaining available for grant, the Company had reserved, for potential future grant, up to 2,036,257 performance stock units if maximum performance is achieved. See Note 18. “Subsequent Events” for information regarding the recent amendment to the 2018 Incentive Plan to increase the number of shares authorized to be issued under the 2018 Incentive Plan. Long-Term Incentive Plans The Company’s Board of Directors periodically approves Long Term Incentive Plans which include performance-based awards tied to the Company’s common stock price as well as time-vesting awards. None of the awards granted as part of Long-Term Incentive Plans include any dividend equivalent or other stockholder rights. To the extent the awards are earned, they may be settled in shares or cash of an equivalent value at the Company’s option. Fiscal Year 2023 Long Term Incentive Plan: On December 5, 2022, the Company’s Board of Directors approved a Long-Term Incentive Plan for fiscal year 2023 (the “FY 2023 LTI Plan”) as a sub-plan consisting of awards made under the 2018 Incentive Plan. The participants in the FY 2023 LTI Plan are members of senior management. The FY 2023 LTI Plan consists of two award components: 1) Relative Total Shareholder Return (“TSR”) Performance Share Units (“PSU”). The PSUs granted during the six months ended April 30, 2023 will be earned over the performance period ending on October 31, 2025, but will remain subject to a continued service-based vesting requirement until the third anniversary of the date of grant. The performance measure for the relative TSR PSUs is the TSR of the Company relative to the TSR of the Russell 2000 from November 1, 2022 through October 31, 2025. The Compensation Committee established the performance assessment criteria for the relative TSR PSUs as the TSR of the Company relative to the TSR of the Russell 2000, with the award calibration being 100% plus or minus 0.5 x the difference between the Company’s TSR and the Russell 2000 Index composite TSR. The award is capped at 200% of the target number of PSUs, and the award is further capped at 100% of the target number of PSUs if the Company’s absolute TSR over the performance period is negative. The Company’s TSR is calculated by subtracting the Company’s beginning stock price (defined as the average closing price of the Company’s common stock over the 60 consecutive trading days ending on October 31, 2022) from the ending stock price (defined as the average closing price of the Company’s common stock over the 60 consecutive trading days ending on October 31, 2025), adding any dividends during the period, and then dividing the result by the Company’s beginning stock price. Given that the performance period is still open, the Company has reserved shares equal to 200% of the target number of PSUs, subject to performance during the remaining performance period as well as vesting based on continued service until December 5, 2025 (the third anniversary of the grant date). 2) Time-vesting RSUs. The time-vesting RSUs granted during the six months ended April 30, 2023 will vest at a rate of one -third of the total number of RSUs on each of the first three anniversaries of the date of grant. Other Equity Incentive Plans The Company’s 2006 and 2010 Equity Incentive Plans remain in effect only to the extent of awards outstanding under the plans as of April 30, 2023. Share-Based Compensation Share-based compensation was reflected in the Consolidated Statements of Operations and Comprehensive Loss as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended April 30, ​ Six Months Ended April 30, ​ 2023 2022 ​ 2023 2022 Cost of revenues ​ $ 413 ​ $ 185 ​ $ 747 ​ $ 338 Administrative and selling expense ​ ​ 2,320 ​ ​ 1,350 ​ ​ 4,262 ​ ​ 2,528 Research and development expense ​ ​ 363 ​ ​ 106 ​ ​ 659 ​ ​ 184 ​ ​ $ 3,096 ​ $ 1,641 ​ $ 5,668 ​ $ 3,050 ​ Restricted Stock Units Including Performance Share Units The following table summarizes our RSU activity for the six months ended April 30, 2023: ​ ​ ​ ​ ​ ​ ​ Restricted Stock Units ​ Shares Weighted-Average Fair Value Outstanding as of October 31, 2022 ​ ​ 2,520,881 ​ $ 7.93 Granted - PSUs ​ ​ 1,124,953 ​ ​ 5.50 Granted - time-vesting RSUs ​ ​ 3,781,370 ​ ​ 3.41 Vested ​ ​ (261,059) ​ ​ 7.03 Forfeited ​ ​ (64,056) ​ ​ 7.55 Outstanding as of January 31, 2023 ​ ​ 7,102,089 ​ $ 5.18 Granted - time-vesting RSUs ​ ​ 64,550 ​ ​ 3.29 Vested ​ ​ (84,669) ​ ​ 5.96 Forfeited ​ ​ (42,000) ​ ​ 3.65 Outstanding as of April 30, 2023 ​ ​ 7,039,970 ​ $ 5.16 ​ On December 5, 2022, 2,249,890 RSUs were awarded to senior management under the FY 2023 LTI Plan, which included 1,124,953 PSUs and 1,124,937 time-based vesting RSUs. The PSUs were valued based on a Monte-Carlo Simulation, and the estimated fair value of the relative TSR PSUs was $5.50 per share. The PSUs and time-based vesting RSUs are expensed over the three-year service period. In addition to the awards granted to senior management, during the six months ended April 30, 2023, the Board of Directors also granted a total of 2,720,983 time-based vesting RSUs to certain salaried employees to promote ownership of the Company’s equity and retention. The time-based vesting RSUs granted during the six months ended April 30, 2023 vest at a rate of one PSUs are issued assuming participants achieve 100% target performance. The Company also reserves additional shares assuming the maximum performance targets are met.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Apr. 30, 2023
Commitments and Contingencies
Commitments and Contingencies	Note 17. Commitments and Contingencies Service Agreements Under the provisions of its service agreements, the Company provides services to maintain, monitor, and repair customer power plants to meet minimum operating levels. Under the terms of such service agreements, the particular power plant must meet a minimum operating output during defined periods of the term. If minimum output falls below the contract requirement, the Company may be subject to performance penalties and/or may be required to repair or replace the customer’s fuel cell module(s). Power Purchase Agreements Under the terms of the Company’s PPAs, customers agree to purchase power or other values streams delivered such as hydrogen, steam, water, and/or carbon from the Company’s fuel cell power platforms at negotiated rates. Electricity rates are generally a function of the customers’ current and estimated future electricity pricing available from the grid. As owner or lessee of the power platforms, the Company is responsible for all operating costs necessary to maintain, monitor and repair the power platforms. Under certain agreements, the Company is also responsible for procuring fuel, generally natural gas or biogas, to run the power platforms. In addition, under the terms of some of the PPAs, the Company may be subject to a performance penalty if the Company does not meet certain performance requirements. Project Fuel Exposure ​ Certain of our PPAs for project assets in our generation operating portfolio and project assets under construction expose us to fluctuating fuel price risks as well as the risk of being unable to procure the required amounts of fuel and the lack of alternative available fuel sources. We seek to mitigate our fuel risk using strategies including: (i) fuel cost reimbursement mechanisms in our PPAs to allow for pass through of fuel costs (full or partial) where possible, which we have done with our 14.9 MW operating project in Bridgeport, CT; (ii) procuring fuel under fixed price physical supply contracts with investment grade counterparties, which we have done for twenty years for our Tulare BioMAT project, the initial seven years of the eighteen year PPA for our LIPA Yaphank Project, the initial two years of the twenty year PPA for our 14.0 MW Derby project and the initial two years of the twenty year hydrogen power purchase agreement for our Toyota project; and (iii) potentially entering into future financial hedges with investment grade counterparties to offset potential negative market fluctuations. The Company does not take a fundamental view on natural gas or other commodity pricing and seeks commercially available means to reduce commodity exposure. ​ There are currently three projects in development with fuel sourcing risk, which are the Toyota project, which requires procurement of RNG, and our Derby, CT 14.0 MW and 2.8 MW projects, both of which require natural gas for which there is no pass-through mechanism. Two-year fuel supply contracts have been executed for the Toyota project and the 14.0 MW project in Derby, CT. The Company will look to extend the duration of these contracts should market and credit conditions allow. Fuel sourcing and risk mitigation strategies for the 2.8 MW project in Derby, CT are being assessed and will be implemented as project operational dates become firm. Such strategies may require cash collateral or reserves to secure fuel or related contracts. If the Company is unable to secure fuel on favorable economic terms, it may result in impairment charges to the Derby project assets and further charges for the Toyota project asset. ​ While the Company is pursuing alternative sources of RNG for the Toyota project, charges are being recorded to cost of generation revenues for any project expenditures currently expected to be unrecoverable. To date, $36.4 million in charges have been recorded, which includes $4.5 million and $4.4 million in charges for the three months ended April 30, 2023 and 2022, respectively, and $11.6 million and $7.2 million in charges for the six months ended April 30, 2023 and 2022, respectively. As of April 30, 2023, the carrying value of the Toyota project on the Consolidated Balance Sheet totaled $22.1 million which represents the carrying value of inventory components that could be redeployed for alternative use. ​ Since the war in Ukraine began in February of 2022, there has been significant volatility in the global natural gas markets. As a result, in fiscal year 2022, the Company performed a recoverability analysis with respect to the Derby 14.0 MW and 2.8 MW projects and concluded that the assets are recoverable and therefore an impairment had not occurred. Should natural gas prices continue to rise, there could be an impairment in future periods. No triggering events occurred during the first six months of fiscal year 2023. The Company has risk mitigation strategies that it may implement in an effort to mitigate potential impacts including the ability to extend commercial operations dates. As of April 30, 2023, the carrying value of the 14.0 MW project in Derby, CT totaled $39.9 million and the carrying value of the 2.8 MW project in Derby, CT totaled $0.6 million. ​ Other As of April 30, 2023, the Company had unconditional purchase commitments aggregating $100.8 million for materials, supplies and services in the normal course of business. Legal Proceedings From time to time, the Company is involved in legal proceedings, including, but not limited to, regulatory proceedings, claims, mediations, arbitrations and litigation, arising out of the ordinary course of its business (“Legal Proceedings”). Although the Company cannot assure the outcome of such Legal Proceedings, management presently believes that the result of such Legal Proceedings, either individually, or in the aggregate, will not have a material adverse effect on the Company’s consolidated financial statements, and no material amounts have been accrued in the Company’s consolidated financial statements with respect to these matters.

Subsequent Events

Subsequent Events	6 Months Ended
	Apr. 30, 2023
Subsequent Events
Subsequent Events	Note 18. Subsequent Events Project Financing Facility ​ On May 19, 2023, FuelCell Energy Opco Finance 1, LLC (“Borrower”), a wholly owned subsidiary of FuelCell Energy Finance, LLC (“FCEF”), which, in turn, is a wholly owned subsidiary of FuelCell Energy, Inc. (“Parent”), entered into a Financing Agreement (the “Financing Agreement”) with, by and among Investec Bank plc in its capacities as a lender (“Investec Lender”), administrative agent (“Administrative Agent”), and collateral agent (“Collateral Agent”); Investec, Inc. as coordinating lead arranger and sole bookrunner; Bank of Montreal (Chicago Branch) in its capacity as a lender (“BMO Lender”) and as mandated lead arranger; and each of Liberty Bank, Amalgamated Bank and Connecticut Green Bank as lenders (collectively with Investec Lender and BMO Lender, the “Lenders”) for a term loan facility in an amount not to exceed $80.5 million (the “Term Loan Facility” and such term loan, the “Term Loan”) and a letter of credit facility in an amount not to exceed $6.5 million (the “LC Facility” and together with the Term Loan Facility, the “Financing Facility”). Borrower’s obligations under the Financing Agreement are secured by Parent’s interest in six operating fuel cell generation projects: (i) the Bridgeport Fuel Cell Project, located in Bridgeport, Connecticut; (ii) the Central CT State University Project, located in New Britain, Connecticut; (iii) the Pfizer Project, located in Groton, Connecticut; (iv) the LIPA Yaphank Project, located in Long Island, New York; (v) the Riverside Regional Water Quality Control Plant Project, located in Riverside, California; and (vi) the Santa Rita Jail Project, located in Alameda County, California (each, a “Project” and collectively, the “Projects”). Immediately prior to the closing on the Financing Facility, which closing occurred on May 19, 2023, Parent caused to be transferred to Borrower all of the outstanding equity interests in: (i) Bridgeport Fuel Cell, LLC (the “Bridgeport Project Company”), the entity that owns the Bridgeport Fuel Cell Project; (ii) New Britain Renewable Energy, LLC (the “CCSU Project Company”), the entity that owns the Central CT State University Project; (iii) Groton Fuel Cell 1, LLC (the “Pfizer Project Company”), the entity that owns the Pfizer Project; (iv) Riverside Fuel Cell, LLC (the “Riverside Project Company”), the entity that owns the Riverside Regional Water Quality Control Plant Project; (v) SRJFC, LLC (the “Santa Rita Project Company”), the entity that owns the Santa Rita Jail Project; and (vi) Fuel Cell YT Holdco, LLC (the “Class B Member”), the entity that owns Parent’s Class B membership interest in YTBFC Holdco, LLC (the “Yaphank Tax Equity Partnership”), the tax equity partnership with Renewable Energy Investors, LLC (the “Class A Member”), as tax equity investor, which Yaphank Tax Equity Partnership, in turn, owns Yaphank Fuel Cell Park, LLC (the “Yaphank Project Company”), the entity that owns the LIPA Yaphank Project. At the time of closing on the Financing Facility: (i) the Bridgeport Fuel Cell Project was encumbered by senior and subordinated indebtedness to Liberty Bank, Fifth Third Bank and Connecticut Green Bank in the aggregate amount of approximately $11.4 million; and (ii) the Pfizer Project, the Riverside Regional Water Quality Control Plant Project and the Santa Rita Jail Project were subject to sale and leaseback transactions and agreements with PNC Energy Capital, LLC (“PNC”) in which the lease buyout amounts, including sales taxes, were approximately $15.7 million, $3.7 million and $2.8 million, respectively. In connection with closing on the Financing Facility, all of the foregoing indebtedness and lease buyout amounts were repaid and extinguished with proceeds of the Term Loan and funds of approximately $7.3 million that were released from restricted and unrestricted reserve accounts held at PNC at the time of closing, resulting in the applicable project company’s re-acquiring ownership of the three leased projects from PNC, the termination of the agreements with PNC related to the sale-leaseback transactions, and the termination of the senior and subordinated credit agreements with, the related promissory notes issued to, and the related pledge and security agreements with, Liberty Bank, Fifth Third Bank and Connecticut Green Bank related to the Bridgeport Fuel Cell Project. Further, in connection with the closing on the Financing Facility and the termination of the senior and subordinated credit agreements with Liberty Bank, Fifth Third Bank and Connecticut Green Bank related to the Bridgeport Fuel Cell Project, Fifth Third Bank and the Bridgeport Project Company agreed that the obligations arising out of the swap transactions contemplated by their related interest rate swap agreement were terminated and waived and the swap agreement was effectively terminated. In addition, in connection with closing on the Financing Facility, proceeds of the Term Loan were used to repay a portion of Parent’s long-term indebtedness to Connecticut Green Bank in the amount of approximately $1.8 million. At the closing, the entire amount of the Term Loan portion of the Financing Facility, $80.5 million, was drawn down. After payment of fees and transaction costs (including fees to the Lenders and legal costs) of approximately $2.9 million in the aggregate, the remaining proceeds of approximately $77.6 million were used as follows: (i) approximately $15.0 million was used (in addition to the approximately $7.3 million released from restricted and unrestricted reserve accounts held at PNC) to pay the lease buyout amounts and sales taxes referred to above and to re-acquire the three projects owned by PNC as referred to above; (ii) approximately $11.4 million was used to extinguish the indebtedness to Liberty Bank, Fifth Third Bank, and Connecticut Green Bank relating to the Bridgeport Fuel Cell Project; (iii) approximately $1.8 million was used to repay a portion of Parent’s long-term indebtedness to Connecticut Green Bank; (iv) $14.5 million was used to fund a capital expenditure reserve account required to be maintained pursuant to the terms and conditions of the Financing Agreement (which will be classified as restricted cash on the Company’s Consolidated Balance Sheet); and (v) approximately $34.9 million was distributed to Parent for use as Parent determines in its sole discretion. In addition, in connection with the extinguishment of the Company’s indebtedness to Liberty Bank and Fifth Third Bank referred to above, approximately $11.2 million of restricted cash was released to the Company from Liberty Bank and Fifth Third Bank. Taking into consideration the release of such funds, the total net proceeds to the Company from these transactions were approximately $46.1 million (which will be classified as unrestricted cash on the Company’s Consolidated Balance Sheet). The Term Loan portion of the Financing Facility will accrue interest on the unpaid principal amount calculated from the date of such Term Loan until the maturity date thereof at a rate per annum during each Interest Period (as defined in the Financing Agreement) for such Term Loan equal to (A) with respect to SOFR Rate Loans, (i) the Adjusted Daily Compounded SOFR for such Interest Period with respect to SOFR Rate Loans plus plus Quarterly principal amortization obligations are also required to be made (based on 17-year ​ Pursuant to the terms and conditions of the Financing Agreement, Borrower is required to maintain a capital expenditures reserve to pay for expected module replacements. The total reserve balance is required to reach $29.0 million, $14.5 million of which was funded out of the closing advance of the Term Loan and the remainder of which is to be funded pursuant to an agreed upon funding schedule through cash flows generated by the Projects set forth in the Financing Agreement. Pursuant to the terms and conditions of the Financing Agreement, Borrower is required to maintain a debt service reserve of not less than six months of the scheduled principal and interest payments. The letter of credit component of the Financing Facility is for the purpose of obtaining letters of credit to satisfy such obligation; at the closing, an Irrevocable Letter of Credit was issued by Investec Bank plc as the issuing bank in favor of the Collateral Agent for the benefit of the Lenders in the amount of $6.5 million to satisfy the debt service reserve funding obligation. ​ Pursuant to the Financing Agreement, within 30 days of the financial close of the Financing Agreement, Borrower is required to enter into one or more hedge transactions, with a Lender or an affiliate thereof pursuant to one or more interest rate agreements, to hedge Borrower’s interest rate exposure relating to the Term Loan from floating to fixed. Such hedge transactions are required to be in effect at all times during the entire amortization period and have an aggregate notional amount subject to the hedge transactions at any time equal to at least 75% and no more than 105% of the aggregate principal balance of the Term Loan outstanding (taking into account scheduled amortization of the Term Loan). Upon closing, on May 19, 2023, Borrower entered into an ISDA 2002 Master Agreement (the “Investec Master Agreement”) and an ISDA Schedule to the 2002 Master Agreement (the “Investec Schedule”) with Investec Bank plc as a hedge provider, and an ISDA 2002 Master Agreement (the “BMO Master Agreement”) and an ISDA Schedule to the 2002 Master Agreement (the “BMO Schedule”) with Bank of Montreal (Chicago Branch) as a hedge provider. On May 22, 2023, Borrower executed the related trade confirmations for these interest rate swap agreements with these hedge providers to protect against adverse price movements in the floating SOFR rate associated with 100% of the aggregate principal balance of the Term Loan outstanding. Pursuant to the terms of such agreements, Borrower will pay a fixed rate of interest of 3.716%. The net interest rate across the Financing Agreement and the swap transaction is 6.366% in the first four years and 6.866% thereafter. The obligations of Borrower to the hedge providers under the interest rate swap agreements are treated as obligations under the Financing Agreement and, accordingly, are secured, on a pari passu basis, by the same collateral securing the obligations of Borrower under the Financing Agreement, which collateral is described below. ​ The Financing Agreement contains certain reporting requirements and other affirmative and negative covenants which are customary for transactions of this type. Included in the covenants are covenants that: (i) the Yaphank Project Company obtain ongoing three year extensions of its current gas agreement; (ii) any annual operating expense budget that exceeds 115% of the Base Case Model (as defined in the Financing Agreement) for that year be approved by the Required Lenders (i.e., Lenders constituting more than 50% of the amounts loaned); (iii) Borrower maintain a debt service coverage ratio of not less than 1.20:1.00 (based on the trailing 12 months and tested every six months); and (iv) the Class B Member is required to exercise its option to purchase the Class A Member’s interest in the Yaphank Tax Equity Partnership during the six month period following the “flip Point” as set forth in the limited liability company agreement for the Yaphank Tax Equity Partnership. The Financing Agreement also contains customary representations and warranties and customary events of default that cause, or entitle the Lenders to cause, the outstanding loans under the Financing Agreement to become immediately due and payable. The Term Loan may be prepaid at any time at the option of Borrower without premium or penalty other than any “liquidation costs” if such prepayment occurs other than at the end of an Interest Period. In addition, there are certain mandatory repayments required under the Financing Agreement, including in connection with any sale or disposition of all of the Projects or of any of the LIPA Yaphank Project, the Bridgeport Fuel Cell Project or the Pfizer Project. If the Company disposes of any of the Riverside Regional Water Quality Control Plant Project, the Santa Rita Jail Project or the Central CT State University Project, Borrower is required to prepay an amount of the Term Loan based on the then stipulated value of the disposed Project. ​ Simultaneously with Borrower entering into the Financing Agreement, FCEF (as pledgor), Borrower and each of the Bridgeport Project Company, the Pfizer Project Company, the Riverside Project Company, the Santa Rita Project Company, the CCSU Project Company and the Class B Member, each as a subsidiary grantor party and guarantor, entered into an Omnibus Guarantee, Pledge and Security Agreement (the “Security Agreement”) with Investec Bank plc as Collateral Agent, pursuant to which, as collateral for the Term Loan Facility, the LC Facility and the hedge agreements (i) FCEF granted to Collateral Agent a security interest in all of FCEF’s equity interest in Borrower; (ii) Borrower granted to Collateral Agent a security interest in all of Borrower’s assets consisting of its equity interests in the Bridgeport Project Company, the Pfizer Project Company, the Riverside Project Company, the Santa Rita Project Company, the CCSU Project Company and the Class B Member; (iii) each of the Bridgeport Project Company, the Pfizer Project Company, the Riverside Project Company, the Santa Rita Project Company and the CCSU Project Company granted to Collateral Agent a security interest in all of each such entity’s assets consisting principally of the respective generation facilities and project agreements; and (iv) the Class B Member granted to Collateral Agent a security interest in all of such Class B Member’s assets, consisting principally of its equity interest in the Yaphank Tax Equity Partnership. Pursuant to the Security Agreement, each of the subsidiary grantor parties jointly and severally guaranteed payment of all of the obligations secured by the Security Agreement. Simultaneously with the execution of the Financing Agreement, Borrower, Investec Bank plc as Collateral Agent and Administrative Agent and Liberty Bank as Depositary Agent entered into a Depositary Agreement (the “Depositary Agreement”) pursuant to which Borrower established certain accounts at Liberty Bank, all of which were pledged to Collateral Agent as security for the Term Loan Facility, the LC Facility and the hedge agreements, including a Revenue Account; a Debt Service Reserve Account; a Redemption Account (for prepayments); a Capital Expenditure Reserve Account; and a Distribution Reserve Account (in each case as defined in the Depositary Agreement). Pursuant to the terms of the Financing Agreement and the Depositary Agreement, Borrower may make quarterly distributions to FCEF and Parent provided that: (i) no Event of Default or Default (in each case as defined in the Financing Agreement) exists under the Financing Facility; (ii) all reserve accounts have been funded; (iii) no letter of credit loans or unpaid drawings are outstanding with regard to any drawn down letter of credit under the LC Facility; (iv) Borrower has maintained a greater than 1.20:1.00 debt service coverage ratio for the immediate 12 month period; and (v) no Cash Diversion Event (i.e., certain events that would adversely impact distributions to the Class B Member in connection with the LIPA Yaphank Project, as further defined in the Financing Agreement) has occurred. Beginning with the quarter ending June 2025 and continuing until the quarter ending March 2026, prior to making contributions to the Debt Service Reserve Account or the Capital Expenditure Reserve Account or having funds available for distribution, out of operating cash flow, Borrower is required to make a quarterly payment to the Administrative Agent (on behalf of the Lenders) in the amount of $675,000 per quarter to be applied to outstanding principal. ​ Third Amendment to Assistance Agreement with the State of Connecticut ​ In April 2023, the Company signed a Third Amendment (the “Third Amendment”) to the Assistance Agreement with the State of Connecticut (which Assistance Agreement was originally entered into in November 2015 and previously amended in April 2017 and January 2019). The Third Amendment was approved by the State of Connecticut Office of Attorney General on May 18, 2023, and the State of Connecticut Office of Attorney General released, and the Company received, the countersigned Third Amendment on May 24, 2023, at which time the Third Amendment became effective. The Third Amendment further extends the Target Date (as defined elsewhere herein) to October 31, 2024 and updates the Employment Obligation (as defined elsewhere herein) to require the Company to retain 538 full-time positions in Connecticut on or before October 31, 2024 and to maintain such positions for 24 24 24 ​ If, as a result of the Job Audit, the Commissioner determines that the Company has failed to meet the updated Employment Obligation, the Company will be required to immediately repay a penalty of $14,225.00 per each full-time employment position below the updated Employment Obligation. The amount repaid will be applied first to any outstanding fees, penalties or interest due, and then against the outstanding balance of the loan. ​ If, as a result of the Job Audit, the Commissioner determines that the Company has met the updated Employment Obligation and has created an additional 91 full-time employment positions, for a total of 629 full-time employees, the Company may receive a credit in the amount of $2.0 million, which will be applied against the then-outstanding principal balance of the loan. Upon application of such credit, the Commissioner will recalculate the monthly payments of principal and interest such that such monthly payments shall amortize the then remaining principal balance over the remaining term of loan. ​ Amendment and Restatement of the FuelCell Energy, Inc. 2018 Employee Stock Purchase Plan At the Company’s 2023 Annual Meeting of Stockholders, which was called to order and adjourned on April 6, 2023 and April 27, 2023 and was reconvened and concluded on May 22, 2023 (the “Annual Meeting”), the Company’s stockholders approved the amendment and restatement of the FuelCell Energy, Inc. 2018 Employee Stock Purchase Plan (as so amended and restated, the “Amended and Restated ESPP”), which had previously been approved by the Company’s Board of Directors (the “Board”), subject to stockholder approval. The purpose of the amendment and restatement of the 2018 Employee Stock Purchase Plan was to authorize the Company to issue up to 500,000 additional shares of the Company’s common stock under the Amended and Restated ESPP. Following the approval of the amendment and restatement (and therefore the Amended and Restated ESPP) by the Company’s stockholders at the Annual Meeting, the Amended and Restated ESPP provides the Company with the authority to issue a total of 541,667 shares of the Company’s common stock. The Amended and Restated ESPP also increases the limit on the number of shares of the Company’s common stock that any individual participant may purchase during an offering period to 1,000 shares. The Amended and Restated ESPP, which is intended to satisfy the requirements of Section 423 of the Internal Revenue Code of 1986, as amended, allows the Company to provide eligible employees of the Company and of certain designated subsidiaries with the opportunity to voluntarily participate in the Amended and Restated ESPP, enabling such participants to purchase shares of the Company’s common stock at a discount to market price at the time of such purchase. The Board may, in its sole discretion, terminate the Amended and Restated ESPP at any time. If the Board does not earlier terminate the Amended and Restated ESPP, the Amended and Restated ESPP will terminate on the date on which all shares of common stock available for issuance have been sold pursuant to purchase rights exercised under the Amended and Restated ESPP. Amendment and Restatement of the FuelCell Energy, Inc. Second Amended and Restated 2018 Omnibus Incentive Plan At the Annual Meeting, the Company’s stockholders approved the amendment and restatement of the FuelCell Energy, Inc. Second Amended and Restated 2018 Omnibus Incentive Plan (as so amended and restated, the “Third Amended and Restated Incentive Plan”), which had previously been approved by the Board, subject to stockholder approval. The purpose of the amendment and restatement of the Second Amended and Restated 2018 Omnibus Incentive Plan was to authorize the Company to issue up to 6,000,000 additional shares of the Company’s common stock pursuant to awards under the Third Amended and Restated Incentive Plan. Following the approval of the amendment and restatement (and therefore the Third Amended and Restated Incentive Plan) by the Company’s stockholders at the Annual Meeting, the Third Amended and Restated Incentive Plan provides the Company with the authority to issue a total of 18,333,333 shares of the Company’s common stock. The Third Amended and Restated Incentive Plan authorizes grants of stock options, stock appreciation rights, restricted stock, restricted stock units, shares, performance shares, performance units, incentive awards and dividend equivalent units to officers, other employees, directors, consultants and advisors. Up to 1,833,333 shares of the Company’s common stock may be issued pursuant to the exercise of incentive stock options. The Board or the administrator of the Third Amended and Restated Incentive Plan may terminate the Third Amended and Restated Incentive Plan at any time. No award may be granted under the Third Amended and Restated Plan after the tenth anniversary of the approval of the Third Amended and Restated Plan by stockholders at the Annual Meeting.

Nature of Business and Basis _2

Nature of Business and Basis of Presentation (Policies)	6 Months Ended
	Apr. 30, 2023
Nature of Business and Basis of Presentation
Basis of Presentation	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, 2023 and 2022 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, 2022 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, 2022, 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. ​ Certain reclassifications have been made to the prior year amounts to conform to the presentation for the three and six months ended April 30, 2023. Interest income for the three and six months ended April 30, 2022, which was previously included within Other expense, net has been reclassified to Interest income in the Consolidated Statement of Operations and Comprehensive Loss.
Principles of Consolidation	Principles of Consolidation ​ The unaudited consolidated financial statements reflect our accounts and operations and those of our subsidiaries in which we have a controlling financial interest. We use a qualitative approach in assessing the consolidation requirement for each of our variable interest entities ("VIEs"), which are tax equity partnerships further described in Note 3. “Tax Equity Financings.” This approach focuses on determining whether we have the power to direct those activities of the tax equity partnerships that most significantly affect their economic performance and whether we have the obligation to absorb losses, or the right to receive benefits, that could potentially be significant to the tax equity partnerships. For all periods presented, we have determined that we are the primary beneficiary in all of our tax equity partnerships. We evaluate our tax equity partnerships on an ongoing basis to ensure that we continue to be the primary beneficiary.
Use of Estimates	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 assets and liabilities. Estimates are used in accounting for, among other things, revenue recognition, lease right-of-use assets and liabilities, 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), 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.
Liquidity	Liquidity Our principal sources of cash have been proceeds from the sale of our products and projects, electricity generation revenues, research and development and service agreements with third parties, sales of our common stock through public equity offerings, and proceeds from debt, project financing and tax monetization transactions. We have utilized this cash to accelerate the commercialization of our solid oxide platforms, develop new capabilities to separate and capture carbon, develop and construct project assets, invest in capital improvements and expansion of our operations, perform research and development on Advanced Technologies, pay down existing outstanding indebtedness, and meet our other cash and liquidity needs. As of April 30, 2023, unrestricted cash and cash equivalents totaled $246.8 million compared to $458.1 million as of October 31, 2022. During the six months ended April 30, 2023, the Company invested $138.2 million in United States (U.S.) Treasury Securities and $63.3 million of the U.S. Treasury Securities matured. The amortized cost of the U.S. Treasury Securities outstanding as of April 30, 2023 totaled $76.4 million as of April 30, 2023 compared to $0 as of October 31, 2022 and is classified as Investments - short-term on the Consolidated Balance Sheets. The maturity dates for the outstanding U.S. Treasury Securities range from May 4, 2023 to October 5, 2023. On July 12, 2022, the Company entered into an Open Market Sale Agreement with Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canaccord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC (the “Open Market Sale Agreement”) with respect to an at the market offering program under which the Company may, from time to time, offer and sell up to 95.0 million shares of the Company’s common stock. From the date of the Open Market Sale Agreement through April 30, 2023, the Company sold approximately 19.4 million shares under the Open Market Sale Agreement at an average sale price of $3.60 per share, resulting in gross proceeds of approximately $70.0 million before deducting sales commissions and fees. During the three and six months ended April 30, 2023, approximately 0.9 million shares were sold under the Open Market Sale Agreement at an average sale price of $3.02 per share, resulting in gross proceeds of approximately $2.9 million. As of April 30, 2023, approximately 75.6 million shares were available for issuance under the Open Market Sale Agreement. The Company currently intends to use the net proceeds from this offering to accelerate the development and commercialization of its product platforms (including, but not limited to, its solid oxide and carbon capture platforms), for project development, market development, and internal research and development, to invest in capacity expansion for solid oxide and carbonate fuel cell manufacturing, and for project financing, working capital support, and general corporate purposes. The Company may also use the net proceeds from this offering to invest in joint ventures, acquisitions, and strategic growth investments and to acquire, license or invest in products, technologies or businesses that complement its business. See Note 11. “Stockholders’ Equity” for additional information regarding the Open Market Sale Agreement. ​ We believe that our unrestricted cash and cash equivalents, expected receipts from our contracted backlog, funds received upon the maturity of U.S. Treasury Securities, and release of short-term restricted cash less expected disbursements over the next twelve months will be sufficient to allow the Company to meet its obligations for at least one year from the date of issuance of these financial statements. ​ To date, we have not achieved profitable operations or sustained positive cash flow from operations. The Company’s future liquidity, for fiscal year 2023 and in the long-term, will depend on its ability to (i) timely complete current projects in process within budget, (ii) increase cash flows from its generation operating portfolio, including by meeting conditions required to timely commence operation of new projects, operating its generation operating portfolio in compliance with minimum performance guarantees and operating its generation operating portfolio in accordance with revenue expectations, (iii) obtain financing for project construction and manufacturing expansion, (iv) obtain permanent financing for its projects once constructed, (v) increase order and contract volumes, which would lead to additional product sales, service agreements and generation revenues, (vi) obtain funding for and receive payment for research and development under current and future Advanced Technologies contracts, (vii) successfully commercialize its Advanced Technologies platforms, including its solid oxide, hydrogen and carbon capture platforms, (viii) implement capacity expansion for solid oxide product manufacturing, (ix) implement the product cost reductions necessary to achieve profitable operations, (x) manage working capital and the Company’s unrestricted cash balance and (xi) access the capital markets to raise funds through the sale of debt and equity securities, convertible notes, and other equity-linked instruments. We are continually assessing different means by which to accelerate the Company’s growth, enter new markets, commercialize new products, and enable capacity expansion. Therefore, from time to time, the Company may consider and enter into agreements for one or more of the following: negotiated financial transactions, minority investments, collaborative ventures, technology sharing, transfer or other technology license arrangements, joint ventures, partnerships, acquisitions or other business transactions for the purpose(s) of geographic or manufacturing expansion and/or new product or technology development and commercialization, including hydrogen production through our carbonate and solid oxide platforms and storage and carbon capture, sequestration and utilization technologies. Our business model requires substantial outside financing arrangements and satisfaction of the conditions of such arrangements to construct and deploy our projects to facilitate the growth of our business. The Company has invested capital raised from sales of its common stock to build out its project portfolio. The Company has also utilized and expects to continue to utilize a combination of long-term debt and tax equity financing (e.g., sale-leaseback transactions, partnership flip transactions and the monetization and/or transfer of eligible investment and production tax credits) to finance its project asset portfolio as these projects commence commercial operations, particularly in light of the passage of the Inflation Reduction Act in August 2022. The Company may also seek to undertake private placements of debt securities of a portfolio of assets to finance its project asset portfolio. The proceeds of any such financing, if obtained, may allow the Company to reinvest capital back into the business and to fund other projects. We may also seek to obtain additional financing in both the debt and equity markets in the future. If financing is not available to us on acceptable terms if and when needed, or on terms acceptable to us or our lenders, if we do not satisfy the conditions of our financing arrangements, if we spend more than the financing approved for projects, if project costs exceed an amount that the Company can finance, or if we do not generate sufficient revenues or obtain capital sufficient for our corporate needs, we may be required to reduce or slow planned spending, reduce staffing, sell assets, seek alternative financing and take other measures, any of which could have a material adverse effect on our financial condition and operations.
Recently Adopted Accounting Guidance and Recent Accounting Guidance Not Yet Effective	Recently Adopted Accounting Guidance There is no recently adopted accounting guidance. Recent Accounting Guidance Not Yet Effective There is no recent accounting guidance that is not yet effective.

Investments - Short-Term (Table

Investments - Short-Term (Tables)	6 Months Ended
	Apr. 30, 2023
Investments - Short-Term
Schedule of investments in held-to-maturity securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized ​ Gross unrealized ​ Gross unrealized ​ ​ cost gains ​ losses Fair value U.S. Treasury Securities ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 30, 2023 ​ $ 76,400 $ - $ (17) $ 76,383

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Apr. 30, 2023
Inventories
Components of Inventories	Inventories (current and long-term) as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Raw materials ​ $ 39,261 ​ $ 30,624 Work-in-process (1) ​ ​ 55,582 ​ ​ 67,834 Inventories ​ ​ 94,843 ​ ​ 98,458 Inventories – current ​ ​ (87,294) ​ ​ (90,909) Inventories – long-term (2) ​ $ 7,549 ​ $ 7,549 (1) Work-in-process includes the standard components of inventory used to build the typical modules or module components that are intended to be used in future project asset construction or power plant orders or for use under the Company’s service agreements. Included in work-in-process as of April 30, 2023 and October 31, 2022 was $35.2 million and $54.0 million, respectively, of completed standard components and modules. (2) Long-term inventory includes modules that are contractually required to be segregated for use as exchange modules for specific project assets.

Project Assets (Tables)

Project Assets (Tables)	6 Months Ended
	Apr. 30, 2023
Project Assets
Summary of Project Assets	Project assets as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ Estimated ​ 2023 2022 Useful Life Project Assets – Operating ​ $ 210,211 ​ $ 154,736 ​ 4-20 years Accumulated depreciation ​ ​ (36,081) ​ ​ (29,546) ​ ​ Project Assets – Operating, net ​ ​ 174,130 ​ ​ 125,190 ​ ​ Project Assets – Construction in progress ​ ​ 63,021 ​ ​ 107,696 ​ ​ Project Assets, net ​ $ 237,151 ​ $ 232,886 ​ ​

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Apr. 30, 2023
Goodwill and Intangible Assets
Summary of Intangible Assets	The following tables summarize the carrying value of the Company’s intangible assets as of April 30, 2023 and October 31, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of April 30, 2023 Gross Amount Accumulated Amortization Net Amount In-Process Research and Development ​ $ 9,592 ​ $ - ​ $ 9,592 Bridgeport PPA ​ ​ 12,320 ​ ​ (5,187) ​ ​ 7,133 Total ​ $ 21,912 ​ $ (5,187) ​ $ 16,725 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of October 31, 2022 Gross Amount Accumulated Amortization Net Amount In-Process Research and Development ​ $ 9,592 ​ $ - ​ $ 9,592 Bridgeport PPA ​ ​ 12,320 ​ ​ (4,539) ​ ​ 7,781 Total ​ $ 21,912 ​ $ (4,539) ​ $ 17,373

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Apr. 30, 2023
Accrued Liabilities
Schedule of Accrued Liabilities	Accrued liabilities as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Accrued payroll and employee benefits (1) ​ $ 6,482 ​ $ 8,534 Accrued product warranty cost ​ ​ 314 ​ ​ 537 Accrued service agreement and PPA costs (2) ​ ​ 12,580 ​ ​ 11,340 Accrued legal, taxes, professional and other ​ ​ 3,497 ​ ​ 7,004 Accrued liabilities ​ $ 22,873 ​ $ 27,415 (1) The balance in this account represents accrued payroll, payroll taxes and accrued bonus for both periods. The decrease in the account relates to a decrease in accrued bonus as of April 30, 2023 due to the payout in January 2023 of bonuses earned under the 2022 Management Incentive Plan. (2) Accrued service agreement costs include loss accruals on service agreements of $ 7.2 million and $7.3 million as of April 30, 2023 and October 31, 2022, respectively. The accruals for performance guarantees on service agreements and PPAs were $ 5.3 million and $4.1 million as of April 30, 2023 and October 31, 2022.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Apr. 30, 2023
Leases
Summary of Undiscounted Maturities of Operating Lease and Finance Lease Liabilities	Undiscounted maturities of operating lease and finance lease liabilities as of April 30, 2023 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Operating Leases Finance Leases Due Year 1 ​ $ 1,185 ​ $ 41 Due Year 2 ​ ​ 1,353 ​ ​ — Due Year 3 ​ ​ 1,263 ​ ​ — Due Year 4 ​ ​ 1,294 ​ ​ — Due Year 5 ​ ​ 1,313 ​ ​ — Thereafter ​ ​ 13,303 ​ ​ — Total undiscounted lease payments ​ ​ 19,711 ​ ​ 41 Less imputed interest ​ ​ (9,674) ​ ​ (6) Total discounted lease payments ​ $ 10,037 ​ $ 35

Loss Per Share (Tables)

Loss Per Share (Tables)	6 Months Ended
	Apr. 30, 2023
Loss Per Share
Calculation of Basic and Diluted Loss Per Share	The calculation of basic and diluted loss per share was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended April 30, Six Months Ended April 30, ​ ​ 2023 ​ 2022 2023 ​ 2022 ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss attributable to FuelCell Energy, Inc. $ (34,303) ​ $ (30,217) ​ $ (52,925) ​ $ (70,841) ​ ​ Series B preferred stock dividends ​ (800) ​ ​ (800) ​ ​ (1,600) ​ ​ (1,600) ​ ​ Net loss attributable to common stockholders $ (35,103) ​ $ (31,017) ​ $ (54,525) ​ $ (72,441) ​ ​ Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average common shares outstanding – basic ​ 406,316,070 ​ ​ 372,615,824 ​ ​ 406,055,027 ​ ​ 369,626,543 ​ ​ Effect of dilutive securities (1) ​ - ​ ​ - ​ ​ - ​ ​ - ​ ​ Weighted average common shares outstanding – diluted ​ 406,316,070 ​ ​ 372,615,824 ​ ​ 406,055,027 ​ ​ 369,626,543 ​ ​ Net loss to common stockholders per share – basic $ (0.09) ​ $ (0.08) ​ $ (0.13) ​ $ (0.20) ​ ​ Net loss to common stockholders per share – diluted (1) $ (0.09) ​ $ (0.08) ​ $ (0.13) ​ $ (0.20) ​ ​ (1) Due to the net loss to common stockholders in each of the periods presented above, diluted loss per share was computed without consideration to potentially dilutive instruments as their inclusion would have been anti-dilutive. As of April 30, 2023 and 2022, potentially dilutive securities excluded from the diluted loss per share calculation are as follows:
Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ April 30, ​ ​ 2023 2022 ​ May 2017 Offering – Series C Warrants ​ ​ - ​ ​ 950,102 ​ Outstanding options to purchase common stock ​ ​ 18,291 ​ ​ 20,231 ​ Unvested Restricted Stock Units ​ ​ 7,039,970 ​ ​ 3,315,557 ​ 5% Series B Cumulative Convertible Perpetual Preferred Stock ​ ​ 37,837 ​ ​ 37,837 ​ Total potentially dilutive securities ​ ​ 7,096,098 ​ ​ 4,323,727 ​

Restricted Cash (Tables)

Restricted Cash (Tables)	6 Months Ended
	Apr. 30, 2023
Restricted Cash.
Summary of Allocation of Restricted Cash	The allocation of restricted cash is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Cash Restricted for Outstanding Letters of Credit (1) ​ $ 9,062 ​ $ 4,993 Cash Restricted for PNC Sale-Leaseback Transactions (2) ​ ​ 5,843 ​ ​ 5,010 Cash Restricted for Crestmark Sale-Leaseback Transactions (3) ​ ​ 2,897 ​ ​ 2,894 Bridgeport Fuel Cell Park Project Debt Service and Performance Reserves (4) ​ ​ 10,285 ​ ​ 8,746 Other ​ ​ 2,143 ​ ​ 1,346 Total Restricted Cash ​ ​ 30,230 ​ ​ 22,989 Restricted Cash and Cash Equivalents – Short-Term (5) ​ ​ (4,778) ​ ​ (4,423) Restricted Cash and Cash Equivalents – Long-Term ​ $ 25,452 ​ $ 18,566 (1) Letters of credit outstanding as of April 30, 2023 expire on various dates through December 2028. The increase from October 31, 2022 represents a letter of credit entered into for a project asset-specific gas contract. (2) Long and short-term reserve that was to be used primarily to fund future module exchanges for operating projects falling under PNC sale-leaseback transactions (which transactions were terminated following the end of the quarter). (3) Long and short-term reserve that is to be used primarily to fund future module exchanges and other performance obligations under Crestmark sale-leaseback transactions. (4) Long and short-term reserves for the Bridgeport Fuel Cell Park Project that were to be used to fund future module exchanges and other performance requirements (which reserves were released following the end of the quarter). (5) Short-term restricted cash and cash equivalents are amounts expected to be released and classified as unrestricted cash within twelve months of the balance sheet date.

Debt (Tables)

Debt (Tables)	6 Months Ended
	Apr. 30, 2023
Debt
Schedule of Debt	Debt as of April 30, 2023 and October 31, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ October 31, ​ 2023 2022 Connecticut Green Bank Loan ​ $ 4,800 ​ $ 4,800 Connecticut Green Bank Loan (Bridgeport Fuel Cell Project) ​ ​ 3,077 ​ ​ 3,507 Liberty Bank Term Loan Agreement (Bridgeport Fuel Cell Project) ​ ​ 4,340 ​ ​ 5,382 Fifth Third Bank Term Loan Agreement (Bridgeport Fuel Cell Project) ​ ​ 4,340 ​ ​ 5,382 Finance obligation for sale-leaseback transactions ​ ​ 56,961 ​ ​ 56,625 State of Connecticut Loan ​ ​ 7,342 ​ ​ 7,774 Finance lease obligations ​ ​ 35 ​ ​ 57 Deferred finance costs ​ ​ (977) ​ ​ (1,152) Total debt and finance obligations ​ ​ 79,918 ​ ​ 82,375 Current portion of long-term debt and finance obligations ​ ​ (13,289) ​ ​ (13,198) Long-term debt and finance obligations ​ $ 66,629 ​ $ 69,177

Benefit Plans (Tables)

Benefit Plans (Tables)	6 Months Ended
	Apr. 30, 2023
Benefit Plans
Schedule of Share-Based Compensation Reflected in Consolidated Statement of Operations and Comprehensive Loss	Share-based compensation was reflected in the Consolidated Statements of Operations and Comprehensive Loss as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended April 30, ​ Six Months Ended April 30, ​ 2023 2022 ​ 2023 2022 Cost of revenues ​ $ 413 ​ $ 185 ​ $ 747 ​ $ 338 Administrative and selling expense ​ ​ 2,320 ​ ​ 1,350 ​ ​ 4,262 ​ ​ 2,528 Research and development expense ​ ​ 363 ​ ​ 106 ​ ​ 659 ​ ​ 184 ​ ​ $ 3,096 ​ $ 1,641 ​ $ 5,668 ​ $ 3,050
Summary of RSA and RSU Activity	The following table summarizes our RSU activity for the six months ended April 30, 2023: ​ ​ ​ ​ ​ ​ ​ Restricted Stock Units ​ Shares Weighted-Average Fair Value Outstanding as of October 31, 2022 ​ ​ 2,520,881 ​ $ 7.93 Granted - PSUs ​ ​ 1,124,953 ​ ​ 5.50 Granted - time-vesting RSUs ​ ​ 3,781,370 ​ ​ 3.41 Vested ​ ​ (261,059) ​ ​ 7.03 Forfeited ​ ​ (64,056) ​ ​ 7.55 Outstanding as of January 31, 2023 ​ ​ 7,102,089 ​ $ 5.18 Granted - time-vesting RSUs ​ ​ 64,550 ​ ​ 3.29 Vested ​ ​ (84,669) ​ ​ 5.96 Forfeited ​ ​ (42,000) ​ ​ 3.65 Outstanding as of April 30, 2023 ​ ​ 7,039,970 ​ $ 5.16

Nature of Business and Basis _3

Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended	10 Months Ended
	May 19, 2023	Jul. 12, 2022	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2023	Oct. 31, 2022
Nature Of Business And Basis Of Presentation [Line Items]
Cash and cash equivalents, unrestricted			$ 246,844		$ 246,844	$ 246,844	$ 458,055
Investments - short-term			$ 76,400		$ 76,400	$ 76,400
Shares remaining under the plan			75,600,000		75,600,000	75,600,000
US Treasury Securities
Nature Of Business And Basis Of Presentation [Line Items]
US Treasury Notes purchased					$ 138,200
US Treasury Securities sold					63,300
Investments - short-term			$ 76,400		$ 76,400	$ 76,400	$ 0
Non-Recourse Project Financing Facility | Subsequent Event
Nature Of Business And Basis Of Presentation [Line Items]
Repayments of debt	$ 1,800
Unrestricted cash	46,100
Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Stock issued during period shares new issues			949,438	19,896,904
Common Stock | 2022 Open Market Sale Agreement | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC
Nature Of Business And Basis Of Presentation [Line Items]
Average sale price per share			$ 3.02		$ 3.02	$ 3.60
Gross proceeds from issuance of common stock			$ 2,900		$ 2,900	$ 70,000
Stock issued during period shares new issues			900,000		900,000	19,400,000
Shares remaining under the plan			75,600,000		75,600,000	75,600,000
Common Stock | 2022 Open Market Sale Agreement | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC | Maximum
Nature Of Business And Basis Of Presentation [Line Items]
Aggregate number of shares to be offered		95,000,000
Stock issued during period shares new issues		95,000,000
Liberty Bank, Fifth Third Bank and Connecticut Green Bank | Subsequent Event
Nature Of Business And Basis Of Presentation [Line Items]
Repayments of debt	11,400
Liberty Bank and Fifth Third Bank | Subsequent Event
Nature Of Business And Basis Of Presentation [Line Items]
Unrestricted cash	46,100
Funds Released from Restricted Cash	11,200
Liberty Bank and Fifth Third Bank | Non-Recourse Project Financing Facility | Subsequent Event
Nature Of Business And Basis Of Presentation [Line Items]
Funds Released from Restricted Cash	$ 11,200

Tax Equity Financing (Details)

Tax Equity Financing (Details) $ in Thousands

1 Months Ended

3 Months Ended

6 Months Ended

Dec. 16, 2022 USD ($) MW

Oct. 04, 2022 MW

Jul. 07, 2022 USD ($)

May 15, 2022 USD ($)

Dec. 13, 2021 USD ($)

Oct. 18, 2021

Aug. 04, 2021 USD ($)

Nov. 30, 2021 USD ($) MW

Aug. 31, 2021 USD ($) MW

Apr. 30, 2023 USD ($)

Apr. 30, 2022 USD ($)

Apr. 30, 2023 USD ($)

Apr. 30, 2022 USD ($)

Jan. 31, 2022 USD ($)

Dec. 31, 2021 USD ($)

Tax Equity Financing

Net income (loss) attributable to noncontrolling interests

$ 392

$ 91

$ (2,072)

$ (5,405)

Groton Project [Member]

Tax Equity Financing

Net income (loss) attributable to noncontrolling interests

40

0

2,900

0

East West Bank Partnership Flip Transaction

Tax Equity Financing

Capacity of plant | MW

7.4

Tax equity financing commitment

$ 12,000

$ 15,000

Tax equity financing, Aggregate fee

500

Tax equity financing, Withdrawal right, Percent of return of investment

101%

Initial draw

$ 3,000

Closing costs

800

Remaining amount of draw

$ 12,000

Fee for extension of commercial operation deadline

$ 400

Percentage of cash and tax allocations to be received

95%

East West Bank Partnership Flip Transaction | Groton Project [Member]

Tax Equity Financing

Tax equity financing, Aggregate fee

$ 500

REI Partnership Flip Transaction

Tax Equity Financing

Capacity of plant | MW

7.4

Tax equity financing commitment

$ 12,400

11,900

11,900

Amount of Refund

500

Amount of distribution

200

100

Initial draw

$ 3,200

Closing costs

$ 400

Remaining amount of draw

$ 9,200

$ 9,200

Legal and advisory fees

400

Net income (loss) attributable to noncontrolling interests

$ 400

$ 100

$ 800

$ (5,400)

Percentage of cash and tax allocations to be received

95%

Percentage of amount payable

10.30%

Amended and Restated PPA | Groton Project [Member]

Tax Equity Financing

Capacity of plant | MW

6

Capacity of plant due to Technical Improvement Plan | MW

7.4

Payment of amendment fee

$ 1,200

First Anniversary of Project Achieving Commercial Operations [Member] | East West Bank Partnership Flip Transaction

Tax Equity Financing

Tax equity financing commitment, Contributions

4,000

Second Anniversary of Project Achieving Commercial Operations [Member] | East West Bank Partnership Flip Transaction

Tax Equity Financing

Tax equity financing commitment, Contributions

4,000

Third Anniversary of Project Achieving Commercial Operations [Member] | East West Bank Partnership Flip Transaction

Tax Equity Financing

Tax equity financing commitment, Contributions

$ 4,000

Maximum | East West Bank Partnership Flip Transaction | Groton Project [Member]

Tax Equity Financing

Capacity of plant | MW

7.4

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2023 USD ($)	Apr. 30, 2022 USD ($)	Apr. 30, 2023 USD ($)	Apr. 30, 2022 USD ($)	Dec. 20, 2022 USD ($)	Dec. 19, 2022 USD ($)	Oct. 31, 2022 USD ($) item
Disaggregation Of Revenue [Line Items]
Percentage of electricity output provided to customers			100%
Contract asset	$ 41,900		$ 41,900				$ 20,700
Long-term	25,600		25,600				9,700
Contract liability	4,800		4,800				$ 25,400
Revenues	38,349	$ 16,384	75,422	$ 48,179
POSCO Energy Settlement Agreement
Disaggregation Of Revenue [Line Items]
Option to purchase additional warranty module units | item							14
Modules units, order placed | item							20
Revenues			9,100
Emre joint development agreement
Disaggregation Of Revenue [Line Items]
Revenues	2,500		2,500
Research costs reimbursement amount					$ 60,000	$ 50,000
Milestone payment received				5,000
Emre joint development agreement | Rotterdam Project
Disaggregation Of Revenue [Line Items]
Investment amount		$ 5,000		$ 5,000
Remaining balance	2,500		2,500
Service Agreements
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	73,700		73,700
Advanced Technologies Contracts
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	22,600		22,600
Groton Project
Disaggregation Of Revenue [Line Items]
Remaining performance obligations	$ 65,100		$ 65,100

Investments - Short-Term (Detai

Investments - Short-Term (Details) - U.S. Treasury Securities $ in Thousands	6 Months Ended
	Apr. 30, 2023 USD ($)
Investments in United States Treasury Securities
U.S. Treasury Securities purchased	$ 138,200
US Treasury Securities sold	63,300
Amortized cost	76,400
Gross unrealized losses	(17)
Fair value	$ 76,383
Weighted average yield to maturity	4.75%

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Inventories
Raw materials	$ 39,261	$ 30,624
Work-in-process	55,582	67,834
Inventories	94,843	98,458
Inventories - current	(87,294)	(90,909)
Inventories - long-term	$ 7,549	$ 7,549

Inventories - Components of I_2

Inventories - Components of Inventories (Parenthetical) (Details) - USD ($) $ in Millions	Apr. 30, 2023	Oct. 31, 2022
Inventories
Completed standard component and modules	$ 35.2	$ 54

Project Assets - Summary of Pro

Project Assets - Summary of Project Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Apr. 30, 2023	Oct. 31, 2022
Project Assets [Line Items]
Accumulated depreciation	$ (36,081)	$ (29,546)
Project Assets, net	237,151	232,886
Project Assets - Operating
Project Assets [Line Items]
Project Assets, gross	210,211	154,736
Project Assets - Operating, net	$ 174,130	125,190
Project Assets - Operating | Minimum
Project Assets [Line Items]
Project assets estimated useful life	4 years
Project Assets - Operating | Maximum
Project Assets [Line Items]
Project assets estimated useful life	20 years
Project Assets - Construction in progress
Project Assets [Line Items]
Project Assets, gross	$ 63,021	$ 107,696
Project Assets BOP And Site Construction
Project Assets [Line Items]
Project assets estimated useful life	20 years
Project Assets Modules | Minimum
Project Assets [Line Items]
Project assets estimated useful life	4 years
Project Assets Modules | Maximum
Project Assets [Line Items]
Project assets estimated useful life	7 years

Project Assets - Additional Inf

Project Assets - Additional Information (Details) $ in Millions	6 Months Ended	12 Months Ended
	Apr. 30, 2023 USD ($) project MW	Oct. 31, 2022 USD ($) project
Project Assets [Line Items]
Number of project assets | project	9	8
Long-term project assets construction in progress	$ 63	$ 107.7
Power Purchase Agreement
Project Assets [Line Items]
Sale leaseback transaction, net book value	$ 174.1	$ 125.2
Toyota Project
Project Assets [Line Items]
Power capacity under construction phase | MW	2.3

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022	Oct. 31, 2022
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 4,075		$ 4,075		$ 4,075
Intangible assets, net	16,725		16,725		$ 17,373
Bridgeport Fuel Cell, LLC
Goodwill And Intangible Assets [Line Items]
Amortization expenses	$ 300	$ 300	$ 600	$ 600

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Finite Lived Intangible Assets [Line Items]
Gross Amount	$ 21,912	$ 21,912
Accumulated Amortization	(5,187)	(4,539)
Net Amount	16,725	17,373
Bridgeport PPA
Finite Lived Intangible Assets [Line Items]
Gross Amount	12,320	12,320
Accumulated Amortization	(5,187)	(4,539)
Net Amount	7,133	7,781
In Process Research And Development
Finite Lived Intangible Assets [Line Items]
Gross Amount	9,592	9,592
Net Amount	$ 9,592	$ 9,592

Accrued Liabilities - Schedule

Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Accrued Liabilities
Accrued payroll and employee benefits	$ 6,482	$ 8,534
Accrued product warranty cost	314	537
Accrued service agreement and PPA costs	12,580	11,340
Accrued legal, taxes, professional and other	3,497	7,004
Accrued liabilities	$ 22,873	$ 27,415

Accrued Liabilities - Schedul_2

Accrued Liabilities - Schedule of Accrued Liabilities (Parenthetical) (Details) - USD ($) $ in Millions	Apr. 30, 2023	Oct. 31, 2022
Schedule Of Accrued Liabilities [Line Items]
Loss reserve on service agreements	$ 7.2	$ 7.3
Bridgeport Fuel Cell Project
Schedule Of Accrued Liabilities [Line Items]
Reserve for performance guarantees	$ 5.3	$ 4.1

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands, $ in Millions			3 Months Ended		6 Months Ended
	Feb. 20, 2023 ft²	Jan. 05, 2023 ft²	Apr. 30, 2023 USD ($)	Apr. 30, 2022 USD ($)	Apr. 30, 2023 USD ($)	Apr. 30, 2022 USD ($)	Apr. 30, 2023 CAD ($)	Apr. 30, 2023 USD ($)	Jan. 31, 2023 CAD ($)	Jan. 31, 2023 USD ($)	Oct. 31, 2022 USD ($)
Lessee Lease Description [Line Items]
Finance lease ROU assets								$ 40			$ 40
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]							Property, plant and equipment, net	Property, plant and equipment, net			Property, plant and equipment, net
Finance lease liability								$ 40			$ 40
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]							Current portion of long-term debt	Current portion of long-term debt			Current portion of long-term debt
Operating lease right-of-use assets, net								$ 8,917			$ 7,189
Operating lease liability								$ 10,037
Operating lease expense			$ 400	$ 400	$ 744	$ 779
Operating lease, weighted average remaining lease term							17 years	17 years
Operating lease, weighted average discount rate							6.95%	6.95%
Operating lease, payments			$ 300	$ 300	$ 644	$ 730
Versa Power Systems, Ltd
Lessee Lease Description [Line Items]
Area of Additional Leased Space | ft²	18,627	48,000
Operating lease right-of-use assets, net							$ 0.2	$ 100	$ 2.7	$ 2,000
Operating lease liability							$ 0.2	$ 2,000	$ 2.7	$ 2,000

Leases - Summary of Undiscounte

Leases - Summary of Undiscounted Maturities of Operating Lease and Finance Lease Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Operating Leases
Due Year 1	$ 1,185
Due Year 2	1,353
Due Year 3	1,263
Due Year 4	1,294
Due Year 5	1,313
Thereafter	13,303
Total undiscounted lease payments	19,711
Less imputed interest	(9,674)
Total discounted lease payments	10,037
Finance Leases
Due Year 1	41
Total undiscounted lease payments	41
Less imputed interest	(6)
Total discounted lease payments	$ 35	$ 57
Finance Lease Liability Statement Of Financial Position Extensible List	Other Liabilities Noncurrent	Other Liabilities Noncurrent

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended	10 Months Ended
	Jul. 12, 2022	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2023
Stockholders' Equity Note
Shares remaining under the plan		75,600,000		75,600,000	75,600,000
Common Stock
Stockholders' Equity Note
Stock issued during period shares new issues		949,438	19,896,904
2022 Open Market Sale Agreement | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC
Stockholders' Equity Note
Percentage of sales commission	2%
2022 Open Market Sale Agreement | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC | Common Stock
Stockholders' Equity Note
Stock issued during period shares new issues		900,000		900,000	19,400,000
Gross proceeds from issuance of common stock		$ 2.9		$ 2.9	$ 70
Net proceeds from issuance of common stock		2.7		2.7	68
Payments of commissions		$ 0.2		$ 0.2	$ 2
Average sale price per share		$ 3.02		$ 3.02	$ 3.60
Shares remaining under the plan		75,600,000		75,600,000	75,600,000
2022 Open Market Sale Agreement | Maximum | Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canacord Genuity LLC, Citigroup Global Markets Inc., J.P. Morgan Securities LLC and Loop Capital Markets LLC | Common Stock
Stockholders' Equity Note
Stock issued during period shares new issues	95,000,000

Redeemable Preferred Stock (Det

Redeemable Preferred Stock (Details) - $ / shares	1 Months Ended
	Jan. 31, 2023	Mar. 31, 2005	Apr. 30, 2023
Class Of Stock [Line Items]
Preferred stock, par value			$ 0.01
Maximum
Class Of Stock [Line Items]
Preferred stock, shares authorized			250,000
Series B Preferred Stock
Class Of Stock [Line Items]
Preferred stock, shares authorized		105,875	105,875
Preferred stock, dividend rate, percentage	5%	5%

Redeemable Preferred Stock - Re

Redeemable Preferred Stock - Redeemable Series B Preferred Stock (Details) - Series B Preferred Stock - USD ($) $ / shares in Units, $ in Thousands	18 Months Ended
	Apr. 30, 2023	Oct. 31, 2022	Mar. 31, 2005
Class Of Stock [Line Items]
Preferred stock, shares authorized	105,875		105,875
Preferred stock, liquidation preference per share	$ 1,000
Preferred stock shares outstanding	64,020	64,020
Temporary equity, carrying amount, attributable to parent	$ 59,857	$ 59,857
Preferred stock, shares issued	64,020	64,020
Dividends, preferred stock, cash	$ 1,600

Loss Per Share - Calculation of

Loss Per Share - Calculation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Apr. 30, 2023	Jan. 31, 2023	Apr. 30, 2022	Jan. 31, 2022	Apr. 30, 2023	Apr. 30, 2022	Oct. 31, 2022
Numerator
Net loss attributable to FuelCell Energy, Inc.	$ (34,303)		$ (30,217)		$ (52,925)	$ (70,841)
Series B preferred stock dividends	(800)	$ (800)	(800)	$ (800)	(1,600)	(1,600)
Net loss attributable to common stockholders	$ (35,103)		$ (31,017)		$ (54,525)	$ (72,441)
Denominator
Weighted average common shares outstanding - basic	406,316,070		372,615,824		406,055,027	369,626,543	369,626,543
Weighted average common shares outstanding - diluted	406,316,070		372,615,824		406,055,027	369,626,543	369,626,543
Net loss to common stockholders per share - basic	$ (0.09)		$ (0.08)		$ (0.13)	$ (0.20)	$ (0.20)
Net loss to common stockholders per share - diluted	$ (0.09)		$ (0.08)		$ (0.13)	$ (0.20)	$ (0.20)
Series B Preferred Stock
Numerator
Series B preferred stock dividends	$ (800)		$ (800)		$ (1,600)	$ (1,600)

Loss Per Share - Schedule of Po

Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from the Diluted Loss Per Share Calculation (Details) - shares	1 Months Ended		6 Months Ended
	Jan. 31, 2023	Mar. 31, 2005	Apr. 30, 2023	Apr. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from diluted loss per share calculation			7,096,098	4,323,727
Series B Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Preferred stock, dividend rate, percentage	5%	5%
Series C Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from diluted loss per share calculation				950,102
Outstanding Options To Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from diluted loss per share calculation			18,291	20,231
Unvested Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from diluted loss per share calculation			7,039,970	3,315,557
5% Series B Cumulative Convertible Perpetual Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from diluted loss per share calculation			37,837	37,837

Restricted Cash - Additional In

Restricted Cash - Additional Information (Details) - USD ($) $ in Millions	Apr. 30, 2023	Oct. 31, 2022
Restricted Cash.
Restricted cash and cash equivalents	$ 30.2	$ 23

Restricted Cash - Summary of Al

Restricted Cash - Summary of Allocation of Restricted Cash (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Oct. 31, 2022
Restricted Cash.
Cash Restricted for Outstanding Letters of Credit	$ 9,062	$ 4,993
Cash Restricted for PNC Sale-Leaseback Transactions	5,843	5,010
Cash Restricted for Crestmark Sale-Leaseback Transaction	2,897	2,894
Bridgeport Fuel Cell Park Project Debt Service and Performance Reserves	10,285	8,746
Other	2,143	1,346
Total Restricted Cash	30,230	22,989
Restricted Cash and Cash Equivalents - Short-Term	(4,778)	(4,423)
Restricted cash and cash equivalents - long-term	$ 25,452	$ 18,566

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	May 19, 2023	Apr. 30, 2023	Oct. 31, 2022
Debt Instrument [Line Items]
Finance lease obligations		$ 35	$ 57
Finance Lease Liability Statement Of Financial Position Extensible List		Other Liabilities Noncurrent	Other Liabilities Noncurrent
Deferred finance costs		$ (977)	$ (1,152)
Total debt and finance obligations		79,918	82,375
Current portion of long-term debt and finance obligations		(13,289)	(13,198)
Long-term debt and finance obligations		66,629	69,177
Connecticut Green Bank Loan
Debt Instrument [Line Items]
Long-term Line of Credit		4,800	4,800
Connecticut Green Bank Loan (Bridgeport Fuel Cell Project)
Debt Instrument [Line Items]
Long-term Line of Credit		3,077	3,507
Liberty Bank Term Loan Agreement (Bridgeport Fuel Cell Project)
Debt Instrument [Line Items]
Long-term Line of Credit		4,340	5,382
Fifth Third Bank Term Loan Agreement (Bridgeport Fuel Cell Project)
Debt Instrument [Line Items]
Long-term Line of Credit		4,340	5,382
Finance obligation for sale-leaseback transactions
Debt Instrument [Line Items]
Long-term Line of Credit		56,961	56,625
State of Connecticut Loan
Debt Instrument [Line Items]
Long-term Line of Credit		$ 7,342	$ 7,774
Project Financing Facility | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments Of Debt	$ 1,800

Benefit Plans - Additional Info

Benefit Plans - Additional Information (Details)		3 Months Ended		6 Months Ended
	Dec. 05, 2022 item $ / shares shares	Apr. 30, 2023 shares	Jan. 31, 2023 shares	Apr. 30, 2023 D shares	Apr. 08, 2021 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Vested, Shares		84,669	261,059
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares			1,124,953
Percentage of Target Performance			100%
Time Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares		64,550	3,781,370
2018 Omnibus Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized					12,333,333
Common stock, shares available for issuance		3,517,296		3,517,296
Long Term Incentive Plan Fiscal 2023 [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of award components | item	2
Long Term Incentive Plan Fiscal 2023 [Member] | Senior Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares	2,249,890
Long Term Incentive Plan Fiscal 2023 [Member] | Relative Total Shareholder Return Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award Calibration Percentage				100%
Variance from Award Calibration Percentage				0.50%
Award Cap, Percent				200%
Award Additional Cap, Percent				100%
Threshold Consecutive Trading Days | D				60
Capital Shares reserved for future issuance		200%		200%
Long Term Incentive Plan Fiscal 2023 [Member] | Performance Shares | Senior Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares	1,124,953
Exercise price | $ / shares	$ 5.50
Long Term Incentive Plan Fiscal 2023 [Member] | Time Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of warrants vesting			33.33%	33.33%
Long Term Incentive Plan Fiscal 2023 [Member] | Time Based Awards | Senior Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares	1,124,937
Long Term Incentive Plan Fiscal 2023 [Member] | Time Based Awards | Salaried Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares				2,720,983
Long Term Incentive Plan Fiscal 2023 [Member] | Performance and Time Based Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock based compensation period	3 years
Maximum | 2018 Omnibus Incentive Plan | Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares reserved for issuance		2,036,257		2,036,257

Benefit Plans - Schedule of Sha

Benefit Plans - Schedule of Share-Based Compensation Reflected in Consolidated Statement of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 3,096	$ 1,641	$ 5,668	$ 3,050
Costs of Revenues
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	413	185	747	338
Administrative and Selling Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	2,320	1,350	4,262	2,528
Research and Development Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Allocated Share-based Compensation Expense	$ 363	$ 106	$ 659	$ 184

Benefit Plans - Summary of RSA

Benefit Plans - Summary of RSA and RSU Activity (Details) - $ / shares	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Jan. 31, 2023	Apr. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Outstanding, Shares, Beginning Balance	7,102,089	2,520,881	2,520,881
Restricted Stock Awards and Units, Vested, Shares	(84,669)	(261,059)
Restricted Stock Awards and Units, Forfeited, Shares	(42,000)	(64,056)
Restricted Stock Awards and Units, Outstanding, Shares, Ending Balance	7,039,970	7,102,089	7,039,970
Restricted Stock Awards and Units, Outstanding, Weighted-Average Fair Value, Beginning Balance	$ 5.18	$ 7.93	$ 7.93
Restricted Stock Awards and Units, Vested, Weighted-Average Fair Value	5.96	7.03
Restricted Stock Awards and Units, Forfeited, Weighted-Average Fair Value	3.65	7.55
Restricted Stock Awards and Units, Outstanding, Weighted-Average Fair Value, Ending Balance	$ 5.16	$ 5.18	$ 5.16
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares		1,124,953
Restricted Stock Awards and Units, Granted, Weighted-Average Fair Value		$ 5.50
Time Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted Stock Awards and Units, Granted, Shares	64,550	3,781,370
Restricted Stock Awards and Units, Granted, Weighted-Average Fair Value	$ 3.29	$ 3.41

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended		30 Months Ended
	Apr. 30, 2023 USD ($)	Apr. 30, 2022 USD ($)	Apr. 30, 2023 USD ($) project MW	Apr. 30, 2022 USD ($)	Apr. 30, 2023 USD ($)	Oct. 31, 2022 USD ($)
Commitments And Contingencies [Line Items]
Fuel Supply Contract Term			2 years
Total number of projects | project			3
Impairment charges	$ 4,500	$ 4,400	$ 11,600	$ 7,200	$ 36,400
Long Term Project Assets	237,151		237,151		237,151	$ 232,886
Recorded unconditional purchase obligation	100,800		$ 100,800		100,800
Tulare Biomart Project
Commitments And Contingencies [Line Items]
Term for procuring fuel			20 years
LIPA project
Commitments And Contingencies [Line Items]
Term for procuring fuel			7 years
LIPA project | Maximum
Commitments And Contingencies [Line Items]
Term for procuring fuel			18 years
Toyota Project
Commitments And Contingencies [Line Items]
Term for procuring fuel			2 years
Long Term Project Assets	22,100		$ 22,100		22,100
Toyota Project | Maximum
Commitments And Contingencies [Line Items]
Term for procuring fuel			20 years
Derby Project
Commitments And Contingencies [Line Items]
Term for procuring fuel			2 years
Derby Project | Maximum
Commitments And Contingencies [Line Items]
Term for procuring fuel			20 years
Derby Project 14.0 Mega Watt
Commitments And Contingencies [Line Items]
Under construction power plant capacity | MW			14
Long Term Project Assets	39,900		$ 39,900		39,900
Derby Project 2.8 Mega Watt
Commitments And Contingencies [Line Items]
Under construction power plant capacity | MW			2.8
Long Term Project Assets	$ 600		$ 600		$ 600
Bridgeport
Commitments And Contingencies [Line Items]
Operating power plant capacity | MW			14.9

Subsequent Events (Details)

Subsequent Events (Details)			1 Months Ended
	May 22, 2023 shares	May 19, 2023 USD ($) project	Apr. 30, 2024	Apr. 30, 2023 USD ($) position	Apr. 08, 2021 shares
2018 Omnibus Incentive Plan
Subsequent Events
Number of shares authorized | shares					12,333,333
State of Connecticut Loan | Third Amendment
Subsequent Events
Number of consecutive months maintain full time positions				24 months
Number of minimum full time positions required to be maintained | position				91
Number of minimum full time positions required to be maintained including additional employment positions | position				629
Additional credits to be earned				$ 2,000,000
Consecutive term for average number of employees			24 months	24 months
Principal payable number of employee under employee obligation target				$ 14,225
State of Connecticut Loan | Employment Obligation [Member] | Third Amendment
Subsequent Events
Number of minimum full time positions required to be maintained | position				538
Subsequent Event [Member]
Subsequent Events
Term to maintain debt service coverage ratio		6 months
Notional amount of hedge	100%
Interest rate	3.716%
Qurterly principal payment		$ 675,000
Granted | shares	0
Subsequent Event [Member] | First four years
Subsequent Events
Interest rate	6.366%
Subsequent Event [Member] | Thereafter
Subsequent Events
Interest rate	6.866%
Subsequent Event [Member] | Liberty Bank, Fifth Third Bank and Connecticut Green Bank
Subsequent Events
Repayments of debt		11,400,000
Subsequent Event [Member] | Liberty Bank and Fifth Third Bank
Subsequent Events
Funds released from restricted cash		11,200,000
Unrestricted cash		46,100,000
Subsequent Event [Member] | PNC Energy Capital, LLC
Subsequent Events
Funds released from restricted and unrestricted reserve account		$ 7,300,000
Subsequent Event [Member] | Minimum
Subsequent Events
Notional amount of hedge		75%
Subsequent Event [Member] | Maximum
Subsequent Events
Notional amount of hedge		105%
Subsequent Event [Member] | Maximum | 2018 Omnibus Incentive Plan
Subsequent Events
Additional number of shares authorized | shares	6,000,000
Number of shares authorized | shares	18,333,333
Shares to be issued on exercise of stock options | shares	1,833,333
Subsequent Event [Member] | Maximum | Employee Stock Purchase Plan
Subsequent Events
Additional number of shares authorized | shares	500,000
Number of shares authorized | shares	541,667
Number of shares that can be purchased by individual participant | shares	1,000
Subsequent Event [Member] | Project Financing Facility
Subsequent Events
Number of operating fuel cell generation projects | project		6
Number of leased projects ownership reacquired | project		3
Repayments of debt		$ 1,800,000
Payments of debt issuance costs		2,900,000
Net proceeds from debt		77,600,000
Payments for lease buyouts and sales taxes		15,000,000
Payments to fund capital expenditure reserve account		14,500,000
Proceeds from debt, distributed to company		34,900,000
Unrestricted cash		$ 46,100,000
Initial interest period		3 months
Principal amortization period		17 years
Debt service coverage ratio		1.30%
Debt instrument term		7 years
Capital Expenditure Reserve		$ 29,000,000
Future capital expenditures or long-term capital investments		29,000,000
Capital expenditure reserve funded out of debt		$ 14,500,000
Threshold annual operating expense budget as percent of base case model, approval from lenders		115%
Trailing period for debt service coverage ratio		12 months
Debt service coverage ratio, testing frequency		6 months
Subsequent Event [Member] | Project Financing Facility | Applicable interest period one
Subsequent Events
Interest period		1 month
Subsequent Event [Member] | Project Financing Facility | Applicable interest period two
Subsequent Events
Interest period		3 months
Subsequent Event [Member] | Project Financing Facility | Applicable interest period three
Subsequent Events
Interest period		6 months
Subsequent Event [Member] | Project Financing Facility | SOFR rate
Subsequent Events
Initial interest period		3 months
Subsequent Event [Member] | Project Financing Facility | SOFR rate | First four years
Subsequent Events
Interest rate, basis points		2.50%
Subsequent Event [Member] | Project Financing Facility | SOFR rate | Thereafter
Subsequent Events
Interest rate, basis points		3%
Subsequent Event [Member] | Project Financing Facility | Base rate | First four years
Subsequent Events
Interest rate, basis points		1.50%
Subsequent Event [Member] | Project Financing Facility | Base rate | Thereafter
Subsequent Events
Interest rate, basis points		2%
Subsequent Event [Member] | Project Financing Facility | Liberty Bank and Fifth Third Bank
Subsequent Events
Funds released from restricted cash		$ 11,200,000
Subsequent Event [Member] | Project Financing Facility | PNC Energy Capital, LLC
Subsequent Events
Number of leased projects ownership reacquired | project		3
Subsequent Event [Member] | Project Financing Facility | Bridgeport Fuel Cell Project [Member] | Liberty Bank, Fifth Third Bank and Connecticut Green Bank
Subsequent Events
Encumbrance amount		$ 11,400,000
Subsequent Event [Member] | Project Financing Facility | Pfizer Project | PNC Energy Capital, LLC | Sale-leaseback Arrangements with PNC
Subsequent Events
Lease buyout amount		15,700,000
Subsequent Event [Member] | Project Financing Facility | Riverside Regional Water Quality Control Plant Project | PNC Energy Capital, LLC | Sale-leaseback Arrangements with PNC
Subsequent Events
Lease buyout amount		3,700,000
Subsequent Event [Member] | Project Financing Facility | Santa Rita Jail Project | Sale-leaseback Arrangements with PNC
Subsequent Events
Lease buyout amount		$ 2,800,000
Subsequent Event [Member] | Project Financing Facility | LIPA Yaphank Solid Waste Management Project [Member]
Subsequent Events
Extension term of gas agreement		3 years
Period to exercise option to purchase member interest in tax equity partnership		6 months
Subsequent Event [Member] | Project Financing Facility | Minimum
Subsequent Events
Debt service coverage ratio		1.20%
Annual operating expense budget approval from lenders, lending percent		50%
Subsequent Event [Member] | Term loan
Subsequent Events
Debt Instrument, Face Amount		$ 80,500,000
Funds released from restricted and unrestricted reserve account		7,300,000
Gross proceeds from debt		80,500,000
Subsequent Event [Member] | Letter of credit
Subsequent Events
Line of credit facility, maximum borrowing capacity		$ 6,500,000