Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2024

Schedule of components and classification of stock-based compensation expense

The components and classification of stock-based compensation expense, excluding the Company’s matching contributions to the Plug Power Inc. 401(k) Savings & Retirement Plan and quarterly Board compensation, were as follows (in thousands):

	Year ended
	December 31, 2024		December 31, 2023		December 31, 2022
Cost of sales	$	7,252	$	11,079	$	7,259
Research and development		8,406		9,532		6,369
Selling, general and administrative		54,683		129,387		156,127
	$	70,341	$	149,998	$	169,755

Nonvested Restricted Stock Shares Activity

The following table reflects the restricted stock and restricted stock unit activity during the year ended December 31, 2024 (in thousands except share amounts):

		Weighted		Aggregate
		Average Grant Date		Intrinsic
	Shares	Fair Value		Value
Unvested restricted stock as of December 31, 2023	6,732,884	$	15.66	$	30,298
Granted	4,052,391		2.21		—
Vested	(2,746,700)		15.43		—
Forfeited	(1,288,203)		16.89		—
Unvested restricted stock as of December 31, 2024	6,750,372	$	7.44	$	14,378

Service Stock Options Awards

Assumptions made for the purpose of estimating fair value

	Year ended
	December 31, 2024	December 31, 2023	December 31, 2022
Expected term of options (years)	1 - 5	5	5
Risk free interest rate	3.48% - 4.63%	3.40% - 4.69%	1.26% - 4.34%
Volatility	85.00% - 97.82%	80.02% - 92.55%	73.38% - 85.97%

Schedule of Share-based Compensation, Stock Options, Activity

The following table reflects the Service Stock Option activity for the year ended December 31, 2024:

				Weighted
		Weighted		Average
		Average		Remaining		Aggregate
		Exercise		Contractual		Intrinsic
	Shares	Price		Terms		Value
Options outstanding as of December 31, 2023	17,336,362	$	11.37		7.86	$	11,391
Options exercisable as of December 31, 2023	8,288,944		11.84		6.18		7,250
Options unvested as of December 31, 2023	9,047,418		10.94		9.39		4,141
Granted	12,227,935		2.25		—		—
Exercised	(77,500)		13.40		—		—
Forfeited	(3,362,649)		15.35		—		—
Options outstanding as of December 31, 2024	26,124,148	$	6.62		7.74	$	735
Options exercisable as of December 31, 2024	9,965,432		10.99		5.90		166
Options unvested as of December 31, 2024	16,158,716	$	3.92		8.88	$	569

Market Condition Stock Option Awards

Assumptions made for the purpose of estimating fair value

	Year Ended	Year Ended	Year Ended
	December 31, 2024	December 31, 2023	December 31, 2022
Remaining VWAP performance period (years)	3	3	3
Risk-free interest rate	4.01% - 4.57%	3.60%	3.10%
Expected volatility	85.00% - 90.00%	75.00%	75.00%
Closing stock price on grant date	$2.41 - $2.47	$7.87	$26.38

Schedule of Share-based Compensation, Stock Options, Activity

The following table reflects the market condition stock options awards activity for the year ended December 31, 2024. Solely for the purposes of this table, the number of shares is based on participants earning the maximum number of shares underlying the market condition stock options awards (i.e., 200% of the target number of shares).

				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
		Exercise		Contractual	Intrinsic
	Shares	Price		Terms	Value
Options outstanding as of December 31, 2023	21,925,000	$	21.32	5.27	$	—
Options exercisable as of December 31, 2023	2,782,000		26.92	4.73		—
Options unvested as of December 31, 2023	19,143,000		20.50	5.35		—
Granted	2,952,500		2.42	—		—
Exercised	—		—	—		—
Forfeited	(12,311,500)		25.45	—		—
Options outstanding as of December 31, 2024	12,566,000	$	12.83	5.07	$	—
Options exercisable as of December 31, 2024	5,372,667		22.46	4.11		—
Options unvested as of December 31, 2024	7,193,333	$	5.63	5.78	$	—