Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2023

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):

	Three Months Ended				Nine Months Ended
	September 30, 2023		September 30, 2022		September 30, 2023		September 30, 2022
Cost of sales	$	3,115	$	1,821	$	8,231	$	4,928
Research and development		2,935		1,483		6,982		4,062
Selling, general and administrative		36,392		40,935		104,278		118,710
	$	42,442	$	44,239	$	119,491	$	127,700

Nonvested Restricted Stock Shares Activity

The following table reflects the restricted stock and restricted stock unit activity for the nine months ended September 30, 2023 (in thousands except share amounts):

		Weighted		Aggregate
		Average Grant Date		Intrinsic
	Shares	Fair Value		Value
Unvested restricted common stock and restricted stock units at December 31, 2022	6,276,376	$	21.56	$	77,639
Granted	3,606,393		12.57		—
Vested	(1,973,283)		20.77		—
Forfeited	(648,354)		23.50		—
Unvested restricted common stock and restricted stock units at September 30, 2023	7,261,132	$	17.14	$	55,185

Service Stock Options Awards

Schedule of Share-based Compensation, Stock Options, Activity

					Weighted
			Weighted		Average
			Average		Remaining		Aggregate
			Exercise		Contractual		Intrinsic
	Shares		Price		Terms		Value
Options outstanding at December 31, 2022	$	12,078,269	$	14.34	$	7.57	$	42,835
Granted		2,726,689		12.47		—		—
Exercised		(525,617)		2.50		—		—
Forfeited		(740,582)		28.01		—		—
Options outstanding at September 30, 2023	$	13,538,759	$	13.67	$	7.48	$	19,007
Options exercisable at September 30, 2023		7,850,918		10.98		6.20		19,007
Options unvested at September 30, 2023	$	5,687,841	$	17.39	$	9.24	$	—

Performance Stock Option Awards

Assumptions made for the purpose of estimating fair value

	Nine Months Ended
	September 30, 2023
Remaining VWAP performance period (years)	3
Risk-free interest rate	3.60%
Expected volatility	75.00%
Closing stock price on grant date	$ 7.87

Schedule of Share-based Compensation, Stock Options, Activity

				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
		Exercise		Contractual	Intrinsic
	Shares	Price		Terms	Value
Options outstanding at December 31, 2022	15,520,000	$	26.87	5.81	$	—
Granted	6,405,000		7.87	6.63		—
Options outstanding at September 30, 2023	21,925,000	$	21.32	5.52	$	—
Options exercisable at September 30, 2023	2,782,000		26.92	4.98		—
Options unvested at September 30, 2023	19,143,000	$	20.50	5.60	$	—