Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 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):

	Three months ended				Six months ended
	June 30, 2024		June 30, 2023		June 30, 2024		June 30, 2023
Cost of sales	$	2,079	$	2,439	$	4,085	$	5,116
Research and development		2,251		1,765		4,593		4,047
Selling, general and administrative		18,416		32,657		24,440		67,886
	$	22,746	$	36,861	$	33,118	$	77,049

Nonvested Restricted Stock Shares Activity

The following table reflects the restricted common stock and restricted stock unit activity for the six months ended June 30, 2024 (in thousands except share amounts):

		Weighted		Aggregate
		Average Grant Date		Intrinsic
	Shares	Fair Value		Value
Unvested restricted stock at December 31, 2023	6,732,884	$	15.66	$	30,298
Granted	1,054,057		2.85		—
Vested	(573,045)		17.84		—
Forfeited	(931,081)		17.88		—
Unvested restricted stock at June 30, 2024	6,282,815	$	12.98	$	14,639

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, 2023	17,336,362	$	11.37		7.86	$	11,391
Options exercisable at December 31, 2023	8,288,944		11.84		6.18		7,250
Options unvested at December 31, 2023	9,047,418		10.94		9.39		4,141
Granted	4,968,125		2.51		—		—
Exercised	(32,500)		2.15		—		—
Forfeited	(2,018,782)		18.42		—		—
Options outstanding at June 30, 2024	20,253,205	$	8.51		7.53	$	464
Options exercisable at June 30, 2024	7,954,524		11.15		5.66		464
Options unvested at June 30, 2024	12,298,681	$	6.80		8.75	$	—

Performance Stock Option 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, 2023	21,925,000	$	21.32	5.27	$	—
Options exercisable at December 31, 2023	2,782,000		26.9	4.7		—
Options unvested at December 31, 2023	19,143,000		20.50	5.35		—
Granted	2,452,500		2.41	6.82		—
Exercised	—		—	—		—
Forfeited	(2,250,000)		—	—		—
Options outstanding at June 30, 2024	22,127,500	$	19.33	4.94	$	—
Options exercisable at June 30, 2024	4,038,667		20.99	4.74		—
Options unvested at June 30, 2024	18,088,833	$	18.96	4.98	$	—