Intangible Assets

3 Months Ended

Mar. 31, 2024

Intangible Assets

Intangible Assets

7. Intangible Assets

The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of March 31, 2024 were as follows (in thousands):

	Weighted Average	Gross Carrying		Accumulated
	Amortization Period	Amount		Amortization		Total
Acquired technology	14 years	$	102,880	$	(21,979)	$	80,901
Dry stack electrolyzer technology	10 years		29,000		(6,042)		22,958
Customer relationships, trade name and other	13 years		103,002		(23,536)		79,466
		$	234,882	$	(51,557)	$	183,325

The gross carrying amount and accumulated amortization of the Company’s acquired identifiable intangible assets as of December 31, 2023 were as follows (in thousands):

	Weighted Average	Gross Carrying		Accumulated
	Amortization Period	Amount		Amortization		Total
Acquired technology	14 years	$	103,060	$	(20,204)	$	82,856
Dry stack electrolyzer technology	10 years		29,000		(5,317)		23,683
Customer relationships, trade name and other	13 years		103,981		(21,634)		82,347
		$	236,041	$	(47,155)	$	188,886

The change in the gross carrying amount of the acquired technology and customer relationships, trade name and other from December 31, 2023 to March 31, 2024 was due to changes in foreign currency translation.

Amortization expense for acquired identifiable intangible assets for the three months ended March 31, 2024 and 2023 was $4.4 million and $5.0 million, respectively.

The estimated amortization expense for subsequent years is as follows (in thousands):

Remainder of 2024	$	14,132
2025		18,070
2026		16,487
2027		16,480
2028		16,071
2029 and thereafter		102,085
Total	$	183,325