Note 7. Restricted Marketable Securities (Notes)

12 Months Ended

Dec. 31, 2024

Debt Securities, Available-for-Sale, Restricted [Abstract]

7. Restricted Marketable Securities

Restricted marketable securities consisted of the following as of December 31, 2024 and 2023 (in thousands):


	2024		2023
U.S. debt	$	109,155	$	113,326
Foreign government obligations	49,024		51,229
Supranational debt	22,809		15,339
U.S. government obligations	18,148		18,416
Total restricted marketable securities	$	199,136	$	198,310

Our restricted marketable securities represent long-term investments to fund the estimated future cost of collecting and recycling modules covered under our solar module collection and recycling program. We have established a trust under which funds are put into custodial accounts with an established and reputable bank, for which First Solar, Inc.; First Solar Malaysia Sdn. Bhd.; and First Solar Manufacturing GmbH are grantors. As of December 31, 2024 and 2023, such custodial accounts also included noncurrent restricted cash and cash equivalents balances of $5.0 million and $6.2 million, respectively, which were reported within “Other assets.” Trust funds may be disbursed for qualified module collection and recycling costs (including capital and facility related recycling costs), payments to customers for assuming collection and recycling obligations, and reimbursements of any overfunded amounts. Investments in the trust must meet certain investment quality criteria comparable to highly rated government or agency bonds. As necessary, we fund any incremental amounts for our estimated collection and recycling obligations on an annual basis based on the estimated costs of collecting and recycling covered modules, estimated rates of return on our restricted marketable securities, and an estimated solar module life of 25 years, less amounts already funded in prior years. During the year ended December 31, 2024, we purchased $7.9 million of restricted marketable securities as part of our ongoing management of the custodial accounts.

See Note 12. “Fair Value Measurements” to our consolidated financial statements for information about the fair value of our restricted marketable securities.

The following tables summarize the unrealized gains and losses related to our restricted marketable securities, by major security type, as of December 31, 2024 and 2023 (in thousands):


	As of December 31, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
U.S. debt	$	144,652	$	—	$	35,497	$	—	$	109,155
Foreign government obligations	62,595		—		13,571		—		49,024
Supranational debt	25,351		—		2,542		—		22,809
U.S. government obligations	24,368		—		6,220		—		18,148
Total	$	256,966	$	—	$	57,830	$	—	$	199,136


	As of December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
U.S. debt	$	146,484	$	—	$	33,129	$	29	$	113,326
Foreign government obligations	65,202		—		13,963		10		51,229
U.S. government obligations	24,460		—		6,039		5		18,416
Supranational debt	17,688		—		2,349		—		15,339
Total	$	253,834	$	—	$	55,480	$	44	$	198,310

As of December 31, 2024, the contractual maturities of these securities were between 6 years and 15 years, and restricted marketable securities with unrealized losses had generally been in a loss position for a period of time greater than 12 months. The unrealized losses were primarily due to increases in interest rates relative to rates at the time of purchase, and based on the underlying credit quality of the investments, we expect to hold such securities until we recover our cost basis.