3. Restricted Marketable Securities (Notes)

9 Months Ended

Sep. 30, 2024

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

3. Restricted Marketable Securities

Restricted marketable securities consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Foreign government obligations	$	52,368	$	51,229
Supranational debt	23,350		15,339
U.S. debt	116,157		113,326
U.S. government obligations	19,255		18,416
Total restricted marketable securities	$	211,130	$	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 September 30, 2024 and December 31, 2023, such custodial accounts also included noncurrent restricted cash and cash equivalents balances of $4.5 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 nine months ended September 30, 2024, we purchased $7.9 million of restricted marketable securities as part of our ongoing management of the custodial accounts.

See Note 8. “Fair Value Measurements” to our condensed 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 September 30, 2024 and December 31, 2023 (in thousands):


	As of September 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
Foreign government obligations	$	65,336	$	—	$	12,968	$	—	$	52,368
Supranational debt	25,405		3		2,058		—		23,350
U.S. debt	145,113		—		28,956		—		116,157
U.S. government obligations	24,391		—		5,136		—		19,255
Total	$	260,245	$	3	$	49,118	$	—	$	211,130


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

As of September 30, 2024, the contractual maturities of these securities were between 6 years and 15 years.