Subsequent Events	12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]
Subsequent Events	16. SUBSEQUENT EVENTS On March 6, 2026, OPAL Fuels LLC entered into a subscription agreement with Preferred Fuels LLC, (“Preferred Fuels”), an affiliate of Fortistar, pursuant to which Preferred Fuels committed to purchase up to $180,000 of Series A preferred units in multiple closings. At the initial closing on March 6, 2026, the investor purchased 1.2 million preferred units for aggregate proceeds of $120,000. OPAL Fuels may, in its sole discretion, require the investor to fund up to an additional $60,000 within one year of the initial closing, subject to the terms of the subscription agreement. The Series A preferred units are entitled to preferred quarterly distributions at a rate of 12% per annum, compounding quarterly, and rank senior to all other classes of equity interests of OPAL Fuels LLC, except for certain existing preferred units to which they are pari passu. In connection with the initial closing, the Company also issued a warrant to the investor to purchase up to 3.0 million shares of the Company’s Class A common stock, subject to vesting, forfeiture, and other terms and conditions. During the fourth quarter of 2025, Nextera provided notice of its right to require redemption of all outstanding Series A preferred units. The redemption period, originally scheduled to expire on March 3, 2026 was extended through March 31, 2026. On March 6, 2026, OPAL Fuels LLC redeemed all such preferred units for an aggregate redemption price of $100,000, funded with proceeds from the initial preferred unit issuance described above. In addition, subsequent to December 31, 2025, the Company drew approximately $128,400 under its term loan facility pursuant to its existing credit agreement. A portion of the proceeds from the borrowing was used to repay approximately $20,000 outstanding under the revolving loan facility.

Subsequent Events

12 Months Ended

Dec. 31, 2025

16. SUBSEQUENT EVENTS

On March 6, 2026, OPAL Fuels LLC entered into a subscription agreement with Preferred Fuels LLC, (“Preferred Fuels”), an affiliate of Fortistar, pursuant to which Preferred Fuels committed to purchase up to $180,000 of Series A preferred units in multiple closings. At the initial closing on March 6, 2026, the investor purchased 1.2 million preferred units for aggregate proceeds of $120,000. OPAL Fuels may, in its sole discretion, require the investor to fund up to an additional $60,000 within one year of the initial closing, subject to the terms of the subscription agreement.

The Series A preferred units are entitled to preferred quarterly distributions at a rate of 12% per annum, compounding quarterly, and rank senior to all other classes of equity interests of OPAL Fuels LLC, except for certain existing preferred units to which they are pari passu. In connection with the initial closing, the Company also issued a warrant to the investor to purchase up to 3.0 million shares of the Company’s Class A common stock, subject to vesting, forfeiture, and other terms and conditions.

During the fourth quarter of 2025, Nextera provided notice of its right to require redemption of all outstanding Series A preferred units. The redemption period, originally scheduled to expire on March 3, 2026 was extended through March 31, 2026. On March 6, 2026, OPAL Fuels LLC redeemed all such preferred units for an aggregate redemption price of $100,000, funded with proceeds from the initial preferred unit issuance described above.

In addition, subsequent to December 31, 2025, the Company drew approximately $128,400 under its term loan facility pursuant to its existing credit agreement. A portion of the proceeds from the borrowing was used to repay approximately $20,000 outstanding under the revolving loan facility.