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opal-202603160001842279FALSE00018422792026-03-162026-03-16

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 16, 2026

OPAL Fuels Inc. (Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578357 (IRS Employer Identification No.)

One North Lexington Avenue, Suite 1450 White Plains, New York 10601

(Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code: (914) 705-4000

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol(s) Name of each exchange on which registered

Class A common stock, par value $0.0001 per share

OPAL

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company    ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02. Results of Operations and Financial Condition

On March 16, 2026, OPAL Fuels Inc. (the "Company") issued a press release regarding its financial results for the year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto.

The information disclosed under this Item 2.02 of this Current Report on Form 8-K, including the exhibit, is being "furnished" and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of such section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. By filing this Current Report on Form 8-K and furnishing this information, the Company makes no statement or admission as to the materiality of any information in this Item 2.02 or the exhibit attached hereto.

This Current Report on Form 8-K, including the exhibit, contains forward-looking statements within the meaning of the federal securities laws. These forward looking statements are based on current expectations and are not guarantees of future performance. Further, the forward-looking statements are subject to the limitations listed in Exhibit 99.1 and in the other SEC reports of the Company, including that actual events or results may differ materially from those in the forward-looking statements.

Additionally, to supplement the Company’s financial statements presented in accordance with accounting principles generally accepted in the United States of America ("GAAP") in Exhibit 99.1, the Company uses a non-GAAP financial measure that it calls adjusted EBITDA ("Adjusted EBITDA"). This non-GAAP financial measure adjusts net income for interest and financing expense, net, net income attributable to non-redeemable non-controlling interests, depreciation, amortization and accretion, adjustments to reflect Adjusted EBITDA from equity method investments, fair value changes and non-recurring charges, stock-based compensation, major maintenance on Renewable Power, RNG development costs, and ITC proceeds, net. Management believes this non-GAAP financial measure provides meaningful supplemental information about the Company’s performance, for the following reasons: (1) it allows for greater transparency with respect to key metrics used by management to assess the Company’s operating performance and make financial and operational decisions; (2) the measure excludes the effect of items that management believes are not directly attributable to the Company’s core operating performance and may obscure trends in the business;

opal-202511060001842279FALSE00018422792025-11-062025-11-06

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 6, 2025

OPAL Fuels Inc. (Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578357 (IRS Employer Identification No.)

One North Lexington Avenue, Suite 1450 White Plains, New York 10601 (Address of principal executive offices) (Zip Code)

Registrant's telephone number, including area code: (914) 705-4000

Not Applicable (Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading Symbol(s) Name of each exchange on which registered

Class A common stock, par value $0.0001 per shareOPALThe Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company    ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02. Results of Operations and Financial Condition

On November 6, 2025, OPAL Fuels Inc. (the "Company") issued a press release regarding its financial results for the quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto.

The information disclosed under this Item 2.02 of this Current Report on Form 8-K, including the exhibit, is being "furnished" and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of such section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. By filing this Current Report on Form 8-K and furnishing this information, the Company makes no statement or admission as to the materiality of any information in this Item 2.02 or the exhibit attached hereto.

This Current Report on Form 8-K, including the exhibit, contains forward-looking statements within the meaning of the federal securities laws. These forward looking statements are based on current expectations and are not guarantees of future performance. Further, the forward-looking statements are subject to the limitations listed in Exhibit 99.1 and in the other SEC reports of the Company, including that actual events or results may differ materially from those in the forward-looking statements.

Additionally, to supplement the Company’s financial statements presented in accordance with accounting principles generally accepted in the United States of America ("GAAP") in Exhibit 99.1, the Company uses a non-GAAP financial measure that it calls adjusted EBITDA ("Adjusted EBITDA"). This non-GAAP financial measure adjusts net income for interest and financing expense, net, net income attributable to non-redeemable non-controlling interests, depreciation, amortization and accretion, adjustments to reflect Adjusted EBITDA from equity method investments, fair value changes and non-recurring charges, stock-based compensation, major maintenance on Renewable Power, RNG development costs, and ITC proceeds, net. Management believes this non-GAAP financial measure provides meaningful supplemental information about the Company’s performance, for the following reasons: (1) it allows for greater transparency with respect to key metrics used by management to assess the Company’s operating performance and make financial and operational decisions; (2) the measure excludes the effect of items that management believes are not directly attributable to the Company’s core operating performance and may obscure trends in the busin