OPAL / OPAL Fuels Inc. - SEC-Einreichungen, Jahresbericht, Proxy Statement

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): June 3, 2026 OPAL Fuels Inc. (Exa

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): June 3, 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) 80-09904

OPAL Fuels and GFL Environmental Advance Growth Strategy with New RNG Projects in Alabama and Georgia

OPAL Fuels and GFL Environmental Advance Growth Strategy with New RNG Projects in Alabama and Georgia New Projects Expected to Add Approximately 15 Million GGEs of RNG Supply Capacity WHITE PLAINS, N.

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): May 18, 2026 OPAL Fuels Inc. (Exa

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): May 18, 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) 98-15783

AMENDED AND RESTATED CERTIFICATE OF DESIGNATIONS OF SERIES A-1 PREFERRED UNITS OPAL FUELS LLC

Execution Version AMENDED AND RESTATED CERTIFICATE OF DESIGNATIONS OF SERIES A-1 PREFERRED UNITS OF OPAL FUELS LLC This Amended and Restated Certificate of Designations (this “Certificate of Designations”) of OPAL Fuels LLC, a limited liability company organized and existing under the laws of the State of Delaware (the “Company”), sets forth the relative rights, powers, privileges, limitations and

OPAL Fuels Reports First Quarter 2026 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports First Quarter 2026 Results WHITE PLAINS, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUEL

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): May 11, 2026 OPAL Fuels Inc. (Exa

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): May 11, 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) 98-15783

OPAL Fuels Announces First Quarter 2026 Earnings Release Date and Conference Call

OPAL Fuels Announces First Quarter 2026 Earnings Release Date and Conference Call WHITE PLAINS, N.

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): April 28, 2026 OPAL Fuels Inc. (E

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): April 28, 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) 98-157

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

FORM ARS

Annual Report 202 OP AL Fuels 202 Summary Annual Report and Form 10-KUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-40272 OPAL FUELS INC.

GUARANTY OPAL FUELS INC., a Delaware corporation, in favor of 2024 TTC AGGREGATOR, L.P., a Delaware limited partnership dated as of June 20, 2025 TABLE OF CONTENTS

Execution Version GUARANTY by OPAL FUELS INC., a Delaware corporation, in favor of 2024 TTC AGGREGATOR, L.P., a Delaware limited partnership dated as of June 20, 2025 TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS ...........................................................................................................1 1.1 Defined Terms ............................................................

PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW TAX CREDIT

Execution Version PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

Kazi Hasan Employment Proposal

Kazi Hasan Employment Proposal Position: Chief Financial Officer Target Starting Date: February 3rd, 2025 Location: White Plains, NY Base Salary: $500,000 annually, paid bi-weekly every other Friday.

PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW TAX CREDIT

Execution Version PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

OPAL Fuels Reports Fourth Quarter and Full Year 2025 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Fourth Quarter and Full Year 2025 Results WHITE PLAINS, N.

Subsidiaries of OPAL Fuels Inc. Entity Name Jurisdiction of Incorporation or Origination AC Landfill Energy LLC New Jersey Albany Energy LLC Delaware Arbor Hills Energy LLC Delaware Arbor Hills RNG LLC Delaware BC Landfill Energy LLC New Jersey Beaco

Subsidiaries of OPAL Fuels Inc. Entity Name Jurisdiction of Incorporation or Origination AC Landfill Energy LLC New Jersey Albany Energy LLC Delaware Arbor Hills Energy LLC Delaware Arbor Hills RNG LLC Delaware BC Landfill Energy LLC New Jersey Beacon HoldCo LLC Delaware Beacon Landfill Gas Holdings LLC Delaware Beacon RNG Acquisition LLC Delaware Beacon RNG Investments LLC Delaware Beacon RNG LLC

GUARANTY OPAL FUELS INC., a Delaware corporation, in favor of a Maryland charter commercial bank dated as of June 20, 2025 TABLE OF CONTENTS

Execution Version GUARANTY by OPAL FUELS INC., a Delaware corporation, in favor of EAGLEBANK, a Maryland charter commercial bank dated as of June 20, 2025 TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS ...........................................................................................................1 1.1 Defined Terms ........................................................................

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. (E

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) 98-157

OPAL FUELS INC., a Delaware corporation, in favor of 2024 TTC AGGREGATOR (B), L.P., a Delaware limited partnership ATHENE ANNUITY AND LIFE COMPANY, an Iowa corporation dated as of September 12, 2025 TABLE OF CONTENTS

Execution Version GUARANTY by OPAL FUELS INC., a Delaware corporation, in favor of 2024 TTC AGGREGATOR (B), L.P., a Delaware limited partnership and ATHENE ANNUITY AND LIFE COMPANY, an Iowa corporation dated as of September 12, 2025 TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS ...........................................................................................................1 1.1 Defined

PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW TAX CREDIT

Execution Version PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL.

OPAL Fuels Announces Closing of $180 Million Preferred Stock Facility

OPAL Fuels Announces Closing of $180 Million Preferred Stock Facility WHITE PLAINS, N.

AMENDED AND RESTATED CERTIFICATE OF DESIGNATIONS OF SERIES A PREFERRED UNITS OPAL FUELS LLC

Execution Copy AMENDED AND RESTATED CERTIFICATE OF DESIGNATIONS OF SERIES A PREFERRED UNITS OF OPAL FUELS LLC This Amended and Restated Certificate of Designations (this “Certificate of Designations”) of OPAL Fuels LLC, a limited liability company organized and existing under the laws of the State of Delaware (the “Company”), sets forth the relative rights, powers, privileges, limitations and rest

OPAL FUELS INC. Warrant To Purchase Class A Common Stock

Execution Copy WARRANT THE SECURITIES REPRESENTED BY THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS.

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 6, 2026 OPAL Fuels Inc. (Ex

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 6, 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) 98-1578

OPAL FUELS LLC SUBSCRIPTION AGREEMENT

Execution Copy OPAL FUELS LLC SUBSCRIPTION AGREEMENT Preferred Fuels LLC One North Lexington Avenue (14th Floor) White Plains, New York 10601 Ladies and Gentlemen: This Subscription Agreement (this “Subscription Agreement”) is being entered into as of March 6, 2026 (the “Execution Date”), by and between OPAL Fuels LLC, a Delaware limited liability company (the “Company”), and the undersigned subsc

OPAL Fuels Reports Third Quarter 2025 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Third Quarter 2025 Results WHITE PLAINS, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL

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.

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) 98-1

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): October 28, 2025 OPAL Fuels Inc.

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): October 28, 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) 98-1

OPAL Fuels Announces Appointment of Scott M. Sutton to its Board of Directors

OPAL Fuels Announces Appointment of Scott M. Sutton to its Board of Directors WHITE PLAINS, N.Y. – (DATE TBD) – OPAL Fuels (Nasdaq: OPAL) a leader in the production, marketing, and distribution of renewable and compressed natural gas (RNG and CNG) used as a transportation fuel for heavy-duty trucking, today announced the appointment of Scott M. Sutton to its Board of Directors, effective November

OPAL Fuels Announces Third Quarter 2025 Earnings Release Date and Conference Call

FOR IMMEDIATE RELEASE OPAL Fuels Announces Third Quarter 2025 Earnings Release Date and Conference Call WHITE PLAINS, N.

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): October 22, 2025 OPAL Fuels Inc.

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): October 22, 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) 98-1

OPAL Fuels Announces Appointment of Lance Moll to its Board of Directors

OPAL Fuels Announces Appointment of Lance Moll to its Board of Directors WHITE PLAINS, N.

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): September 29, 2025 OPAL Fuels Inc

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): September 29, 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

OPAL Fuels Reports Second Quarter 2025 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Second Quarter 2025 Results WHITE PLAINS, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUELS

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): August 7, 2025 OPAL Fuels Inc. (E

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): August 7, 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) 98-157

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): June 18, 2025 OPAL Fuels Inc. (Ex

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): June 18, 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) 98-1578

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUEL

First Amendment to Administrative Services Agreement, dated March 17, 2025 between Fortistar Services 2 LLC and OPAL Fuels LLC

Exhibit 10.4 FIRST AMENDMENT TO ADMINISTRATIVE SERVICES AGREEMENT THIS FIRST AMENDMENT (this “Amendment”), dated as of March 17, 2025 supplements and amends the Administrative Services Agreement, dated as of December 31, 2020 (hereinafter referred to, as amended, supplemented and modified from time to time in accordance with the terms thereof, together with all Exhibits attached or to be attached

imited Liability Company Agreeme

Exhibit 10.6 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LIMITED LIABILITY COMPANY AGREEMENT OF [***] This Limited Liability Company Agreement (this “Agreement”) of [***], a Delaware limited liability com

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 Commission File Number: 001-40272 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 Commission File Number: 001-40272 NOTIFICATION OF LATE FILING ☐ Form 10-K ☐ Form 20-F ☐ Form 11-K ☒ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: March 31, 2025 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Transition Report on Form 10-Q For

Option Agreement, dated March 17, 2025, between Wasatch RNG LLC and OPAL Fuels LLC

Exhibit 10.5 OPTION AGREEMENT This Option Agreement (this “Agreement”), dated March 17, 2025, is made and entered into by and between Wasatch RNG LLC, a Delaware limited liability company (“Wasatch RNG”), and OPAL Fuels LLC, a Delaware limited liability company (or one of its direct or indirect subsidiaries) (“Opal”). Each of the parties to this Agreement is sometimes individually referred to in t

OPAL Fuels Reports First Quarter 2025 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports First Quarter 2025 Results WHITE PLAINS, N.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 8, 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) 98-157835

FORM ARS

Annual Report 2024 OPAL Fuels 2024 Summary Annual Report and Form 10-KUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

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): April 21, 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) 98-157

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

OPAL Fuels Announces First Quarter 2025 Earnings Release Date and Conference Call

FOR IMMEDIATE RELEASE OPAL Fuels Announces First Quarter 2025 Earnings Release Date and Conference Call WHITE PLAINS, N.

Regulation FD Disclosure, Financial Statements and Exhibits

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): April 24, 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) 98-157

Financial Statements and Exhibits, Other Events

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): April 22, 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) 98-157

OPAL Fuels Announces Exchange of High-Voting Stock for Low-Voting Stock by Controlling Stockholder

FOR IMMEDIATE RELEASE OPAL Fuels Announces Exchange of High-Voting Stock for Low-Voting Stock by Controlling Stockholder WHITE PLAINS, N.

Tax Credit Purchase Agreement, dated March 28, 2025

Exhibit 10.1 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW TAX CREDIT PURCHASE AGREEMENT by and between APOLLO MANAGEMENT HOLDINGS, L.P. and OPAL PARAGON LLC Dated as of March 28, 2025 776104830 -1- TABLE O

Guaranty, dated March 28, 2025

Exhibit 10.2 GUARANTY by OPAL FUELS INC., a Delaware corporation, in favor of APOLLO MANAGEMENT HOLDINGS, L.P., a Delaware limited partnership dated as of March 28, 2025 TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS 1 1.1 Defined Terms 1 1.2 General Definitions 2 1.3 Rules of Interpretation 2 ARTICLE II. GUARANTY 2 2.1 Guaranty 2 2.2 Obligations Absolute and Unconditional 3 ARTICLE III. REPRESENTA

Financial Statements and Exhibits

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 28, 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) 98-157

to Exhibit 21.1 to the Annual Report on Form 10-K filed by the Company on March 1

Subsidiaries of OPAL Fuels Inc. Entity Name Jurisdiction of Incorporation or Origination AC Landfill Energy LLC New Jersey Albany Energy LLC Delaware Arbor Hills Energy LLC Delaware Arbor Hills RNG LLC Delaware Atlantic RNG LLC Delaware BC Landfill Energy LLC New Jersey Beacon HoldCo LLC Delaware Beacon Landfill Gas Holdings LLC Delaware Beacon RNG Acquisition LLC Delaware Beacon RNG Investments L

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-40272 OPAL FUELS INC.

Insider Trading Policy

INSIDER TRADING POLICY THIS POLICY WAS APPROVED BY THE BOARD ON JULY 22, 2022, revised August 17, 2022 1.

OPAL Fuels Reports Fourth Quarter and Full Year 2024 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Fourth Quarter and Full Year 2024 Results WHITE PLAINS, N.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 13, 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) 98-157

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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 3, 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) 98-1578

, 2025 by and among OPAL Fuels Intermediate HoldCo LLC, as Borrower, the Guarantors, the Lenders, the LC Issuers, and Bank of America, N.A., as Administrative Agent

Exhibit 10.1 AMENDMENT NO. 1 TO CREDIT AND GUARANTEE AGREEMENT This Amendment No. 1 to Credit and Guarantee Agreement (this “Agreement”) is entered into as of March 3, 2025, to be effective as of March 3, 2025, 2025 (the “Effective Date”) by and among OPAL FUELS INTERMEDIATE HOLDCO LLC, a Delaware limited liability company (the “Borrower”), each entity party hereto as a “Guarantor” (each individua

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): February 27, 2025 OPAL Fuels Inc.

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): February 27, 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-

OPAL Fuels Announces Fourth Quarter and Full Year 2024 Earnings Release Date and Conference Call

OPAL Fuels Announces Fourth Quarter and Full Year 2024 Earnings Release Date and Conference Call WHITE PLAINS, N.

JOINT FILING AGREEMENT

Invesco Joint Filing Agreement JOINT FILING AGREEMENT In accordance with Rule 13d-1(k) (l) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing of the attached Schedule 13G, and any and all amendments thereto, and expressly authorize Invesco Ltd.

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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): February 3, 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) 98-1

OPAL Fuels Appoints Kazi Hasan as Chief Financial Officer Proven energy industry executive brings over 25 years of extensive financial, operational, and strategic leadership experience in energy sector to drive disciplined growth and value creation

FOR IMMEDIATE RELEASE OPAL Fuels Appoints Kazi Hasan as Chief Financial Officer Proven energy industry executive brings over 25 years of extensive financial, operational, and strategic leadership experience in energy sector to drive disciplined growth and value creation WHITE PLAINS, N.

OPAL / OPAL Fuels Inc. / Encompass Capital Advisors LLC Passive Investment

SC 13G/A 1 encompass-opal093024a3.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 3)* Opal Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001 per share (Title of Class of Securities) 68347P103 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Ch

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL

OPAL / OPAL Fuels Inc. / VANGUARD GROUP INC Passive Investment

SC 13G/A 1 UnitedStates13GOPALFuelsI.txt 240.13d-102 Schedule 13G - Information to be included in statements filed pursuant to 240.13d-1(b), (c), and (d) and amendments thereto filed pursuant to 240.13d-2. Securities and Exchange Commission, Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* (Name of Issuer) OPAL Fuels Inc (Title of Class of Securities

OPAL / OPAL Fuels Inc. / Zimmer Partners, LP Passive Investment

SC 13G/A 1 formsc13gaopalfuels.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) (Amendment No. 2) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2 UNDER THE SECURITIES EXCHANGE ACT OF 1934 OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 7, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1

OPAL Fuels Reports Third Quarter 2024 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Third Quarter 2024 Results WHITE PLAINS, N.

OPAL / OPAL Fuels Inc. / VANGUARD GROUP INC Passive Investment

SC 13G/A 1 UnitedStates13GOPALFuelsI.txt 240.13d-102 Schedule 13G - Information to be included in statements filed pursuant to 240.13d-1(b), (c), and (d) and amendments thereto filed pursuant to 240.13d-2. Securities and Exchange Commission, Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* (Name of Issuer) OPAL Fuels Inc (Title of Class of Securities

OPAL / OPAL Fuels Inc. / VANGUARD GROUP INC Passive Investment

SC 13G/A 1 UnitedStates13GOPALFuelsI.txt 240.13d-102 Schedule 13G - Information to be included in statements filed pursuant to 240.13d-1(b), (c), and (d) and amendments thereto filed pursuant to 240.13d-2. Securities and Exchange Commission, Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* (Name of Issuer) OPAL Fuels Inc (Title of Class of Securities

Guaranty, dated September 13, 2024 (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by the Company on September 19, 2024).

Exhibit 10.2 GUARANTY by OPAL FUELS INC., a Delaware corporation, in favor of APOLLO MANAGEMENT HOLDINGS, L.P., a Delaware corporation dated as of September 13, 2024 Exhibit 10.2 TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS 1 1.1Defined Terms 1 1.2General Definitions 2 1.3Rules of Interpretation 2 ARTICLE II. GUARANTY 2 2.1 Guaranty 2 2.2 Obligations Absolute and Unconditional 3 ARTICLE III. REPR

OPAL Fuels Announces Agreement for $11.1 Million Sale of IRA Investment Tax Credits

Exhibit 99.1 FOR IMMEDIATE RELEASE OPAL Fuels Announces Agreement for $11.1 Million Sale of IRA Investment Tax Credits WHITE PLAINS, N.Y. – (September 18, 2024) – OPAL Fuels Inc. (Nasdaq: OPAL), a vertically integrated leader in the capture and conversion of biogas into low carbon intensity renewable natural gas (“RNG”) and renewable power, today announced the sale of approximately $11.1 million o

Financial Statements and Exhibits

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): September 13, 2024 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

Tax Credit Purchase Agreement, dated September 13, 2024 (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on September 19, 2024).

Exhibit 10.1 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW TAX CREDIT PURCHASE AGREEMENT by and between APOLLO MANAGEMENT HOLDINGS, L.P. and OPAL PARAGON LLC Dated as of September 13, 2024 Exhibit 10.1 TABL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUELS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment 1) (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-

OPAL Fuels Reports Second Quarter 2024 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Second Quarter 2024 Results WHITE PLAINS, N.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): August 7, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

OPAL Fuels Announces Second Quarter 2024 Earnings Release Date and Conference Call

OPAL Fuels Announces Second Quarter 2024 Earnings Release Date and Conference Call WHITE PLAINS, N.

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): July 25, 2024 OPAL Fuels Inc. (Ex

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): July 25, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

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): June 25, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

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): June 18, 2024 OPAL Fuels Inc. (Ex

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): June 18, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUEL

OPAL Fuels Reports First Quarter 2024 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports First Quarter 2024 Results WHITE PLAINS, N.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 9, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157835

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

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): April 25, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

OPAL Fuels Announces First Quarter 2024 Earnings Release Date and Conference Call

Draft 4-25-24 OPAL Fuels Announces First Quarter 2024 Earnings Release Date and Conference Call WHITE PLAINS, N.

ARS

Annual Report 2023 OPAL Fuels 2023 Summary Annual Report and Form 10-KUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

Lease and Access Agreement, dated March 27, 2024 (effective as of March 20, 2024)

, 2024) (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on March 2

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

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 27, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-40272 OPAL FUELS INC.

Clawback Policy

Revision Date – November 2023 OPAL FUELS INC. CLAWBACK POLICY I.Purpose and Scope The Board of Directors (the “Board”) of OPAL Fuels Inc. (the “Company”) believes that it is in the best interests of the Company and its shareholders to create and maintain a culture that emphasizes integrity and accountability and that reinforces the Company’s pay-for-performance compensation philosophy. The Board h

OPAL / OPAL Fuels Inc. / Comora Mark S - AMENDMENT NO. 1 TO SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1)* OPAL Fuels Inc. (Name of Issuer) Class A common stock, par value $0.0001 per share (Title of Class of Securities) 68347P 103 (CUSIP Number) Mark Comora c/o OPAL Fuels Inc. One North Lexington Avenue, Suite 1450 White Plains, New York 10601 (914) 705-4000

List of subsidiaries of the registrant.

Subsidiaries of OPAL Fuels Inc. Entity Name Jurisdiction of Incorporation or Origination AC Landfill Energy LLC New Jersey Albany Energy LLC Delaware Arbor Hills Energy LLC Delaware Arbor Hills RNG LLC Delaware Atlantic RNG LLC Delaware BC Landfill Energy LLC New Jersey Beacon HoldCo LLC Delaware Beacon Landfill Gas Holdings LLC Delaware Beacon RNG Acquisition LLC Delaware Beacon RNG Investments L

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 13, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

OPAL Fuels Reports Fourth Quarter and Full Year 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Fourth Quarter and Full Year 2023 Results WHITE PLAINS, N.

First Amendment to Depositary Agreement, dated March 5, 2024, by Paragon RNG LLC, as Borrower, Bank of Montreal, as administrative agent, and Wilmington Trust, National Association, as collateral agent and depositary agent (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by the Company on March 11, 2024).

Execution Version FIRST AMENDMENT TO DEPOSITARY AGREEMENT This FIRST AMENDMENT TO DEPOSITARY AGREEMENT, dated as of March 5, 2024 (this “Amendment”), is entered into by and among Paragon RNG LLC, a Delaware limited liability company (“Borrower”), Bank of Montreal, Chicago Branch, in its capacity as administrative agent (“Administrative Agent”), Wilmington Trust, National Association, in its capacity as collateral agent for the Secured Parties (“Collateral Agent”) and Wilmington Trust, National Association, in its capacity as depositary agent (“Depositary Agent”, and together with Borrower, Administrative Agent and Collateral Agent, each a “Party”, and collectively, the “Parties”) in connection with that certain Depositary Agreement.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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 5, 2024 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

First Amendment to Amended and Restated Credit and Guaranty Agreement, dated March 5, 2024, by and among Paragon RNG LLC, as Borrower, the guarantors, the lenders party thereto, and Bank of Montreal, as administrative agent (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on March 11, 2024).

Execution Version FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AND GUARANTY AGREEMENT THIS FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AND GUARANTY AGREEMENT (this “Amendment”), effective as of March 5, 2024 (the “First Amendment Effective Date”), is entered into by and among PARAGON RNG LLC, a Delaware limited liability company (the “Borrower”), the GUARANTORS named on the signature pages he

KY:OPAL / OPAL FUELS INC / Encompass Capital Advisors LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No.

KY:OPAL / OPAL FUELS INC / BARCLAYS PLC Passive Investment

SC 13G 1 OPALSC13G0224.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* OPAL Fuels Inc. (Name of Issuer) Common Stock, $0.0001 Par Value (Title of Class of Securities) 68347P103 (CUSIP Number) 29-Dec-23 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate th

AGREEMENT

EX-99.1 2 d660748dex991.htm EX-99.1 EXHIBIT 1 AGREEMENT The persons below hereby agree that the Schedule 13G to which this agreement is attached as an exhibit, as well as all future amendments to such Schedule 13G, shall be filed on behalf of each of them. This agreement is intended to satisfy the requirements of Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934. Date: February 14, 2

KY:OPAL / OPAL FUELS INC / Electron Capital Partners, LLC - SC 13G/A Passive Investment

SC 13G/A 1 d660748dsc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1) OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, $0.0001 par value per share (Title of Class of Securities) 68347P103 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) C

KY:OPAL / OPAL FUELS INC / VANGUARD GROUP INC - SCHEDULE 13G Passive Investment

SC 13G 1 tv01616-opalfuelsincclassa.htm SCHEDULE 13G SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 Name of issuer: OPAL Fuels Inc. Class A Title of Class of Securities: Common Stock CUSIP Number: 68347P103 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designate the rule pursua

KY:OPAL / OPAL FUELS INC / Zimmer Partners, LP Passive Investment

SC 13G/A 1 formsc13ga-opal.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) (Amendment No. 1) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2 UNDER THE SECURITIES EXCHANGE ACT OF 1934 OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001

KY:OPAL / OPAL FUELS INC / NEXTERA ENERGY INC Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 1)* OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001 per share (Title of Class of Securities) 68347P103 (CUSIP Number) Charles E. Sieving, Esq. Executive Vice President & General Counsel NextEra Energy, Inc. 700 Universe Boulevard Jun

KY:OPAL / OPAL FUELS INC / ArcLight CTC Holdings II, L.P. - AMENDMENT NO. 4 TO SCHEDULE 13D Activist Investment

SC 13D/A 1 ea190338-13da4arclight2opal.htm AMENDMENT NO. 4 TO SCHEDULE 13D UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 4)* OPAL FUELS INC. (Name of Issuer) Class A common stock, par value $0.0001 per share (Title of Class of Securities) 68347P 103 (CUSIP Number) Christine M. Miller c/o ArcLight CTC Ho

Regulation FD Disclosure, Financial Statements and Exhibits

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 22, 2023 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-

At Market Issuance Sales Agreement, dated November 17, 2023, among OPAL Fuels Inc., B. Riley Securities, Inc., Cantor Fitzgerald & Co. and Stifel, Nicolaus & Company, Incorporated (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on November 17, 2023).

Execution Version OPAL FUELS INC. Class A Common Stock (par value $0.0001 per share) At Market Issuance Sales Agreement November 17, 2023 B. Riley Securities, Inc. 299 Park Avenue, 21st Floor New York, NY 10171 Cantor Fitzgerald & Co. 110 East 59th Street New York, NY 10022 Stifel, Nicolaus & Company, Incorporated 787 7th Avenue 11th Floor New York, NY 10019 Ladies and Gentlemen: Opal Fuels Inc.,

Up to $75,000,000 OPAL FUELS INC. Class A Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-273584 PROSPECTUS SUPPLEMENT (To Prospectus dated September 6, 2023) Up to $75,000,000 OPAL FUELS INC. Class A Common Stock We have entered into an At Market Issuance Sales Agreement, dated November 17, 2023, (the “Sales Agreement”), with B. Riley Securities, Inc. (“B. Riley Securities”), Cantor Fitzgerald & Co. (“Cantor”) and Stifel, Nicolaus

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

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 17, 2023 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-

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) 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 13, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commiss

OPAL Fuels Reports Third Quarter 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Third Quarter 2023 Results WHITE PLAINS, N.

Base Contract for Sale and Purchase of Natural Gas (Richmond), dated September 15, 2023 (incorporated by reference to Exhibit 10.13 to the Quarterly Report on Form 10-Q filed by the Company on November 14, 2023).

Exhibit 10.13 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW Base Contract for Sale and Purchase of Natural Gas This Base Contract is entered into as of the following date: September 15, 2023. The parties to

Base Contract for Sale and Purchase of Natural Gas (San Diego), dated September 15, 2023 (incorporated by reference to Exhibit 10.12 to the Quarterly Report on Form 10-Q filed by the Company on November 14, 2023).

Exhibit 10.12 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW Base Contract for Sale and Purchase of Natural Gas This Base Contract is entered into as of the following date: September 15, 2023. The parties to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL

OPAL Fuels Reports Third Quarter 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Third Quarter 2023 Results WHITE PLAINS, N.

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 13, 2023 OPAL Fuels Inc.

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 13, 2023 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-

LETTER

United States securities and exchange commission logo November 2, 2023 Ann Anthony Chief Financial Officer OPAL Fuels Inc.

OPAL Fuels Announces Third Quarter 2023 Earnings Release Date and Conference Call

OPAL Fuels Announces Third Quarter 2023 Earnings Release Date and Conference Call WHITE PLAINS, N.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

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): October 30, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

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): October 20, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1

Asset Purchase and Sale Agreement, dated October 20, 2023, with Washington Gas Light Company (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on October 26, 2023).

Exhibit 10.1 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW Execution Version ASSET PURCHASE AND SALE AGREEMENT by and between PRINCE WILLIAM RNG LLC and WASHINGTON GAS LIGHT COMPANY Dated as of October , 20

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 5, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware 001-40272 98-1578357 (State or other jurisdiction of incorporation)

Separation Agreement and General Release dated October 19, 2023 between the Company and Ann Anthony (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K/A filed by the Company on October 20, 2023).

Exhibit 10.1 CONFIDENTIAL SEPARATION AGREEMENT AND GENERAL RELEASE This Confidential Separation Agreement and General Release (“Agreement”) is made by and between Ann Anthony (“Employee”) and OPAL Fuels Inc., a Delaware corporation (the “Company”). Employee and Company are herein after referred to as the “Parties,” and each a “Party.” WHEREAS, Employee has been employed by Company; WHEREAS, on Oct

2

Sheppard, Mullin, Richter & Hampton LLP 30 Rockefeller Plaza New York, New York 10112-0015 212.

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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): October 5, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-15

by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on October 12, 2023).

Execution Version OPAL FUELS LLC Interim Services Agreement This Interim Services Agreement (“Agreement”) is made as of October 12, 2023 (the “Effective Date”) by and between OPAL Fuels LLC, a Delaware limited liability company (the “Company”) and Fortistar Services 2 LLC, a Delaware limited liability company (the “Service Provider”).

OPAL Fuels Appoints Scott Contino Interim Chief Financial Officer

FOR IMMEDIATE RELEASE OPAL Fuels Appoints Scott Contino Interim Chief Financial Officer WHITE PLAINS, N.

Sheppard, Mullin, Richter & Hampton LLP

Sheppard, Mullin, Richter & Hampton LLP 30 Rockefeller Plaza New York, New York 10112-0015 212.

Agreement, dated September 14, 2023, by and among OPAL L2G and SJI (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on September 20, 2023).

Execution Version LIMITED LIABILITY COMPANY AGREEMENT OF LAND2GAS LLC THIS LIMITED LIABILITY COMPANY AGREEMENT (this “Agreement”) of Land2Gas LLC, a Delaware limited liability company (the “Company”), dated as of the 14th day of September, 2023 (the “Effective Date”), is by and between OPAL Land2Gas LLC, a Delaware limited liability company (“OPAL”), and SJI Landfill RNG LLC, a Delaware limited liability company (“SJI”), each as a Member of the Company.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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): September 14, 2023 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

LETTER

United States securities and exchange commission logo September 15, 2023 Ann Anthony Chief Financial Officer OPAL Fuels Inc.

Pledge Agreement, dated September 1, 2023, by OPAL Fuels Parent HoldCo 3 LLC in favor of Bank of America, N.A. (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by the Company on September 5, 2023).

Exhibit 10.2 Execution Version PLEDGE AGREEMENT dated as of September 1, 2023 of OPAL FUELS PARENT HOLDCO 3 LLC in favor of BANK OF AMERICA, N.A., as Collateral Agent ||||||||||| TABLE OF CONTENTS Page ARTICLE I Definitions and References 1 Section 1.1. Definitions in Credit Agreement 1 Section 1.2. Definitions in the UCC, etc 1 Section 1.3. Definitions in this Agreement 2 Section 1.4. Rules of Co

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

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): September 1, 2023 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-

Credit Agreement, dated September 1, 2023, by and among Intermediate HoldCo as Borrower, the guarantors, the lenders party thereto, Bank of America, N.A. as the administration agent, and Apterra Infrastructure Capital LLC, Barclays Bank PLC, BofA Securities, Inc., Celtic Bank Corporation, JP Morgan Chase Bank, N.A. and Investec Inc., as joint lead arrangers (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on September 5, 2023).

Exhibit 10.1 Deal CUSIP: 68347UAA0 Term Loan CUSIP: 68347UAB8 Revolving Loan CUSIP: 68347UAC6 CREDIT AND GUARANTEE AGREEMENT Dated as of September 1, 2023 among OPAL FUELS INTERMEDIATE HOLDCO LLC, as Borrower THE GUARANTORS PARTY HERETO FROM TIME TO TIME BANK OF AMERICA, N.A., as Administrative Agent APTERRA INFRASTRUCTURE CAPITAL LLC, BARCLAYS BANK PLC, BofA SECURITIES, INC., CELTIC BANK CORPORAT

OPAL Fuels Announces New $500 Million Credit Facility

OPAL Fuels Announces New $500 Million Credit Facility WHITE PLAINS, N.Y. – (September 5, 2023) – OPAL Fuels Inc. (Nasdaq: OPAL), a vertically integrated producer and distributor of renewable natural gas (RNG) and renewable electricity, announced today the closing of a new $500 million senior secured credit facility (the “Credit Facility”). The Credit Facility consolidates certain existing indebted

Security Agreement, dated September 1, 2023, by OPAL Fuels Intermediate HoldCo LLC and the other grantors listed on the signature pages thereto in favor of Bank of America, N.A. (incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed by the Company on September 5, 2023).

Exhibit 10.3 Execution Version SECURITY AGREEMENT dated as of September 1, 2023 of OPAL FUELS INTERMEDIATE HOLDCO LLC and each other Grantor listed on the signature pages hereof in favor of BANK OF AMERICA, N.A. as Collateral Agent ||||||||||| TABLE OF CONTENTS Page ARTICLE I Definitions and References 1 Section 1.1. Definitions in Credit Agreement 1 Section 1.2. Definitions in the UCC, etc 1 Sect

Note (Revolving), dated September 1, 2023, between OPAL Fuels Intermediate HoldCo LLC and BankUnited, N.A. (incorporated by reference to Exhibit 10.5 to the Current Report on Form 8-K filed by the Company on September 5, 2023).

Exhibit 10.5 NOTE $2,500,000 New York, New York No. 2 FOR VALUE RECEIVED, the undersigned, OPAL FUELS INTERMEDIATE HOLDCO LLC, a Delaware limited liability company (“Borrower”), hereby promises to pay to BANKUNITED, N.A. (“Lender”), the principal sum of TWO MILLION FIVE HUNDRED THOUSAND DOLLARS ($2,500,000), or, if less, the aggregate unpaid principal amount of the Revolving Loans made by Lender t

Note (Term), dated September 1, 2023, between OPAL Fuels Intermediate HoldCo LLC and BankUnited, N.A. (incorporated by reference to Exhibit 10.4 to the Current Report on Form 8-K filed by the Company on September 5, 2023).

Exhibit 10.4 NOTE $32,500,000 New York, New York No. 1 FOR VALUE RECEIVED, the undersigned, OPAL FUELS INTERMEDIATE HOLDCO LLC, a Delaware limited liability company (“Borrower”), hereby promises to pay to BANKUNITED, N.A. (“Lender”), the principal sum of THIRTY-TWO MILLION FIVE HUNDRED THOUSAND DOLLARS ($32,500,000), or, if less, the aggregate unpaid principal amount of the Term Loans made by Lend

OPAL Fuels Inc. One North Lexington Avenue, Suite 1450 White Plains, New York 10601 (914) 705-4000

OPAL Fuels Inc. One North Lexington Avenue, Suite 1450 White Plains, New York 10601 (914) 705-4000 September 1, 2023 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance Office of Energy & Transportation 100 F Street, N.E. Washington, D.C. 20549 Attention: Claudia Rodriguez Re: OPAL Fuels Inc. Registration Statement on Form S-3 File No. 333-273584 Ladies and G

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

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): August 28, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-15

Landfill Gas Purchase and Sale Agreement, dated August 28, 2023 with Waste Management of California, Inc. (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on August 31, 2023).

Exhibit 10.1 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LANDFILL GAS PURCHASE AND SALE AGREEMENT Between WASTE MANAGEMENT OF CALIFORNIA, INC. And KIRBY CANYON RNG, LLC Dated as of August 28 , 2023 LANDFI

Lease Agreement, dated August 28, 2023 with Guadalupe Rubbish Disposal Co., Inc. (incorporated by reference to Exhibit 10.4 to the Current Report on Form 8-K filed by the Company on August 31, 2023).

Exhibit 10.4 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LEASE AGREEMENT THIS LEASE AGREEMENT (this “Agreement”) made as of this 28th day of August , 2023 (the “Effective Date”) by and between Guadalupe R

Landfill Gas Purchase and Sale Agreement, dated August 28, 2023 with Guadalupe Rubbish Disposal Co., Inc. (incorporated by reference to Exhibit 10.3 to the Current Report on Form 8-K filed by the Company on August 31, 2023).

Exhibit 10.3 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LANDFILL GAS PURCHASE AND SALE AGREEMENT Between GUADALUPE RUBBISH DISPOSAL CO., INC. And GUADALUPE RENEWABLE ENERGY LLC Dated as of August 28 , 20

Lease Agreement, dated August 28, 2023 with Waste Management of California, Inc. (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by the Company on August 31, 2023).

Exhibit 10.2 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LEASE AGREEMENT THIS LEASE AGREEMENT (this “Agreement”) made as of this 28th day of August , 2023 (the “Effective Date”) by and between Waste Manag

Third Amended and Restated Gas Sale and Purchase Agreement, dated August 11, 2023 (incorporated by reference to Exhibit 10.5 to the Quarterly Report on Form 10-Q filed by the Company on August 14, 2023).

Exhibit 10.5 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW Execution Version THIRD AMENDED AND RESTATED GAS SALE AND PURCHASE AGREEMENT [***] and Fall River Renewable Power LLC 1 THIRD AMENDED AND RESTATED

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUELS

OPAL FUELS INC. UP TO 163,676,735 SHARES OF CLASS A COMMON STOCK

Filed pursuant to Rule 424(b)(3) Registration No. 333-266757 PROSPECTUS OPAL FUELS INC. UP TO 163,676,735 SHARES OF CLASS A COMMON STOCK This prospectus relates to the offer and sale from time to time by the selling securityholders named in this prospectus (the “Selling Holders”) of: (i) 8,202,865 shares of Class A common stock issued under the Business Combination Agreement, dated as of December

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables FORM S-3/A (Form Type) OPAL FUELS INC.

As filed with the Securities and Exchange Commission on August 11, 2023

As filed with the Securities and Exchange Commission on August 11, 2023 Registration No.

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): August 9, 2023 OPAL Fuels Inc. (E

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): August 9, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

OPAL Fuels Reports Second Quarter 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports Second Quarter 2023 Results WHITE PLAINS, N.

As filed with the Securities and Exchange Commission on August 1, 2023

As filed with the Securities and Exchange Commission on August 1, 2023 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables FORM S-3 (Form Type) OPAL FUELS INC. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price Per Share(1) Maximum Aggregate Offering Price(2) Fee Rate Amount of Registration Fee(3) Fees to Be Paid Equity Other

As filed with the Securities and Exchange Commission on August 1, 2023

As filed with the Securities and Exchange Commission on August 1, 2023 Registration No.

OPAL Fuels Announces Second Quarter 2023 Earnings Release Date and Conference Call

Exhibit 99.1 OPAL Fuels Announces Second Quarter 2023 Earnings Release Date and Conference Call WHITE PLAINS, N.Y. – (July 19, 2023) – OPAL Fuels Inc. (Nasdaq: OPAL), a vertically integrated producer and distributor of renewable natural gas (RNG) and renewable electricity, announced that it will release its earnings results for the second quarter ended June 30, 2023, after market close on Wednesda

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): July 19, 2023 OPAL Fuels Inc. (Ex

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): July 19, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

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): June 26, 2023 OPAL Fuels Inc. (Ex

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): June 26, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

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): June 23, 2023 OPAL Fuels Inc. (Ex

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): June 23, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

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): May 30, 2023 OPAL Fuels Inc. (Exa

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): May 30, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-15783

Amended and Restated Credit and Guaranty Agreement, dated May 30, 2023, among Paragon RNG LLC as Borrower, the Guarantors, the lenders thereto, Bank of Montreal as the administrative agent, Wilmington Trust as collateral agent and BMO Capital Markets Corp., Investec Inc. and Comerica Bank as joint lead arrangers (incorporated by reference to Exhibit 10.1 to the Current Report on Form 8-K filed by the Company on June 2, 2023).

Exhibit 10.1 AMENDED AND RESTATED CREDIT AND GUARANTY AGREEMENT dated as of May 30, 2023 among PARAGON RNG LLC, as Borrower, The Guarantors Party Hereto, as Guarantors, BANK OF MONTREAL, CHICAGO BRANCH, INVESTEC BANK PLC and COMERICA BANK, as Lenders, The LC Issuers and Other Lenders From Time to Time Party Hereto, BANK OF MONTREAL, CHICAGO BRANCH, as Administrative Agent, WILMINGTON TRUST, NATION

OPAL FUELS INC.

Prospectus Supplement No. 1 Filed pursuant to Rule 424(b)(3) (To Prospectus dated May 15, 2023) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated May 15, 2023 (the “Prospectus”), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospectus sup

Landfill Gas Purchase and Sale Agreement dated April 13, 2023 (effective as of March 13, 2023)

Exhibit 10.2 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW LANDFILL GAS PURCHASE AND SALE AGREEMENT Between WASTE MANAGEMENT OF ILLINOIS, INC. And COTTONWOOD RNG LLC Dated as of March 13, 2023 -1- LANDFILL

Piggyback Agreement for Landfill Gas Purchase Agreement dated May 2, 2023 (incorporated by reference to Exhibit 10.3 to the Quarterly Report on Form 10-Q filed by the Company on May 15, 2023).

Exhibit 10.3 PORTIONS OF INFORMATION CONTAINED IN THIS AGREEMENT HAVE BEEN EXCLUDED FROM THIS AGREEMENT BECAUSE THEY ARE BOTH NOT MATERIAL AND THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUDED INFORMATION IS MARKED AS [***] BELOW PIGGYBACK AGREEMENT FOR LANDFILL GAS PURCHASES THIS PIGGYBACK AGREEMENT (the “Agreement”), dated May 2, 2023 (the “Execution Date”), is entered int

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-40272 OPAL FUEL

PROSPECTUS OPAL FUELS INC. UP TO 166,318,246 SHARES OF CLASS A COMMON STOCK

Filed pursuant to Rule 424(b)(3) Registration Statement No. 333-266757 PROSPECTUS OPAL FUELS INC. UP TO 166,318,246 SHARES OF CLASS A COMMON STOCK This prospectus relates to the offer and sale from time to time by the selling securityholders named in this prospectus (the “Selling Holders”) of: (i) 10,838,609 shares of Class A common stock issued under the Business Combination Agreement, dated as o

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): May 10, 2023 OPAL Fuels Inc. (Exa

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): May 10, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-15783

OPAL Fuels Reports First Quarter 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports First Quarter 2023 Results WHITE PLAINS, N.

OPAL Fuels Reports First Quarter 2023 Results

FOR IMMEDIATE RELEASE OPAL Fuels Reports First Quarter 2023 Results WHITE PLAINS, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2023

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

ARS

Leadership for a Low Carbon Future 2022 ANNUAL REPORTVision Our vision is to transition to a world where energy is clean, air is safe, and the environment is secure for generations to come.

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): May 2, 2023 OPAL Fuels Inc. (Exac

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): May 2, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157835

As filed with the Securities and Exchange Commission on May 4, 2023

As filed with the Securities and Exchange Commission on May 4, 2023 Registration No.

As filed with the Securities and Exchange Commission on May 3, 2023

As filed with the Securities and Exchange Commission on May 3, 2023 Registration No.

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): April 28, 2023 OPAL Fuels Inc. (E

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): April 28, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

OPAL Fuels Announces First Quarter Earnings Release Date and Conference Call

OPAL Fuels Announces First Quarter Earnings Release Date and Conference Call WHITE PLAINS, N.

KY:OPAL / OPAL FUELS INC / ArcLight CTC Holdings II, L.P. - AMENDMENT NO. 3 TO SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 3)* OPAL FUELS INC. (Name of Issuer) Class A common stock, par value $0.0001 per share (Title of Class of Securities) 68347P 103 (CUSIP Number) Christine M. Miller c/o ArcLight CTC Holdings II, L.P. 200 Clarendon St, 55th Floor Boston, MA 02116 (617) 531-630

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): April 13, 2023 OPAL Fuels Inc. (E

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): April 13, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

KY:OPAL / OPAL FUELS INC / Meteora Capital, LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No.

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 30, 2023 OPAL Fuels Inc. (E

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 30, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

Securities Purchase Agreement, dated March 30, 2023, by and between OPAL Fuels Inc. and purchasers named therein (incorporated by reference to Exhibit 10.1 to the registrant's Current Report on Form 8-K filed with the SEC on April 5, 2023).

SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of March 30, 2023, by and among OPAL Fuels Inc.

Form of Stock Option Grant Notice and Option Agreement (incorporated by reference to the Annual Report on Form 10-K filed on March 28, 2023).

OPAL FUELS INC. STOCK OPTION GRANT NOTICE AND OPTION AGREEMENT (2022 Omnibus Equity Incentive Plan) As a key leader in our business, you are in a position to have significant influence on the performance and success of OPAL Fuels Inc. (the “Company”). I am pleased to inform you that, in recognition of the role you play in our collective success, you have been granted an option to purchase shares o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-40272 OPAL FUELS INC.

OPAL Fuels Inc. Short-Term Incentive Plan (incorporated by reference to Exhibit 4.4 to the Annual Report on Form 10-K filed on March 29, 2023).

OPAL FUELS INC. SHORT-TERM INCENTIVE PLAN ARTICLE 1PLAN OBJECTIVES Section 1.1Purpose. The purpose of the Plan is to achieve the following objectives: (i) recognize outstanding performers who have contributed significantly to the Company’s success and to the success of such performers’ respective business units, (ii) align corporate goals and strategy to executive compensation strategy, and (iii)

Form of Performance Restricted Stock Unit Award Grant Notice and Award Agreement (incorporated by reference to the Annual Report on Form 10-K filed on March 28, 2023).

OPAL FUELS INC. PERFORMANCE RESTRICTED STOCK UNIT AWARD GRANT NOTICE (2022 Omnibus Equity Incentive Plan) As a key leader in our business, you are in a position to have significant influence on the performance and success of OPAL Fuels Inc. (the “Company”). I am pleased to inform you that, in recognition of the role you play in our collective success, you have been granted a Performance Restricted

OPAL Fuels Reports Revenue of $235.5 million and 2.2 million MMBtu of RNG Produced in 2022, Representing 42% and 38% Annual Increases

FOR IMMEDIATE RELEASE OPAL Fuels Reports Revenue of $235.5 million and 2.2 million MMBtu of RNG Produced in 2022, Representing 42% and 38% Annual Increases WHITE PLAINS, N.Y. – (March 27, 2023) – OPAL Fuels Inc. (“OPAL Fuels” or the “Company”) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas (RNG), today announced financial and operating results for

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 27, 2023 OPAL Fuels Inc. (E

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 27, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-157

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 7, 2023 OPAL Fuels Inc. (Ex

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 7, 2023 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commission File Number) 98-1578

OPAL Fuels Announces Fourth Quarter and Full Year 2022 Earnings Release Date and Conference Call

OPAL Fuels Announces Fourth Quarter and Full Year 2022 Earnings Release Date and Conference Call WHITE PLAINS, N.

KY:OPAL / OPAL FUELS INC / Electron Capital Partners, LLC - SC 13G Passive Investment

SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, $0.0001 par value per share (Title of Class of Securities) 68347P103 (CUSIP Number) July 22, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

AGREEMENT

EX-99.1 EXHIBIT 1 AGREEMENT The persons below hereby agree that the Schedule 13G to which this agreement is attached as an exhibit, as well as all future amendments to such Schedule 13G, shall be filed on behalf of each of them. This agreement is intended to satisfy the requirements of Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934. Date: February 21, 2023 ELECTRON CAPITAL PARTNER

US68347P1030 / OPAL Fuels, Inc. / Meteora Capital, LLC - SC 13G Passive Investment

SC 13G 1 opal13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* OPAL Fuels Inc. (Name of Issuer) Class A Common stock, par value $0.0001 (Title of Class of Securities) 68347P103 (CUSIP Number) December 31, 2022 (Date of Event which Requires Filing of this Statement) Check the appropriate bo

Joint Filing Agreement

EX-99.1 2 opalex9901.htm JOINT FILING AGREEMENT Exhibit 99.1 JOINT FILING AGREEMENT Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (the “Exchange Act”) the undersigned hereby agree to the joint filing on behalf of each of them of any filing required by such party under Section 13 of the Exchange Act or any rule or regula

US68347P1030 / OPAL Fuels, Inc. / Encompass Capital Advisors LLC Passive Investment

SC 13G/A 1 encompass-opal123122a1.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Opal Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001 per share (Title of Class of Securities) 68347P103 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Che

US68347P1030 / OPAL Fuels, Inc. / CITADEL ADVISORS LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm233474-17sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2 (Amendment No. 1)* OPAL FUELS INC. (Name of Issuer) Class A Common Stock, par value $0.0001 per share (the “Shares”)

US68347P1030 / OPAL Fuels, Inc. / Beryl Capital Management LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001 (Title of Class of Securities) 68347P103 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pur

US68347P1030 / OPAL Fuels, Inc. / ADAGE CAPITAL PARTNERS GP, L.L.C. - OPAL FUELS, INC. Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* OPAL Fuels Inc. (f/k/a ArcLight Clean Transition Corp. II) (Name of Issuer) Class A Common Stock, par value $0.0001 per share (Title of Class of Securities) 68347P103 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of This Statement) Check the

US68347P1030 / OPAL Fuels, Inc. / Zimmer Partners, LP Passive Investment

SC 13G 1 formsc13g-opal.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) (Amendment No. ) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2 UNDER THE SECURITIES EXCHANGE ACT OF 1934 OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $0.0001 per

US68347P1030 / OPAL Fuels, Inc. / ArcLight CTC Holdings II, L.P. - AMENDMENT NO. 2 TO SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 2)* OPAL FUELS INC. (Name of Issuer) Class A common stock, par value $0.0001 per share (Title of Class of Securities) 68347P 103 (CUSIP Number) Christine M. Miller c/o ArcLight CTC Holdings II, L.P. 200 Clarendon St, 55th Floor Boston, MA 02116 (617) 531-630

US68347P1030 / OPAL Fuels, Inc. / BARCLAYS PLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* OPAL Fuels Inc. (Name of Issuer) Class A Common Stock, par value $.0001 per share (Title of Class of Securities) 68347P103 (CUSIP Number) 31-Dec-22 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pur

US68347P1030 / OPAL Fuels, Inc. / ArcLight CTC Holdings II, L.P. - AMENDMENT NO. 1 TO SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D UNDER THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No. 1)* OPAL FUELS INC. (Name of Issuer) Class A common stock, par value $0.0001 per share (Title of Class of Securities) 68347P 103 (CUSIP Number) Christine M. Miller c/o ArcLight CTC Holdings II, L.P. 200 Clarendon St, 55th Floor Boston, MA 02116 (617) 531-630

OPAL Fuels Inc. Announces Successful Completion of Exchange Offer and Consent Solicitation Relating to Warrants

FOR IMMEDIATE RELEASE OPAL Fuels Inc. Announces Successful Completion of Exchange Offer and Consent Solicitation Relating to Warrants WHITE PLAINS, N.Y. ? (December 22, 2022) ? OPAL Fuels Inc. (?OPAL Fuels? or the ?Company?) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas, today announced the completion of its previously disclosed exchange offer (t

OPAL FUELS INC.

Prospectus Supplement No. 6 Filed pursuant to Rule 424(b)(3) (To Prospectus dated November 8, 2022) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated November 8, 2022 (the ?Prospectus?), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospe

OPAL FUELS INC.

Prospectus Supplement No. 5 Filed pursuant to Rule 424(b)(3) (To Prospectus dated November 8, 2022) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated November 8, 2022 (the ?Prospectus?), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospe

Financial Statements and Exhibits, Other Events

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): December 22, 2022 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-

Service Contract Agreement , dated December 15, 2022, by and between OPAL Fuels Inc. and United Parcel Service Oasis Supply Corporation

[*] Certain information in this document has been omitted from this exhibit because it is both (i) not material and (ii) would be competitively harmful if publicly disclosed.

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): December 15, 2022 OPAL Fuels Inc.

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): December 15, 2022 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-

FM3 Credit Agreement, dated December 19, 2022, by and between Fortistar Methane LLC, OPAL Fuels LLC and a syndicate of lenders led by MUFG Union Bank N.A. as administrative agent (incorporated by reference to Exhibit 10.2 to the Current Report on Form 8-K filed by the Company on December 21, 2022).

Execution Version OMNIBUS AMENDMENT AND CONSENT AGREEMENT This OMNIBUS AMENDMENT AND CONSENT AGREEMENT, dated as of December 19, 2022 (this “Amendment”), is entered into by and among FORTISTAR METHANE 3 LLC, a Delaware limited liability company (the “Borrower”), each of the Lenders party hereto (the “Lenders”), MUFG BANK, LTD.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 (AMENDMENT NO. 1) OPAL FUELS INC. (Name of Subject Company and Filing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 (AMENDMENT NO. 1) OPAL FUELS INC. (Name of Subject Company and Filing Person (Issuer)) Warrants to Acquire Shares of Class A Common Stock 68347P 111 (Title of Class of Securities) (CUSIP Number of Class of Securities) A

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): December 16, 2022 OPAL Fuels Inc.

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): December 16, 2022 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-

Amendment No. 1 to Warrant Agreement, dated December 19, 2022, by and between OPAL Fuels Inc. and Continental Stock Transfer & Trust Company

Execution Version AMENDMENT NO. 1 TO WARRANT AGREEMENT This amendment (this ?Amendment?) is made as of December 19, 2022, by and between OPAL Fuels Inc., a Delaware corporation (the ?Company?), and Continental Stock Transfer & Trust Company, a New York corporation, as warrant agent (the ?Warrant Agent?), and constitutes an amendment to that certain Warrant Agreement, dated as of March 25, 2021 (th

OPAL Fuels Inc. Announces Successful Warrant Exchange Offer

FOR IMMEDIATE RELEASE OPAL Fuels Inc. Announces Successful Warrant Exchange Offer WHITE PLAINS, N.Y. ? (December 19, 2022) ? OPAL Fuels Inc. (?OPAL Fuels? or the ?Company?) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas, today announced the expiration and results of its previously disclosed exchange offer (the ?Offer?) and consent solicitation (th

Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

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): December 16, 2022 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-

OPAL FUELS INC.

Prospectus Supplement No. 4 Filed pursuant to Rule 424(b)(3) (To Prospectus dated November 8, 2022) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated November 8, 2022 (the ?Prospectus?), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospe

OPAL Fuels Inc. Announces Successful Warrant Exchange Offer

FOR IMMEDIATE RELEASE OPAL Fuels Inc. Announces Successful Warrant Exchange Offer WHITE PLAINS, N.Y. ? (December 19, 2022) ? OPAL Fuels Inc. (?OPAL Fuels? or the ?Company?) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas, today announced the expiration and results of its previously disclosed exchange offer (the ?Offer?) and consent solicitation (th

Amendment No. 1 to Warrant Agreement, dated December 19, 2022, by and between OPAL Fuels Inc. and Continental Stock Transfer & Trust Company

Execution Version AMENDMENT NO. 1 TO WARRANT AGREEMENT This amendment (this ?Amendment?) is made as of December 19, 2022, by and between OPAL Fuels Inc., a Delaware corporation (the ?Company?), and Continental Stock Transfer & Trust Company, a New York corporation, as warrant agent (the ?Warrant Agent?), and constitutes an amendment to that certain Warrant Agreement, dated as of March 25, 2021 (th

PROSPECTUS/OFFER TO EXCHANGE OPAL FUELS INC. Offer to Exchange Warrants to Acquire Shares of Class A Common Stock of OPAL Fuels Inc. for Shares of Class A Common Stock of OPAL Fuels Inc. and Consent Solicitation

424B3 1 ea170183-424b3opalfuel.htm PROSPECTUS SUPPLEMENT Filed pursuant to Rule 424(b)(3) Registration No. 333-268455 PROSPECTUS/OFFER TO EXCHANGE OPAL FUELS INC. Offer to Exchange Warrants to Acquire Shares of Class A Common Stock of OPAL Fuels Inc. for Shares of Class A Common Stock of OPAL Fuels Inc. and Consent Solicitation THE OFFER PERIOD (AS DEFINED BELOW) AND WITHDRAWAL RIGHTS WILL EXPIRE

Report of Independent Registered Public Accounting Firm

Report of Independent Registered Public Accounting Firm Shareholders and Board of Directors OPAL Fuels Inc.

OPAL FUELS INC.

Prospectus Supplement No. 3 Filed pursuant to Rule 424(b)(3) (To Prospectus dated November 8, 2022) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated November 8, 2022 (the ?Prospectus?), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospe

Financial Statements and Exhibits, Other Events

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 22, 2022 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-

Tender and Support Agreement, dated as of November 18, 2022, by and among OPAL Fuels Inc. and the public warrant holders and private warrant holders party thereto (incorporated by reference to Exhibit 10.22 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 10.22 TENDER AND SUPPORT AGREEMENT This TENDER AND SUPPORT AGREEMENT (this ?Agreement?), dated as of November 18, 2022, is entered into by and among OPAL Fuels Inc., a Delaware corporation (the ?Company?), each of the persons listed on Schedule A hereto (each, a ?Public Warrant Holder?) and each of the persons listed on Schedule B hereto (each, a ?Private Warrant Holder? and, together with

Form of Notice of Guaranteed Delivery (incorporated by reference to Exhibit 99.2 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 99.2 NOTICE OF GUARANTEED DELIVERY OF WARRANTS OF OPAL FUELS INC. Pursuant to the Prospectus/Offer to Exchange, dated November 18, 2022 Instructions for Use Unless defined herein, terms used in this notice of guaranteed delivery (this ?Notice of Guaranteed Delivery?) shall have the definitions set forth in the prospectus/offer to exchange, dated November 18, 2022 (as amended or supplemente

OPAL FUELS INC.

Prospectus Supplement No. 2 Filed pursuant to Rule 424(b)(3) (To Prospectus dated November 8, 2022) Registration Statement No. 333-266757 OPAL FUELS INC. This prospectus supplement updates, amends and supplements the prospectus dated November 8, 2022 (the ?Prospectus?), which forms a part of our Registration Statement on Form S-1 (Registration No. 333-266757). Capitalized terms used in this prospe

OPAL Fuels Inc. Announces Commencement of Exchange Offer and Consent Solicitation Relating to Warrants

FOR IMMEDIATE RELEASE OPAL Fuels Inc. Announces Commencement of Exchange Offer and Consent Solicitation Relating to Warrants WHITE PLAINS, N.Y. ? (November 18, 2022) ? OPAL Fuels Inc. (?OPAL Fuels? or the ?Company?) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas, today announced that it has commenced an exchange offer (the ?Offer?) and consent sol

As filed with the U.S. Securities and Exchange Commission on November 18, 2022.

As filed with the U.S. Securities and Exchange Commission on November 18, 2022. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549 FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 OPAL FUELS INC. (Exact name of registrant as specified in its charter) Delaware 4932 98-1578357 (State or other jurisdiction of incorporation or organization) (Pr

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 18, 2022 OPAL Fuels Inc.

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 18, 2022 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-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 OPAL FUELS INC. (Name of Subject Company and Filing Person (Issuer))

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 OPAL FUELS INC. (Name of Subject Company and Filing Person (Issuer)) Warrants to Acquire Shares of Class A Common Stock 68347P 111 (Title of Class of Securities) (CUSIP Number of Class of Securities) Ann Anthony Chief F

Form of Letter of Transmittal and Consent (incorporated by reference to Exhibit 99.1 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 99.1 LETTER OF TRANSMITTAL AND CONSENT Offer to Exchange Warrants to Acquire Shares of Class A Common Stock of OPAL Fuels Inc. for Shares of Class A Common Stock of OPAL Fuels Inc. and Consent Solicitation THE OFFER AND CONSENT SOLICITATION (AS DEFINED BELOW) AND WITHDRAWAL RIGHTS WILL EXPIRE AT 11:59 P.M., EASTERN TIME, ON DECEMBER 16, 2022, OR SUCH LATER TIME AND DATE TO WHICH WE MAY EXT

Financial Statements and Exhibits, Other Events

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 18, 2022 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-

Form of Letter to Clients of Brokers, Dealers, Commercial Banks, Trust Companies, and Other Nominees (incorporated by reference to Exhibit 99.4 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 99.4 LETTER TO CLIENTS OF BROKERS, DEALERS, COMMERCIAL BANKS, TRUST COMPANIES, AND OTHER NOMINEES Offer to Exchange Warrants to Acquire Shares of Class A Common Stock of OPAL Fuels Inc. for Shares of Class A Common Stock of OPAL Fuels Inc. and Consent Solicitation THE OFFER AND CONSENT SOLICITATION (EACH AS DEFINED BELOW) AND WITHDRAWAL RIGHTS WILL EXPIRE AT 11:59 P.M., EASTERN TIME, ON DE

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Table Form S-4 (Form Type) OPAL FUELS INC. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration F

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Table SC TO-I (Form Type) OPAL FUELS INC. (Exact Name of Registrant as Specified in its Charter) Table 1: Transaction Valuation Transaction Valuation(1) Fee Rate Amount of Filing Fee(2) Fees to be paid $ 19,540,588 $ 0.00011020 $ 2,154 Fees previously paid ? ? Total Transaction Valuation $ 19,540,588 Total Fees Due for Filing $ 2,154 Total Fee Offsets ? Net Fe

Form of Letter to Brokers, Dealers, Commercial Banks, Trust Companies, and Other Nominees (incorporated by reference to Exhibit 99.3 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 99.3 LETTER TO BROKERS, DEALERS, COMMERCIAL BANKS, TRUST COMPANIES, AND OTHER NOMINEES Offer to Exchange Warrants to Acquire Shares of Class A Common Stock of OPAL Fuels Inc. for Shares of Class A Common Stock of OPAL Fuels Inc. and Consent Solicitation THE OFFER AND CONSENT SOLICITATION (EACH AS DEFINED BELOW) AND WITHDRAWAL RIGHTS WILL EXPIRE AT 11:59 P.M., EASTERN TIME, ON DECEMBER 16,

OPAL Fuels Inc. Announces Commencement of Exchange Offer and Consent Solicitation Relating to Warrants

FOR IMMEDIATE RELEASE OPAL Fuels Inc. Announces Commencement of Exchange Offer and Consent Solicitation Relating to Warrants WHITE PLAINS, N.Y. ? (November 18, 2022) ? OPAL Fuels Inc. (?OPAL Fuels? or the ?Company?) (Nasdaq: OPAL), a leading vertically integrated producer and distributor of renewable natural gas, today announced that it has commenced an exchange offer (the ?Offer?) and consent sol

Dealer Manager Agreement, dated as of November 18, 2022, by and between OPAL Fuels Inc. and BofA Securities, Inc., as dealer manager (incorporated by reference to Exhibit 10.21 to the Company’s Registration Statement on Form S-4, filed with the SEC on November 18, 2022).

Exhibit 10.21 Execution Version OPAL Fuels Inc. Dealer Manager and Solicitation Agent Agreement New York, New York November 18, 2022 BofA Securities, Inc., as Dealer Manager c/o BofA Securities, Inc. One Bryant Park New York, New York 10036 Ladies and Gentlemen: OPAL Fuels Inc., a Delaware corporation (the ?Company? or ?we?), plans to make an offer (such offer as described in the Prospectus (as de

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) 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 14,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) 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 14, 2022 OPAL Fuels Inc. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation) 001-40272 (Commiss