On October 28, 2022, William J. Clinton resigned from the board of directors of TortoiseEcofin Acquisition Corp. III and all committees thereof. Mr. Clinton's resignation was not a result of any disagreement with the company on any matters related to the company's operation, policies or practices.

In connection with Mr. Clinton's resignation and in accordance with the terms of the arrangement to which all independent directors agreed at the time of their appointment to the Board, Mr. Clinton forfeited to the Company all of the Class B ordinary shares, par value $0.0001 per share (the “Class B Ordinary Shares”), which were previously issued to him in connection with his appointment to the Board. On October 31, 2022, Greg A. Walker was appointed as a member of the Board to fill the vacancy on the Board resulting from Mr. Clinton's resignation. The Board has determined that Mr. Walker is an “independent director” as defined in the New York Stock Exchange (NYSE) listing standards and applicable U.S. Securities and Exchange Commission (the SEC) rules and regulations.

Mr. Walker will serve on the audit, compensation and nominating and corporate governance committees and serve as chair of the nominating and corporate governance committee. From 2011 to 2018, Mr. Walker was a member of the Board of Directors of Armstrong Energy Inc., which operated mining, processing and loading facilities in the Illinois Basin, where he also served as the Chairman of the Conflicts Committee and a member of the Audit and Compensation Committees. From July 2009 through January 2011, Mr. Walker served as a Senior Vice President of Alpha Natural Resources Inc., a publicly traded mining company, where he assisted with integration issues after the 2009 merger of Alpha Natural Resources Inc. and Foundation Coal Holdings Inc. From 2004 through July 2009, Mr. Walker served as the Senior Vice President, General Counsel and Secretary of Foundation Holdings, which was acquired in 2004 by a consortium of Blackstone Group, L.P., First Reserve Corporation and American Metals & Coal International Inc. At Foundation Holdings, Mr. Walker oversaw all legal and regulatory matters related to the formation, financing, registration and initial public offering of the company on the NYSE.

In his position as General Counsel of Foundation Holdings, he also had management oversight for the legal, environmental, land and government affairs functions at the company and had operational responsibility for the natural gas and coalbed methane business, which was developed into a successful operating asset under his leadership. From 1999 to 2004, Mr. Walker served as the Senior Vice President, General Counsel and Secretary of RAG American Coal Holdings Inc., which was the predecessor entity to Foundation Holdings. From 1989 through 1999, Mr. Walker served in various capacities in the law department of Cyprus Amax Minerals Company, which was one of the largest integrated mining companies in the United States.

From 1986 to 1989, Mr. Walker was a litigation and regulatory attorney for a private law firm. From 1981 through 1986, he held various positions within the law department of Mobil Oil Corporation in New York, New York and Denver, Colorado. Mr. Walker was also a member of the Board of Directors of FutureGen Industrial Alliance Inc. (“FutureGen”) from 2005 through 2011, and in 2008, he served as the Chairman of the Board of Directors of FutureGen, which was a not-for-profit international alliance of major utilities and mining companies whose members worked with the United States Department of Energy to develop plans to design, build and operate a commercial scale power plant and associated carbon dioxide capture and sequestration project.

Mr. Walker received a Bachelor of Arts degree from the University of Pennsylvania, where he graduated cum laude with distinction with a double major in Geology and Environmental Sciences, and a Juris Doctor degree from the University of Florida, College of Law, where he received various awards.