Catalytica Energy Systems Announces Record Date for Special Meeting to Vote on Merger Proposal

Catalytica Energy Systems, Inc. (NASDAQ: CESI) announced today that stockholders of record of the Company as of the close of business on Friday, August 31, 2007 will be entitled to receive notice of and to vote at a forthcoming Special Meeting of Stockholders. The purpose of the Special Meeting will be to consider and vote on the proposed merger agreement between Catalytica Energy Systems and the renewable energy divisions of NZ Legacy, LLC, pursuant to which the companies will combine and operate under a new holding company to be named Renegy Holdings, Inc.

Catalytica Energy Systems anticipates mailing proxy materials relating to the merger transaction for stockholder consideration as soon as practicable following the record date once the definitive registration statement on Form S-4 is filed with and declared effective by the Securities and Exchange Commission (SEC). The definitive proxy statement / prospectus that will be mailed to stockholders will contain the date, time and location of the Special Meeting. The transaction, which has been unanimously approved by the Board of Directors of Catalytica Energy Systems, is subject to approval by the stockholders of Catalytica Energy Systems, regulatory approvals and customary closing conditions, and is expected to close by the end of the third quarter of 2007.

Catalytica Energy Systems, based in Tempe, Arizona, provides innovative products and services to meet the growing demand for clean energy production, with a focus on cost-effective emissions control solutions for the coal-fired power generation industry. Through its SCR-Tech subsidiary (www.SCR-Tech.com), the Company offers a variety of services for coal-fired power plants that use selective catalytic reduction (SCR) systems to reduce nitrogen oxides (NOx) emissions. These services include SCR catalyst management, cleaning and regeneration, as well as consulting services to help power plant operators optimize efficiency and reduce overall NOx compliance costs. Find Catalytica Energy Systems on the Worldwide Web at www.CatalyticaEnergy.com.

Additional Information and Where to Find It

This document does not constitute an offer of any securities for sale. The proposed merger transaction described herein will be submitted to the stockholders of Catalytica Energy Systems, Inc. for their consideration. In connection with the proposed merger, Renegy Holdings, Inc. has filed a registration statement, a proxy statement / prospectus and other materials with the SEC. CATALYTICA ENERGY SYSTEMS URGES INVESTORS TO READ THE REGISTRATION STATEMENT AND THE PROXY STATEMENT / PROSPECTUS AND THESE OTHER MATERIALS CAREFULLY BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT CATALYTICA ENERGY SYSTEMS, SNOWFLAKE WHITE MOUNTAIN POWER, RENEGY, RENEGY TRUCKING, AND THE PROPOSED TRANSACTION. Investors also may obtain information about the proposed transaction by reviewing the Form 8-K filed by Catalytica Energy Systems on May 8, 2007 in connection with the announcement of the transaction and any other documents filed with the SEC when they become available. Investors may obtain free copies of the proxy statement / prospectus as well as other filed documents containing information about Catalytica Energy Systems at http://www.sec.gov, the SEC's public website. These SEC filings may also be obtained free of charge on Catalytica Energy Systems' Web site at http://www.CatalyticaEnergy.com or by calling the Company's investor relations department at (650) 631-2847.

Participants in the Solicitation

Catalytica Energy Systems and its executive officers and directors may be deemed, under SEC rules, to be participants in the solicitation of proxies from stockholders of Catalytica Energy Systems with respect to the proposed merger. Information regarding the officers and directors of Catalytica Energy Systems is included in Amendment No. 1 to the Company's Annual Report on Form 10-KSB for the fiscal year ended December 31, 2006, filed with the SEC on April 30, 2007. More detailed information regarding the identity of potential participants, and their direct or indirect interests, by securities holdings or otherwise, is set forth in the proxy statement / prospectus and other materials filed with the SEC in connection with the proposed merger.

This news release contains forward-looking statements within the meaning of the Securities Act of 1933, as amended, and the Securities Exchange Act of 1934, as amended, and is subject to the safe harbors created therein. These statements include, but are not limited to, those regarding the prospects and timing associated with consummation of the proposed merger; the anticipated mailing date of the proxy statement / prospectus. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those expressed in the forward-looking statements. These risks and uncertainties include, among others, the risk that we will not be able to close the transaction, diversion of management's attention away from other business concerns and the other risks set forth in the Company's most recent Form 10-KSB and subsequent Forms 10-QSB and the Registration Statement on Form S-4 relating to the Transaction, filed with the Securities and Exchange Commission. Further, the Company expects to incur substantial transaction and merger related costs associated with completing the merger and combining the operations of the two companies. Expected benefits of the merger may not be achieved in the near term, or at all. The combined company will have a significant amount of debt as a result of the merger. This debt will require us to use cash flow to repay indebtedness, may have a material adverse effect on our financial health, and may limit our future operations and ability to borrow additional funds, including funds for new projects. In addition, a trust controlled by Bob Worsley will own a controlling interest in the Company and will be able to exert significant influence over the business of the Company. The Company undertakes no obligation to update any forward-looking statements to reflect new information, events, or circumstances occurring after the date of this release.