August 1, 2008

Dynegy Announces Completion of Sale of Rolling Hills Peaking Plant

Dynegy Inc. (NYSE:DYN) today announced that one of its subsidiaries has completed the sale of the Rolling Hills Power Generation Facility, a peaking plant located in Wilkesville, Ohio, to a company managed by Tenaska Capital Management, LLC for $368 million in cash. The sale equates to more than $450 per kilowatt based on the plant's summer capacity rating. Dynegy expects to record a gain on the sale of Rolling Hills of approximately $50 million, subject to adjustments for working capital and other items, in the third quarter 2008.

The Rolling Hills plant (815-megawatt summer capacity rating) is a natural gas-fired peaking facility that began commercial operation in 2003.

Through its subsidiaries, Dynegy Inc. produces and sells electric energy, capacity and ancillary services in key U.S. markets. The power generation portfolio consists of more than 18,000 megawatts of baseload, intermediate and peaking power plants fueled by a mix of natural gas, coal and fuel oil. DYNC

Certain statements included in this news release are intended as "forward-looking statements." These statements include assumptions, expectations, predictions, intentions or beliefs about future events, particularly the statements related to: the timing of this action or the recording of any gains. Dynegy cautions that actual future results may vary materially from those expressed or implied in any forward-looking statements. Specifically, Dynegy cautions that the transaction may not prove to be financially advantageous to Dynegy as a result of unknown market conditions, when the gains may actually be recorded and in what amounts. More information about the risks and uncertainties relating to these forward-looking statements are found in Dynegy's SEC filings, including its Annual Report on Form 10-K for the year ended December 31, 2007 and its quarterly report on Form 10-Q, as amended, for the quarter ended March 31, 2008, both of which are available free of charge on the SEC's web site at