Media Contact:  Sonya Headen
(702) 367-5222
Analyst Contact: Britta Carlson
(702) 367-5624

Las Vegas, Nev.-- Nevada Power Company, a subsidiary of Sierra Pacific Resources (NYSE:SRP), announced that the Public Utilities Commission of Nevada (PUCN) today unanimously approved the stipulation agreement filed on February 23, 2005, involving the company's annual deferred energy case.

As previously announced, the monthly bill of a typical residential customer using 1250 kilowatts will increase by 0.76 percent, or approximately 93 cents, from $122.33 to $123.26.  Overall rates, including commercial customers, will decrease by approximately 0.6 percent.  These rates also include recovery of costs associated with conservation and energy efficiency programs.

Under the agreement reached by Nevada Power, the staff of the PUCN, the State Attorney General's Bureau of Consumer Protection, and a coalition of major utility customers, Nevada Power will recover â€" on a dollar-for-dollar basis with no profit to the company -- $115.9 million in past fuel and purchased power costs.

The stipulation allows recovery of the past fuel and purchased power costs over the next two years with new rates effective on April 1, 2005.

Nevada Power Company is a regulated public utility engaged in the distribution, transmission, generation, purchase and sale of electric energy in the southern Nevada communities of Las Vegas, North Las Vegas, Henderson, Searchlight, Laughlin and their adjoining areas. The Company also provides electricity to Nellis Air Force Base, the Department of Energy at Mercury and Jackass Flats at the Nevada Test Site. Nevada Power Company provides electricity to approximately 725,000 residential and business customers in a 4,500 square mile service area.

This press release contains forward-looking statements regarding the future performance of Sierra Pacific Resources and its subsidiaries, Nevada Power Company and Sierra Pacific Power Company, within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are subject to a variety of risks and uncertainties that could cause actual results to differ materially from current expectations. For Sierra Pacific Resources, these risks and uncertainties include, but are not limited to, the Company's ability to maintain access to the capital markets, its ability to receive dividends from its subsidiaries and the financial performance of the Company's subsidiaries, particularly Nevada Power Company and Sierra Pacific Power Company. For Nevada Power Company and Sierra Pacific Power Company, these risks and uncertainties include, but are not limited to, adverse decisions in the Enron litigation or other pending or future litigation, unfavorable rulings in their pending and future rate cases, their ability to maintain access to the capital markets for general corporate purposes, their ability to purchase sufficient power to meet their power demands and weather conditions during the summer months of 2005 and beyond. Additional cautionary statements regarding other risk factors that could have an effect on the future performance of Sierra Pacific Resources, Nevada Power Company and Sierra Pacific Power Company are contained in the 2004 form 10K being filed with the SEC on March 16, 2005. The Companies undertake no obligation to release publicly the result of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.