Nevada Power Company, a wholly-owned subsidiary of Sierra Pacific Resources (NYSE:SRP), announced today that it has issued a request for proposals for energy supply, including firm energy and various tolling and other power products. The deadline to submit a proposal is on or before 9 a.m. Pacific time on Thursday, August 9, 2007.

Nevada Power will accept proposals for five to 10 year terms beginning in 2008, 2009, 2010 and 2011. The minimum acceptable bid will be for 25 MW. The complete request for proposals (RFP) can be found on the company's website athttp://www.nevadapower.com/company/RFPs/.

All proposals must comply with the requirements and guidelines set forth in the RFP.

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 800,000 residential and business customers in a 4,500 square mile service area.

Headquartered in Nevada, Sierra Pacific Resources is a holding company whose principal subsidiaries are Nevada Power Company, the electric utility for most of southern Nevada, and Sierra Pacific Power Company, the electric utility for most of northern Nevada and the Lake Tahoe area of California. Sierra Pacific Power Company also distributes natural gas in the Reno-Sparks area of northern Nevada.