Sierra Pacific Power Company, a subsidiary of Sierra Pacific Resources (NYSE: SRP), filed today with the Public Utilities Commission of Nevada (PUCN) to update its rates in the face of escalating energy prices to reflect increasing costs for fuel and power purchased to serve its customers. The filings include an update of electric rates for northern Nevada customers, and a rate update for natural gas customers in the Reno-Sparks metropolitan area.

If approved, the company's filing related to its electricity customers in northern Nevada calls for a $32.3 million increase in rates, which for the typical residential customer using 715 kilowatt hours of electricity, would mean a 3.2 percent increase, or a rise of approximately $2.80 per month. For natural gas customers, the $29 million increase that was filed means that the typical natural gas customer using 59 therms of natural gas would see an 18.9 percent increase, or approximately $12 per month.

"The primary driver for the proposed increases is the high price of natural gas, which is used in both producing electricity as well as supplying our Reno-Sparks gas customers," said Mary Simmons, Vice President, External Affairs, for Sierra Pacific Power. "Natural gas prices throughout the United States have been at record high levels. While our overriding goal is keep prices as stable as possible for our customers, the unprecedented high prices for natural gas require us to request this increase. These filings do not include any profit for the company, but only reflect the forecast price our company expects to pay suppliers for fuel and power to supply customers.

For Reno-Sparks natural gas customers, the energy price update is part of an annual mandatory filing with the PUCN that Sierra Pacific made in May. At the time of the filing, the company requested to delay its update of energy prices because of the volatility of forecasted natural gas prices for the winter of 2005-06. In its annual mandatory filing last May, the company requested to recover an under collection of $6 million the company spent from April 2004 to March 2005 to provide natural gas to customers. That request would add approximately $2 per month to residential customers' bills.

The company noted that natural gas prices throughout the United States over the past year have reached their highest levels in history. Natural gas prices have tripled since the 1990s, according to a survey from the Energy Information Administration, a division of the U.S. Department of Energy.

Sierra Pacific is required by the PUCN to update its energy rates annually, but may file mid-year if prices fluctuate significantly. The purpose of this mid-year filing is an attempt to prevent or reduce the build-up of a large under collection that customers would be asked to pay at a later time.

Following a thorough review by the PUCN, new electric rates are expected to become effective Oct. 1, 2005, with new natural gas rates effective Nov. 1, 2005.

Conservation Tips

Sierra Pacific also noted that natural gas usage among customers is typically low in the summer months, but it's not too early to begin preparing for next winter's heating season. "There are a number of things we can all do to improve the energy efficiency of our homes and businesses that will reduce bills and save money," Simmons said.

A description of energy efficiency tips, programs, even a home energy audit are available on Sierra Pacific's website at: http://www.sierrapacific.com/conservation/residential/tips/. The company also has brochures that urge customers to "Take Control of Your Energy Use," available at the company's office, or by calling 775-834-4444.

Sierra Pacific Power Company serves approximately 300,000 electric customers in Nevada and 135,000 natural gas customers in the Reno-Sparks metropolitan area. Sierra Pacific Power Company is a wholly-owned subsidiary of Sierra Pacific Resources (NYSE: SRP).

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: Statements in this press release regarding Sierra Pacific Resources' business which are not historical facts are "forward-looking statements" that involve risks and uncertainties. For a discussion of such risks and uncertainties, which could cause actual results to differ from those contained in the forward-looking statements, see "Risk Factors" in the Company's Annual Report on Form 10-K for the most recently ended fiscal year.

  A list of money-saving energy conservation tips follows.

                     Take Control of your Energy Use

  Money Saving Conservation Tips for Electric and Natural Gas Customers

       http://www.sierrapacific.com/conservation/residential/tips/

   No-Cost Tips
   Save 10 to 25 percent on your energy bill
     *  Turn off lights and appliances when not in use.
     *  In the winter, turn your thermostat down when sleeping or not at
        home.
     *  In the summer, turn your thermostat up when sleeping or not at home.
     *  Set your water heater thermostat to 120 degrees.
     *  Vacuum the coils underneath and on back of your refrigerator.
     *  Close foundation vents in the winter months.

   Low-Cost Tips
   Save an additional 10 to 25 percent
     *  Change incandescent bulbs to compact fluorescent bulbs.  You can
        typically save one dollar per month on each bulb changed
        (For bulbs on four to six hours per day.)
     *  Caulk windows and weather-strip doors.
     *  Install a water heater blanket.  Install water pipe insulation.
     *  Plant trees and shrubs on south and west sides of residence.
     *  Fix leaky faucets.  Install low-flow showerheads.
     *  Use ceiling or room fans to keep the air moving.
     *  Replace furnace and air conditioner filters monthly.

   Added-Cost Tips
   Save up to an additional 25 percent
     *  Fully insulate your attic, walls, pipes and air ducts.
     *  Upgrade your windows to vinyl frame, double-pane units.
     *  Replace your old appliances with new energy-efficient models.

SOURCE: Sierra Pacific Power Company

CONTACT: Media, Faye I. Andersen, +1-775-834-4822, or Analysts, Britta
Carlson, +1-702-367-5624, both for Sierra Pacific Power Company

Web site: http://www.sierrapacific.com/conservation/residential/tips

Web site: http://www.sierrapacific.com/