"We look at (the renewable law) as a floor, rather than a ceiling," said Bill Heck, the company's manager of renewable energy.

The utilities will consider contracting for renewable energy to be delivered before it needs the green power to satisfy the state law, he said.

The company will also consider proposals to build renewable-power plants that the utilities could purchase and proposals to buy renewable energy from plants owned by others, Heck said.

Sierra Pacific Resources will choose projects based on three priorities: the price of the renewable power, technical aspects of the project and the commercial aspects of the bidder, including whether the bidder has the financial strength to build the project.

The utilities will need additional solar power by 2013. The renewable-energy law requires that 5 percent of the renewable sources must come from solar energy projects.

"We are especially looking for wind power resources," because no wind power projects have been built in Nevada yet, Heck said. The utility company is collecting wind data at several locations, rather than relying on wind power developers to study wind data. Eastern Nevada has some of the state's windiest conditions, but other areas could be used for wind farms, Heck said.

The companies are interested in various kinds of renewable-energy projects, including biomass and waste heat recovery from an industrial process.

The utilities have three geothermal power contracts awaiting Public Utilities Commission approval. They are the 62-megawatt Carson Lake Basin project near Fallon, 31-megawatt ORNI 20 project near Lander County, and the 46-megawatt TG Power plant near Elko.

Geothermal units use hot underground water or steam to generate electricity.

"The geothermal industry is well-developed in Nevada," Heck said, and many projects have been built in areas with known geothermal resources.

Responses to the request are due at the company on Nov. 13. The company expects to prepare a short list of the most attractive proposals by January and to seek commission approval for some of the projects in summer 2008.

Separately, the utility holding company on Monday announced it was forming the Nevada Geothermal Energy Technical Advisory Panel to advise senior managers on geothermal power.

"Forming this panel is a critical step in insuring that the company receives the best advice possible for long term planning to fully realize benefits of Nevada's geothermal energy resources," Tom Fair, an executive for renewable energy at Sierra Pacific Resources.

David Blackwell, professor of geology at Southern Methodist University, will be chairman.

Other members are Leland "Roy" Mink, retired program director for geothermal technologies at the U.S. Department of Energy; Lisa Shevenell, an hydrogeologist for the Nevada Bureau of Mines and director of the Great Basin Center for Geothermal Energy; and Subir Sanyal, the president and manager of reservoir engineering services of GeothermEx.