The project could power thousands of homes and help utilities meet the state's renewable-energy requirements, the Tucson Citizen said.

Arizona Public Service Co., Salt River Project, Tucson Electric Power and several smaller companies are hoping to save some money by working together. The companies announced they are taking proposals from firms interested in building the project, which could be located in either Arizona or Nevada.

They are proposing a plant that can generate 250 megawatts -- enough to power 62,500 to 75,000 homes -- and reduce about 25 percent of the state's natural gas use.

The state has imposed a mandate that utilities get 15 percent of their electricity from renewable sources such as solar power by 2025 and the U.S. House of Representative passed a similar nationwide measure Thursday.

Utility representatives said they purchase some renewables, like wind and geothermal, but the state has great potential for producing solar power.