The four largest utilities in New Mexico want to build the state's largest commercial solar power generating plant in move that could yield enough renewable energy to supply as many as 52,000 homes.

The proposal from El Paso Electric, Xcel Energy, PNM and Tri-State Generation and Transmission Association calls for the use of parabolic trough technology to deliver as much as 375,000 megawatt-hours annually.

If combined with thermal energy storage, the technology also could generate electricity when the sun isn't shining, such as at night or during cloudy weather.

The development comes within days of the Bureau of Land Management reversing itself on a moratorium on new solar power plants on public land announced last week for the Southwest region of the U.S.

The agency said at the time it wanted to study the environmental impact of the solar plants. The decision temporarily cast a cloud of uncertainty over the solar industry and 100-plus proposals filed during the last three years.

Utilities are increasingly trying to diversify their energy portfolios with renewables because of state mandates and potential climate change-related regulation. Pacific Gas and Electric Co. of Northern California, for example, signed a long-term agreement this week to buy 240 gigawatt hours of wind power from a Horizon Wind Energy subsidiary in Oregon beginning in 2009. Renewable energy must comprise at least 20 percent of the portfolios of California utilities by 2010.

The hot renewable energy market isn't confined to the U.S., according to a recent United Nations Report. The agency said Tuesday worldwide investment in renewable energy soared 60 percent to 148 billion in 2007, three times faster than expected.