However, Sempra's 10-megawatt, photovoltaic project in Boulder City's Eldorado Valley has been under construction since July and will start generating electricity this month. The power plant will be fully operational by the end of the year, Allman said. It is adjacent to Sempra Generation's gas-fired, 480-megawatt El Dorado Energy plant.

Sempra Generation is negotiating with two unidentified utilities with the expectation one will buy all of the plant's output, he said.

The solar plant will have the ability to generate enough power for 2,000 homes in Southern Nevada during peak periods of power use in the summer. So far, Nevada Power Co., which does business as NV Energy, obtains about 1 percent of its power from solar energy.

The new plant uses photovoltaic technology, which uses sunlight, rather than the heat from sunlight, to generate electricity. Conventional photovoltaic systems use crystalline silicon to make electricity, but Sempra uses thin-film technology, which is less efficient on a square footage basis but also less expensive than crystalline silicon.

The solar panels will occupy 88 acres, but Sempra has leased enough additional acreage from Boulder City to expand the plant's capacity to 60 megawatts.

Allman figures it's more important to use a less costly technology like thin-film photovoltaic panels than to minimize the footprint of the project.

"Whatever provides the lowest cost of electricity is what we're interested in," he said.

Thin-film solar costs less than even concentrating solar power projects, the technology that concentrates the heat of the sun to make water or another liquid boil and spin generators, he said.

An analyst who spoke on condition of anonymity said some factors, such as the type of thin-film technology being used, make it difficult to make sweeping generalizations about which technology will provide the least expensive energy.

While construction employment will peak at 75, Sempra will probably only need one worker to guard and do limited maintenance at the finished solar site, he said.

Allman expects the photovoltaic solar plant to last more than 30 years, although its generating output will degrade slowly over that period of time.

"We're interested in building a substantial renewable business," he said.

Sempra Generation set a goal of becoming the first company to build more than 500 megawatts of solar generation capacity in the United States, he said. Nevada "could be one of the leading solar (power) providers in the country," he said.

"It's a hot space," he said of solar energy. "I think people recognize this country needs to be weaned off its addiction to oil and fossil fuels."

Contact reporter John G. Edwards at jedwards@reviewjournal.com or 702-383-0420.