The Shrinking Cost for Solar Power

Until now solar power's biggest drawback has been that it costs more than electricity generated by conventional means. But many experts believe that, under certain circumstances, the premium for solar power can be erased, without subsidies or dramatic technical breakthroughs.

A sufficiently large solar thermal power plant (also called concentrated solar power, or CSP) could potentially generate electricity at about the same cost as electricity from a conventional gas-burning power plant, experts say.

"It's not easy. The plant would also have to come with a large energy storage system, be built next to others and be located close to users. To date, no one has completed a facility that comports to all of these parameters," said Fred Morse, an energy analyst who has studied the issue.

"Solar thermal is available at much more attractive prices than solar photovoltaic. The land mass isn't huge, but it does take a while to build these," said Stephan Dolezalek, a managing partner and co-head of the clean tech practice at venture firm Vantage Point Venture Partners, an investor in Bright Source Energy, which builds solar thermal plants and components.

Both Dolezalek and Jiang Lin, who heads up the China Energy Group at the Lawrence Berkeley National Laboratory, said that solar thermal is likely the most promising technology in the entire alternative-energy field right now.