A clean-room technician holds a black silicon solar-power wafer. Natcore Technology, Inc.

Solar power is one of those technologies that have been promised to be just a few years from profitability for 30 years. Solar panels are an environmentalist's dream - limitless electricity from the sun with no air pollution or carbon dioxide emissions - but they've had a hard time competing with coal, natural gas, oil and other sources of energy.

Can that change? A company called Natcore Technology says it may be on to something. It reports it has developed "absolute black" silicon wafers for solar panels that will absorb 99.7 percent of the visible light falling on them. The most efficient solar panels devised up to now have been able to absorb 96 percent. In a business where every photon counts, Natcore said the difference could be important.

"One of the ways this matters," said Chuck Provini, the company's CEO, "is that there isn't a whole lot of difference between the electricity you get on a sunny day vs. a cloudy day. Diffused light won't matter that much."

The new panels, Provini said, will not require hazardous chemicals to produce and should help drive down the price of solar energy.

"Black silicon will improve power output and reduce cost - the two things that matter most," he said.

"Solar has changed a lot in the last few years," said Monique Hanis of the Solar Energy Industries Association in an email. "As of 2011, there are 100,000 Americans working in solar [according to The Solar Foundation's 2011 Jobs Census] at 5,600 companies across all 50 states, including many small business. Solar installations doubled in 2011 and there are enough projects in the pipeline to power 2 million households."

The cost of solar power has kept edging downward at a time when the price of oil has been going up - something that makes it promising to its champions, but also makes it a political football. Last week, President Obama talked up the need for all sorts of new energy sources, from solar and wind energy to new pumping of oil and gas.

"You'd think that everybody would be supportive of solar power," Obama said at a solar plant in Nevada. "And yet, if some politicians had their way, there won't be any more public investment in solar energy. There won't be as many new jobs."

Those "some politicians," of course, include Obama's Republican challengers for the White House. Rick Santorum, campaigning among oil workers in Louisiana, pressed the president to open more federal land for oil drilling - a step, he argued, toward lower energy costs.

"Here's an opportunity for us in this country to do something about it: increasing jobs, lowering energy prices, decreasing the deficit, all of the things you would think he president of the United States would be for," Santorum said.

Solar power remains a small part of the nation's energy mix, but high oil prices give it new visibility.  Natcore hopes to be making solar panels from its new wafers in four to six weeks.

"People have been trying to get black silicon to work for years now," said Provini.