The plan of three solar technology experts is outlined in the January issue of Scientific American. They propose covering thousands of square miles in the southwestern U.S. with photovoltaic arrays that convert sunlight into electricity, using direct current to ship electricity hundreds of miles to population centers.

Some electricity created during the day would be used to pump compressed air into underground caverns for nighttime use in driving generators.

Ken Zweibel, James Mason and Vasilis Fthenakis say their practical plan will help cut air pollution and reverse the climate change trend.

The Solar Grand Plan would cost an estimated $420 billion in government subsidies spread out over many years. The authors propose to pay for it with a modest tax on carbon released by the burning of conventional fuels.

They assume energy demand will grow 1 percent annually and by 2050 solar power will supply 69 percent of U.S. electricity and 35 percent of all U.S. energy.

It also incorporates plug-in hybrid cars, new domestic jobs in manufacturing solar components and all of the environmental benefit.

"Americans know our country has energy problems," Zweibel said. "We have a lot of coal, some natural gas and dwindling domestic oil. The number of energy choices is getting smaller. What we're saying is that solar is a major choice and it's now ready. It's a big deal that should seriously be considered. It's no longer a boutique solution."