Conference speakers at Solar Power 2007 saysolar-friendly policies are key to growing a stable, long-term market.

Ted Turner, best known for founding CNN, compared the situation for clean energy to the early days for the cable industry, when incumbents in network television "ganged up on" the new cable players.

"We've got a lot of work to do in Washington, no doubt about that," he said. "But almost everyone is aware of the problem now."

A number of speakers, including Turner, said the United States needs to level the playing field for green energy. While the price of solar power needs to drop to match the real costs of fossil fuels, those fuels' real costs aren't taken into account under the current prices, he said.

"We have to go at warp speed to use as little fossil fuels as we can," he said.

Ray Lane, a managing partner at Kleiner Perkins Caulfield & Byers, said he expects subsidies to drive solar down to carbon-based electricity prices - but "probably not with this administration."

"The question is not when solar will be competitive, but how long coal will be competitive with a level playing field."

He said Washington representatives should be embarrassed at how much states and cities have accomplished without the federal government "lifting a finger," but added that Washington will get involved if enough states adopt different rules.

"Policy is critical," he said. "We have to put a price on carbon. [Fossil fuels] can't compete for free."

Still, Rhone Resch, president of the Solar Energy Industries Association, said there is only a 50/50 chance for the U.S. energy bill to get passed. "That's why we are looking at next year," he said.

"We are building such support that we could override a veto," he added.

- Reporter Rachel Barron contributed to this story.