With a moderate price on carbon, the company would have a vast potential market--it could profitably sell its technology to capture 18 percent to 25 percent of carbon-dioxide emissions worldwide, the company says. Joe Jones, Skyonic's CEO, says that a price on carbon "is not critical for us now." Eventually, the company could find it difficult to grow, which would mean it would need a price on carbon "sometime in the next five to 10 years," Jones said.

Solar and wind companies are in the best situation. They enjoy many government subsidies, such as tax credits for new installations, and in some markets can compete with power from conventional sources. In contrast, advanced biofuels companies that could offset emissions from petroleum by making fuel from sources such as grass and agricultural waste aren't doing well--no commercial advanced biorefineries have been built yet.

But leaders in the biofuels industry are hoping less for a price on carbon--although that would help--than for loan guarantees that could help get the first plants built. Many advanced biofuels companies say that once they can get financing to build their plants, the technology can be profitable without a price on carbon.

Indeed, many venture capitalists have refused to invest in companies that depend on a carbon price. "We've never seen that it's viable to build a company whose entire financial success is based around the existence of a carbon tax or cap-and-trade system--especially before you know what it's going to look like," says David Berry, a partner at Flagship Ventures.

Although Congress hasn't passed a comprehensive climate bill, other government entities are stepping in, and that could give hope to companies that reduce carbon emissions. Victor points to a new law in Colorado that directs the state's utilities commission to regulate power companies "as if carbon were being regulated at the federal level," he says.

Meanwhile, new U.S. Environmental Protection Agency regulations of power plant emissions may force some coal plants to shut down, opening the way to renewable energy. And even if the United States does nothing, Berry says, some companies can look to overseas markets, such as Europe, where there are controls on carbon dioxide. "A lot of interesting American technologies might start to get sent overseas," he says.