A number of existing power facilities burn grass, wood, or other kinds of biomass.
Regulation of existing power plants is further complicated by the pending nomination of Gina McCarthy to become E.P.A. administrator.
The government has identified eight sites suitable for new reactors, all at the sites of existing power plants.
Such devices could significantly increase the electrical output of existing power plants or power the electrical systems of automobiles, replacing alternators and increasing gas mileage.
He should instruct the Environmental Protection Agency to move ahead aggressively with regulation of existing power plants, which account for 40% of the country's greenhouse gas emissions.
Natural gas pipeline expansions, the repowering of existing power plants, energy conservation efforts and large alternative energy projects are also possibilities.
But supporters of the proposal say modernization has been held back because utilities have no guarantee that they can add to the more than 150,000 miles of existing power lines.
The so-called merchant sector of the industry, in which Duke Energy and other companies generate power to sell to other utilities, is growing rapidly through both acquisition of existing power plants and construction of new ones.
"Today's release of the EPA's draft regulation of existing power plants is an historic step in our nation's journey to overcome climate change," said Rev. Mitch Hescox, the group's president.
For the first time, limits will be imposed on the carbon dioxide output of existing power plants, which, as the biggest single source, account for 40% of America's carbon emissions.
The rules for new plants are far less costly and contentious than the rules the Environmental Protection Agency is now drawing up to regulate thousands of existing power plants, the ones producing all those emissions.
