Facing a Congress that is more hostile to environmental regulation, President Barack Obama is moderating his environmental goals: a clean energy standard that mixes nuclear, natural gas and "clean coal" with renewable sources such as wind and solar.

In his State of the Union address Tuesday night, Obama called for 80 percent of the nation's electricity to come from clean sources by 2035. That goal represents a new strategy to reduce emissions of carbon dioxide blamed for global warming, following the death of cap-and-trade legislation that Obama pushed in Congress for the last two years. The president didn't mention global warming in his speech, but a clean energy standard is another way to combat rising temperatures.

The new target would double the percentage of electricity that comes from clean energy sources, according to a White House fact sheet. Clean coal, which would be produced by an experimental technology not yet available commercially, and "efficient natural gas" would be given only partial credits toward the goal.

Under the cap-and-trade system, government places a limit on pollution and allows companies to buy and sell pollution permits under that ceiling. Companies that can reduce their emissions cheaply can then sell their unused credits to those that cannot afford the costs of emission controls.

The clean energy standard represents a second fallback position to cap-and-trade. Last year, a powerful coalition of renewable energy producers, environmental groups, governors and even some utilities couldn't push a renewable electricity standard of 15 percent across the finish line, in part because of regional resistance. In the Southeast, for example, it was argued that the region lacks renewable sources like abundant levels of wind.

The nuclear industry soon touted the idea of a broader clean energy standard, which got a nod from Energy Secretary Steven Chu last month. Chu said a goal of 50 percent by 2050 would be "about right" — but it turned out to be much less than Obama is proposing. The energy secretary told reporters Wednesday that he had been responding to a suggested level.

"Now, since that time, we have gone back and looked at it and it depends on how you define it," Chu said after an online clean energy town hall. The U.S., he said, already gets about 40 percent of its electricity from clean energy sources and more than 30 percent from carbon-free sources.

Chu called the new proposal "a recognition that solutions can be different in different parts of the United States, but ... this is the goal we're looking for and depending on the region, you have different options of getting to that eventual goal."

The administration's plan has echoes of the GOP's "all of the above" approach to energy.

"Let's not pick just wind or solar, let's pick everything," White House spokesman Robert Gibbs told reporters Thursday. "Let's do all of it."

But whether the administration can win over many Republicans isn't clear yet. Rep. Doc Hastings, a Washington Republican who chairs the House Natural Resources Committee, said Obama "needs to embrace a robust plan to produce all types of American energy — from renewable to American-made oil and natural gas — and it has to be done without harmful government subsidies or unrealistic mandates."

Sen. Lamar Alexander, R-Tenn., a big proponent of nuclear power, said the policy was an improvement over a renewable energy standard, which he dismissed as "just a national windmill policy." But he said he didn't support a clean energy standard either.