President Carter told the American people last night that the alternative to accepting the energy policy that he will propose to Congress on Wednesday "may be a national catastrophe."

In a speech filled with rhetorical references to an impending energy doomaday, the President said that the nation is faced with "a problem unprecedented in our history" and that, with the exception of preventing war, dealing with the energy problem will be "the greatest challenge our country will face during our lifetime."

"If we fail to act soon, we will face an economic, social and political crisis that will threaten our free institutions," he warned.

The President said Wednesday's proposed alternative to an energy doomsday will include, by 1885, a cut in the growth rate of energy consumption by more than half, a slash in gasoline consumption and an increasing reliance on coal and solar energy.

Last night's occasion was bilied beforehand by a White House aide as "the sky is falling" speech, and in that sense Carter's remarks lived up to their advance billing. The President painted a grim portrait of the future should energy consumption continue unchecked - a future of rising inflation and unemployment, an era of "intense competition" among regions of the United States and among this and other nations seeking their share of dwindling world energy supplies.

Carter did not detail any of his proposed solutions, saving that for Wednesday night's address to a joint sesion of Congress.

Instead, the President last night attempted to lay the political and psychological groundwork for the energy proposals that will follow, warning that every segment of society will be asked to sacrifice in the cause of conservation but holding out hope that America's existing standard of living can be maintained.

"I can't tell you that these measures will be easy, nor will they be popular," he said. "But I think most of you realize that a policy which does not ask for changes or sacrifices would not be an effective policy.

"This plan is essential to protect our jobs, our environment, our standard of living and our future."

Clearly anticipating a long and brutal struggle to gain congressional approval of his energy plan, Carter also madw a direct appeal to the pupulace to resist efforts to dilute his proposals.

"We can be sure," he said, "that all the special interest groups in the country will attack the part of this plan that effects them directly. They will say that sacrifice is fine as long as other people do it, but that their sacrifice is unreasonable, or unfair, or harmful to the country.

"If they succeed, then the burden on the ordinary citizen, who is not organized into an interest group, would be crushing," he warned.

While the President made no specific proposals, he did set out seven goals of his energy program and 10 principles which he said guided its development.

He established 1985 as the target year for achieving the goals, the first of which is to slow the rate of growth in energy consumption from last year's 4.5 per cent to less than 3 per cent.

The other goals the President set in the energy message would:

Reduce gasoline comsumption, currently 7 million barrels a day, by 10 per cent.

Cut oil imports to 6 million barrels a day. Currently, the nation import 8 million barrels a day and Carter said this could grow to 16 million barrels a day.

Establish a strategic petroleum reserve of 1 billion barrels, enouth to last six months.

Increase coal production by about two thirds, to more than 1 billion tons a day.

Increase coal production by about two thirds, to more than 1 billion tons a day.

Insulate 90 per cent of American homes and all new buildings.

Extend solar energy, now in use in some 5,000 homes, to 2.5 million homes.

Detailing the principles that guided him, Carter said the "cornerstone" of his policy will be to reduce demand through conservation and the policy itself "must be fair."

"Our solutions must ask equal sacrifices from every region, every class of people, every region, group," he said.

"Industry will have to do its part to conserve, just as consumers will. The energy, just as consumers will. The energy producers deserve fair treatment, but we will not let the oil companies profiteer."

Other principles that the President set forth included commitments to protect the environment, to reduce vulnerability to foreign oil embargos, to conserve scare fuels such as oil while shifting to much higher coal consuption, and to begin developing now "new, unconventional" sources of energy for use in the 21st century.

But in speaking of principles, Carter also held out hope of a brighter day. The contrast with his grim warnings about sacrifice left the nature and extent of the sacrifice he will seek still every much in doubt.

The President said that even as he seeks to impose conservation on a reluctant nation he remains committed to a "healthy economic growth" and maintenance of "our standard" of living," predicting that an effective conservation program would create "hundreds of thousands of new jobs."

What seemed clear from his few concrete hints was that much of the sacrifice his energy proposals will entail will be financial in nature - in effect higher energy prices.

". . . Prices should generally reflect the true replacement cost of energy," the President said in outlining one of his principles. He said that the government will monitor progress toward reaching the 1985 goals and that stricter conservation measures will be imposed if the progress is not satisfactory.

This was an apparent reference to his proposed standby gasoline tax, not to exceed a total of 50 cents, to be imposed in 5-cent increments each year that gasoline consuption exceeded a pre-set goal.

"The citizens who insists on driving large, unnecessarily powerful cars must expect to pay more for that luxury," Carter said in another part of the speech, a reference to a proposed stiff gas-guzzler tax on new cars that fail to meet fuel efficiency standards.

Other parts of the energy plan that it is understood Carter will unveil Wednesday include:

A wide range of tax incentives for home insulation and energy conservation measures in business and industry.

Mandatory conversion to coal for utilities and industries that use oil and natural gas as a boiler fuel.

Abolishing the current "cost-of-production" base for natural gas pricing in favor of a "free-standing system what would set a price cap on all new natural gas, including intrastate gas. The gap would likely start at $1.75 per thousand cubic feet.

Allow domestic oil prices to rise, in two phases, to the world oil price now set by the 13-member Organization of etroleum Exporting Countries (OPEC) by imposing a tax on oil at the wellhead.

In attempting to set the political stage for his message to Congress Wednesday, the President siad there is little choice but to accept the sacrifice and inconvenience of an energy conservation program if the nation is to remain secure.

Citing figures that world oil comsumption will overtake production during the 1980s, he said the United States," can drift along for a few more years," the way it has in the past or it can "begin to prepare right now.

"We can decide to act while there is still time."