Solar cells are unlikely to generate more than one per cent of the United States' electricity until the next century, a panel of experts chaired by Henry Ehrenreich, Gordon McKay professor of Applied Physics said in a report released Tuesday.

Eventually, however, solar cells will probably be an important energy source, the report said.

The panel, sponsored by the Presidential Office of Technology Policy and the Department of Energy, studied the promises and problems of photovoltaics (solar cells.)

It also recommended that none of the many promising photovoltaic technologies should be pursued to the exclusion of the others. "Until one has (an economic) technology, one should look at all the possibilities," Ehrenreich said yesterday.

Although he emphasized the environmental advantages of solar electricity, Ehrenreich said that its cost would have to go down by about 20 times to be competitive with coal-generated electricity in the year 2000.

Reach For the Stars

Bruce Chalmers, retired Professor of Metallurgy and a photovoltaic researcher, said yesterday that some experts in the field believe that economic solar electric technologies are "within reach" and might be available by 1985.

Chalmers also said that growth of the solar contribution to electricity generation beyond the one per cent figure cited by the Ehrenreich study might be possible if the government provided a guaranteed market at a guaranteed price to the solar industry.

Such government action is not unprecedented, Chalmers said, citing the example of the armaments industry.

Guns and Volts

He added that such action is justified in the photovoltaic industry by the "urgency" of the energy problem, which he said might make waiting for the natural development of the industry disastrous. "There's much more danger from a shortage of energy than there is from the Russians," he said.

Chalmers did say that Ehrenreich's panel "may well be right" about how much energy solar electricity will actually contribute in the year 2000, but added that the government guarantees he suggested could result in much greater contribution.

Chalmers, Ehrenreich, William A. Shurcliff, honorary research associate in the physics department, and Henry Kendall, MIT professor of physics and a founder of the Cambridge-based Union of Concerned Scientists all agreed yesterday that non-electric solar technologies such as direct heating and cooling would make more significant contributions to energy production than solar cells before the year 2000.

Only Estimates

Kendall said that non-electric forms of solar energy might supply about 10 per cent of total U.S. energy demands by the year 2000.

Ehrenreich said that he is "bullish" on photovoltaics and that his panel's report has been regarded as optimistic about the long-term prospects of solar electricity. He noted that the Office of Management and Budget, with knowledge of the report's conclusions, has increased the budget for photovoltaics about 25 per cent.