IS SOLAR ENERGY WITHOUT WASTES?

Both statements are untrue. The resources used up in constructing solar energy facilities are immense, once again because of the diluteness of solar energy. At a recent conference on environmental impacts Kathryn A. Lawrence, a scientist with the national Solar Energy Research Institute in Golden, Colorado, gave some figures for various types of solar energy facilities. For example, for a thermal central receiver system of 1000 MW electric output capacity would use up the following quantities: 35,000 tons of aluminum; 2 million tons of concrete; 7,500 tons of copper; 600,000 tons of steel; 75,000 tons of glass; 1,500 tons of chromium and titanium (from the USSR, of course, for Rhodesia does not respect human rights); a cool 5 tons of silver; and more.

Frankly, we were shocked at these vast amounts and we checked them against the data in other sources, such as the report by the Governor of Oregon's Energy Task Force (which is as biased against solar energy as Andrew Young is biased against Cuban troops in Africa), and the figures given there work out to three times larger amounts.

And these resources don't come cheap. We don't mean dollars, of which the government can print any amount and recoup the cost by putting its citizens into higher tax brackets by the resulting inflation; we mean the energy needed to produce these materials. Again using the Oregon figures, this amounts to 75 million BTU per ton of aluminum, 56 million BTU per ton of steel, 18 MBTU/ton of glass, and 12 MBTU/ton of concrete.

Note that this is for a central receiver station, which produces the 1,000 MW of electricity all in one place; if these 1,000 MW are distributed in piddling little bits of 3 or 5 kW at a time, the use of resources and energy is, of course, very much greater for much the same reason as MacDonalds uses less oil to make a ton of French fries than 4,000 housewives who also collectively make a ton, but only half a pound each.

"Typical AtE slant ! " we can hear some readers saying. "As if a conventional power plant didn't use up steel and concrete and glass and other construction materials!"

Of course they do; but about 1,000 times less for the same power output. Once again we have arrived at the difference between concentrated and dilute energy. A nuclear reactor would (without auxiliary facilities) fit into the gymnasium of most schools; a solar plant of equal capacity (again without auxiliary facilities) would extend over many square miles of collecting area.

Specifically, for the same power output, a solar plant needs 1,056 times more structural metal (by weight) than a nuclear plant, and the ratio is roughly the same for fossil burning plants. The one material of which a nuclear plant needs much more than a fossil fired one is concrete (due to the large and massive containment building); but even here it needs 520 times less than a solar plant of the same power output.

Mind you, resource and energy use on a vast scale need not in itself be bad and is no reason to condemn solar power; what is reprehensible is the attempt to palm off solar power as a "soft" technology that has no environmental impact.

[More: "Review of the environmental effects and benefits of solar energy technologies," available to AtE readers from K.A. Lawrence, SERI, 1536 Cole Blvd., Golden, CO 80401.]