Renewable fuels aren’t ‘free’

To the editor:

Regarding solar energy and the vain hope that it will provide substantial help in providing electricity for the U.S.

A few numbers are in order. About 1,000 watts of solar energy falls on every square meter of the earth’s surface every day. But we cannot collect it from ice-covered earth, nor from the oceans. This reduces the area by approximately 75 percent. The only way this energy is being collected now is through photosynthesis. The worldwide average of energy collection is around 170 watts per square meter. Why the difference between 1,000 and 170? The 1,000 is at the equator at high noon on a clear day. Northern forests collect about 0.1 watt.

Sugar cane is one of the best crops to store solar energy. It does so at a rate of about 1 watt per square meter. The loss in conversion of sugar cane to ethanol is about 50 percent, and this does not consider the energy needed in the conversion process.

All tropical areas are not suited to grow sugar cane. Mountains, deserts, poor soil, swamps, etc., will not do it, reducing the arable land by at least 50 percent. But to plant cane in the tropics, most of the tropical forest would have to be cleared, releasing untold amounts of CO2 when they are converted. Besides, what would the Sierra Club think? Tropical soils are not suited to growing the same crop year after year, so they would need untold quantities of fertilizer. And where does fertilizer come from? Petroleum, that’s where. Then there is the real problem of getting electricity from, say, Brazil to New York City, or wherever.

I recall at the end of World War II, electricity from atomic energy was being promoted by the old Atomic Energy Commission. Their theme was it would be too cheap to meter. And so it is with “free” renewable fuels.

Donald Bradley

Categories: Cook on Concord