Solar energy, many scientists believe, is adequate for all the conceivable energy needs of the world. It is safe and clean, but expensive. The main technical obstacle is bringing down the cost of the solar cells, which convert light from the sun directly into electric current. Simpler systems abound: solar cookers and ovens and water heaters.
Mother Earth News writes of a solar heat collector which turns water into steam, which in turn drives a small steam engine, which drives a generator, which produces electricity. Some experts say it would take no more than 10 years, with massive government support, to make solar energy practical. Others say 50 years is more likely.
