Underutilization of solar energy

The sun's energy powers the living world. About ten to the eighteenth kilowatt-hours is received annually at the surface of the earth but only a tiny fraction of this energy is tapped directly for human use.
The use of solar energy usually has only slight environmental impacts but yields huge gains. Its proper utilization may lead to a reduction in consumption of other forms of energy; and in developing countries solar stills, driers, and other devices can bring about major improvements in the quality of life.
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(F) Fuzzy exceptional problems