Abstract & Overview
2 of about 4 1/2 percent over the next couple of decades.This will mean that in twenty-four years the United States will need twice the amount of energy that is used today.This great need for energy, coupled with the increased cost of energy-especially the cost of Middle East oil-has finally awakened us to the fact that we need to find alter native sources of energy to that provided by fossil fuels.Some of the better known sources include: geothermal energy, wind energy, solar energy, and nuclear fusion.Of all these, solar energy offers the greatest potential.It is nonpolluting, has minimal environmental consequences, and is an unend ing and nondepletable source of energy.The purpose of this paper is to study solar energy and its application as a source of energy for the heating of homes.The paper starts with the definition of solar energy, followed by a brief history of its applications down through the years.The most recent uses of solar energy, including rooftop water heaters and the solar collectors used in the heating of homes, are also discussed.The main portion of the paper explains a basic solar energy system with collector, storage, heat exchange and asso ciated equipment, incorporating the most economical and effi cient features for the average home.This system will then be compared to the conventional heating systems of electric 2 John L. Moore, ed.. Continuing Energy Crisis in America (Washington, D.C.: Congressional Quarterly, Inc., 1975), p. 22. are only two openings or "windows" (in the atmosphere) through which the wave lengths reach the earth.One is called the "visible window" and the other the "radio win dow."^Only the visible window is pertinent here because through it the earth's surface receives ultraviolet, infra red, and visible light waves of the electromagnetic spec trum.These three basic parts compose 4 percent, 16 percent, and 80 percent, respectively, of the energy reaching the earth's surface.^Actually, the amount of energy the earth's surface receives from the sun can be considered infinite.As a plan et, the earth receives only two-billionths of the energy that the sun produces.^Only half of this is received on the sur face of the earth because the earth's atmosphere reflects the other half.This one-billionth of the sun's energy is equiva T 8 8 lent to 10 horsepower.In watts, the energy falling on the earth in a year is about 1.72 x 10^^ watts, a million times greater than all the electricity that was generated 9 in the United States in 1959.Alternatively, the energy received per acre each at the 25° latitude of the earth's ^Raymond A. Wohlrabe, Exploring Solar Energy (New York The World Publishing Co., 1966), p. 33.