Imagine a perfect source of energy. One with which no pollution what-so-ever is
associated with. No poisonous gasses or destruction of rain forests. This
abundant source of energy comes from the sun. Solar energy is the visible energy
produced in the sun as a result of a constant nuclear fusion reaction that is
taking place. The amount of energy at the solar constant, which is at outer edge
of the earth's atmosphere, is two calories per minute per cm squared. A calorie
is the amount of energy needed to raise one gram of water one degree Celsius.
If we could efficiently harness the energy bombarding the earth for twenty-four
hours we could power New York for a year. Unfortunately the photovoltaic cells
that change the energy into electricity are so inefficient that it would take
twenty-five years to pay for it's self in output.
There many uses of solar energy. Some homes rely fully on the power of the sun
to heat their water. Other houses have flat plate collectors which aid in the
heating of the house and water. Solar Energy plays a vital role in the
absorption cooling cycle in a process called solar cooling.
Since wind is caused by the up and down movement of hot and cold air, wind
energy can be a branch of solar energy. The same thing with tidal energy. And