Solar Renewable Energy - Sun Power
Friday, 07.13.2007, 09:44pm (GMT)
It is no secret that the sun can be harnessed to provide a source of energy for homes and businesses.
The sun is a powerful star. It supplies us with energy, through a
process called nuclear fusion, and sustains life on our planet Earth.
Solar energy, or energy from the sun, has existed since prehistoric
times when men would magnify the sun's energy in efforts to start
fires.
The sun is a valuable resource that radiates enough energy on the
United States in one day to meet the nation's needs for one and a half
years. Since it is a free, clean and renewable source of energy, it is
an energy source that will play a vital role in our future.
Using the sun's energy for our energy source seems like an easy
solution to having an energy supply forever. Harnessing the suns energy
is where the problem lies. The sun's rays shine all over the world and
not in just one spot. Although it takes only 8 minutes for sunlight to
travel to the earth, trying to catch the rays over such a wide area can
prove to be tricky. Also, the energy in any one given place will vary
due to factors, such as, clouds and weather conditions.
The history of using solar energy began in 1890's when solar water
heaters were used in the United States. Solar water heating requires a
storage collector and a storage tank. Flat plate solar collectors are
mounted on rooftops. Pipes carrying water are pumped through these
collectors. The tubes are painted black so they will get hot quicker.
As the heat is collected the fluid in the tubes get heated. A storage
tank holds the hot liquid. This helps with central heating and cutting
fuel costs. Solar heaters became popular when natural gas was expensive
and burning wood and coals were burdensome. It's popularity diminished
with the discovery of an abundance of natural gas and oil deposits. Now
they are making a comeback to replace the depleting fossil fuels that
had taken its place.
Solar energy can be in the form of heat energy or light energy. The
technology of photovoltaic, or PV as it is commonly called, converts
the suns energy into electric currents through the use of solar cells.
These electric currents can be used instantaneously or stored for later
use. The PV cells consist of pieces of silicon under a thin piece of
glass. They have both a positive and negative charge. Simple examples
of this are the solar powered calculators that are common today. More
complex examples are solar panels placed on roofs. This consists of
using thin film solar cells as rooftop shingles, roof tiles, and even
glazing for skylights. Unfortunately, the cells generate only about one
sixth of the sun's energy into electricity. This means bigger arrays
are needed and along with this come larger costs.
Solar thermal power plants use the sun to heat fluid, which in turn, is
transferred into steam similar to fossil fuel burning plants. The steam
is transformed into mechanical energy in a turbine and electrical
energy from a generator. The downfall is solar plants cannot produce
energy on cloudy days.
It is expected the next few years will see millions of households using
solar energy. As research continues and processes improve, using our
sun as a renewable energy source will produce efficiency and cost
savings. So, let the sun shine in and take full advantage of this warm
energy source where you live.
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