Solar Energy Facts
Friday, 07.13.2007, 10:31pm (GMT)
Most power plants in the United States and all over world are using
fossil fuels to operate and generate electricity. They have been used
as an energy source as long as man has learned to generate power. These
traditional fuel sources have been around for ages and when man started
using this energy sources no one though about the consequences. Fossil
fuels will eventually run out and there will be a shortage of it in
near future. This shortage in will have its affect on our daily live
and various industries. Today we see some of these affects already,
prizes are raising and electricity is becoming more expensive. Although
these fuels are more scares, the need will still be here and will not
decrease in near future. To solve this shortage we will need to look
for other possibilities for our energy demand.
Fortunately, alternative energy sources are growing in interest. For
instance, locations with high water falls are experimenting on building
a hydro-electric power plant, which turns out to be successful. Other
locations with high wind speed make use of a power wind mills that can
convert wind power into electricity. Also thermal and tidal powers are
good alternatives.
Solar energy is also one of the energy sources that is gaining in
interest. This form of energy has steadily been growing. Today it is
widely used in the US and other parts of the world and the advantages
are numerous. Our solar energy source, the sun, its life span is
estimated to be another 4.5 billion years. It is fair to say that this
energy source is almost endless.
Rate of Energy from the Sun
The sun's radiation reaches a certain unit of area in space in the
region of the Earth's orbit and is estimated to be at 1,400 watts per
square meter. Out of this, photovoltaic cells (also known as solar
cells) can capture 19 to 56 watts per square meter (for 15% efficiency)
or an equivalent of 0.45 to 1.35 kilowatt per hour (kWh) in an annual
day and night average.
Therefore, if there would be more area that will be covered by several
solar panels, these panels can produce slightly more energy in the form
of electricity than what is currently available from oil, gas, and
other sources of energy combined (assuming 8% solar cell efficiency).
Conversion of Solar Energy
There are two ways of conversion of solar energy. First is the direct
solar energy which involves only one conversion into a usable form. For
instance:
* Sunlight hits the solar cell, converting it into electricity.
* Sunlight hits the absorber surface of a solar thermal collector,
converting into thermal energy which can be used to heat homes during
cold season.
The second is the indirect solar energy which involves more than one conversion to reach a usable form. For instance:
* Plants use photosynthesis to transform solar energy to chemical
energy, which can be burned later as fuel to generate electricity (also
known as bio-fuel technology).
* Hydro-electric dams and wind turbines are indirectly supplied by
solar energy through its interaction with the Earth's atmosphere.
Pros and Cons of Solar Energy
Just like any other types of energy resources, this energy source has its pro's and cons.
Pros:
* Pollution-free.
* Solar facilities can be run with little extra input or maintenance.
* It is abundant. As mentioned earlier, most of the inhabited areas here on Earth can be reached by sunlight.
Cons:
* Although it is abundant, some areas receive little sunlight. Thus,
power that will be produced in these locations is a minimum.
* Only available during daytime, thus a need to conserve to energy for use in night time.
* Photovoltaic cell technologies generate direct current (DC) power
which needs to be converted to alternating current (AC) power used in
distribution grids.
Once massive development of the use of solar energy is materialized,
expect that every household or industry in the world will now be
powered by solar energy. It is not just a dream, it will be a dream
come true.
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