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Solar Energy Technology and What Happened to It?

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Solar Energy Technology and What Happened to It?

Discussion of why homes and buildings are not powered by solar energy
despite the fact that the sun provides an unlimited supply of energy
for most of the world. Cost competitiveness is the key to its failure
so far. The solution is research and development that will lead to more
efficient solar technology.

If you’ve been keeping up with science and the
environment, you may wonder why solar energy hasn’t yet dominated the
world’s energy production technologies, given both the political and
environmental problems caused by dependence on oil and other fossil
fuels. There is a barely detectable presence of solar powered homes,
automobiles, and heating systems across the landscapes of the world,
which may seem strange considering the environmentally clean and
infinitely renewable nature of solar powered systems.

While the benefits of solar power are obvious and many, the current
state of solar technology still leaves this form of energy production
with significant competitive disadvantages. The majority of consumers,
when given a choice, will choose the least expensive form of energy. If
solar technology is going to replace oil, gas, and coal, it will have
to become less expensive to consumers. This translates into a
requirement for solar technology - it must become more efficient.

Just as wind-generated power can only be obtained when there is wind,
solar power can only be generated when there is sunlight. Clouds,
winter weather, and nighttime itself make solar power unavailable on
demand - it must be stored at the time it is generated for use during
these other unproductive periods. Storage technology, usually in the
form of batteries, adds to the already high capital investment required
for these systems. If solar power were the only form of energy
available, countries at high latitudes with perpetually cloudy weather,
unable to produce solar power on their own, would have to have energy
transported over long distances, raising costs even higher.

Solar power could be made cost effective if solar cells could be made
more efficient. When sunlight shines directly onto the semiconductor
materials used inside solar cells, a current is generated. This type of
photovoltaic system is seen most often on the faces of solar powered
calculators, whose energy requirements are extremely modest. The energy
conversion efficiency of a typical photovoltaic system is about 15%,
which means that only 15% of the solar energy striking a cell actually
gets converted into electricity. (For comparison, the energy conversion
efficiency of photosynthetic pigments in plants can be as high as 30%.)
Compared to 30%, the 15% efficiency of solar cells may not sound too
bad, but remember that solar energy technology is not competing with
plants, but with fossil fuel technologies which deliver power on a
low-cost, kilowatt-hour basis. Therefore, it is imperative that solar
cell technology advance to the point where its efficiency level
provides electricity more cheaply than it does today.

This goal can only be achieved through basic research in areas like
chemistry, materials science, and physics. If nature has made plants
30% efficient through random evolutionary processes, there is no reason
why scientists can’t do better with a committed research and
development effort.

By Lowell Parker

source : http://www.buzzle.com/articles/solar-energy-technology-and-what-happened-to-it.html

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