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Solar Energy
Our Sun, one of more than 100 billion
stars in our galaxy, is the largest object in the solar system. Each second
it converts about 700 million tons of hydrogen into 695 million tons of
helium, with the lost 5 million tons of mass producing heat and light
energy. The Sun is about 4.5 billion years old and since its birth it used
up about half of its hydrogen in its core. The remaining hydrogen should
last for about 4-5 billion years.
Solar technologies directly
utilise energy from the sun. Solar technologies include:
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Photovoltaic systems - convert
sunlight to electricity
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Solar thermal electric power -
convert sunlight to electricity via heating water and producing steam
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Solar hot water systems - heat
water for pools & buildings
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Solar space heating systems -
provide heat for buildings
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Passive solar heating -
buildings are designed to naturally collect & retain the sun's heat
Advantages
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Solar power is relatively
pollution free
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Facilities can operate with
little maintenance or intervention after initial set up.
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Solar power is becoming more
economical as production costs decreases and the technology becomes more
effective in energy conversion.
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Solar power is available to
approximately half the planet at any given moment.
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Solar power can be viewed as a
local resource because of regional climatic variances.
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Some countries, regions, etc
(such as island communities, desolate regions and ocean-going vessels) are
harvesting solar power as a viable energy resource.
Disadvantages
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The impact of environmental
pollution during manufacture and construction should be taken into account
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It is most practical in certain
areas with a favourable climate and latitude. (However some solar
applications, such as solar water heating, work well using non-focused
technology and indirect sunlight).
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The best placed locations for
solar power arrays tend to be far from areas of highest energy demand
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It is not available at night and
is reduced when there is cloud cover, decreasing the reliability of peak
output performance.
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It must be converted into some
other form of energy to be stored
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Solar cell technologies produce
DC power which must be converted to the AC power when used in distribution
grids.
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Solar Panels
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