Environmental Engineering Reference
In-Depth Information
Solar energy
Here comes the sun
Most forms of energy come from the sun. The notable exceptions
are geo-thermal energy (drawing heat from the earth's core) and
tidal power influenced by the moon. All plant life depends on the
sun; fossil fuels are plants that have fossilized into fuel; and biomass
is biological material. These are indirect sources of solar energy. But
of course there are more direct sources of solar energy - three in
particular.
Solar thermal
The sun's rays have been used for centuries to heat water - in this sense
solar thermal energy is nothing new. The most common modern process
of solar thermal technology involves heating tubes containing a liquid
which is pumped into a heat exchanger, which transfers the heat to a hot
water tank. It is a fairly simple technology, the use of which has increased,
but not to the extent that it deserves. It has, however, been taken up
enthusiastically by countries with sunny climates which also lack energy
alternatives - such as Israel, Cyprus and to some extent China. In the US,
the majority of solar
thermal energy is of
the low-temperature
variety - panels that
are used mainly for
heating swimming
pools.
Solar panels used
for heating water in
Santorini, Greece.
