Introduction to Solar
Solar Energy is the cleanest and most inexhaustible of all
known energy sources. Solar radiation is the heat, light and other radiation
that is emitted from the sun. Solar radiation contains huge amounts of energy
and is responsible for almost all the natural processes on earth. The suns
energy, although plentiful, has been hard to directly harness until recently.
Solar Energy can be classified into two categories, Thermal
and Light. Photo-voltaic cells (PV) use semiconductor-based technology to
convert light energy directly into an electric current that can either be used
immediately, or stored in a battery, for later use. PV panels are now becoming
widely used as they are very versatile, and can be easily mounted on buildings
and other structures. They can provide a clean, renewable energy source which
can supplement and thus minimize the use of mains electricity supply. In
regions without main electricity supply such as remote communities, emergency
phones etc, PV energy can provide a reliable supply of electricity. The
disadvantage of PV panels is their high cost and relatively low energy
conversion rate (only 13-15%). Thermal solar on the other hand has average
efficiency levels 4-5 times that of PV, and is therefore much cheaper per unit
of energy produced.
It works on light absorption principle and its performance is not dependent on
high temperatures or long periods of direct sunlight, Solar diffused radiation
is collected in the specially coated vacuum tubes and heat generated is transferred
to your solar cylinder even on cloudy days when temperatures are as low as
-28C, They have an overall efficiency rating of almost 80%. This type of system
can be used in the South Pole where ambient air temperatures can drop below -40
c.
Thermal energy can be
used to passively heat buildings through the use of certain building materials
and architectural design, or used directly to heat water for household use. In
many regions, solar water heaters are now a viable supplement or alternative to electric or
gas hot water production.
Thermal energy obtained from the sun can be used for a
number of applications including producing hot water, space heating and even
cooling via use of absorption chilling technology.
Using solar and other forms of renewable energy reduces reliance on fossil
fuels for energy production, thus directly reducing CO2 emissions.
CO2 emissions contribute to global warming, an
environmental issue which is now of great concern. The average household can
reduce CO2 emissions by as much as 20% by installing a Solar Collector.