Solar Energy                     


We've used the Sun for drying clothes and food for thousands of years, but only recently have we been able to use it for generating power.
The Sun is 150 million kilometres away, and amazingly powerful.
Just the tiny fraction of the Sun's energy that hits the Earth (around a hundredth of a millionth of a percent) is enough to meet all our power needs many times over.
In fact, every minute, enough energy arrives at the Earth to meet our demands for a whole year - if only we could harness it properly.


How it works

There are three main ways that we use the Sun's energy:-

Solar water heating , where heat from the Sun is used to heat water in glass panels on your roof.This means you don't need to use so much gas or electricity to heat your water at home.
Water is pumped through pipes in the panel. The pipes are painted black, so they get hot when the Sun shines on them. This helps out your central heating system, and cuts your fuel bills.
Solar heating is worthwhile in places, where you get lots of sunshine.


Solar Furnaces, use a huge array of mirrors to concentrate the Sun's energy into a small space and produce very high temperatures.

Solar Cells (really called "photovoltaic" or "photoelectric" cells) that convert light directly into electricity. In a sunny climate, you can get enough power to run a 100W light bulb from just one square metre of solar panel. This was originally developed in order to provide electricity for satellites, but these days many of us own calculators powered by solar cells.
Solar cells provide the energy to run satellites that oribt the Earth. These give us satellite TV, telephones, navigation, weather forecasting, the internet and all manner of other facilities.

Advantages

  • Solar energy is free - it needs no fuel and produces no waste or pollution.
  • In sunny countries, solar power can be used where there is no easy way to get electricity to a remote place.
  • Handy for low-power uses such as solar powered garden lights and battery chargers

Disadvantages

  • Doesn't work at night.
  • Very expensive to build solar power stations. Solar cells cost a great deal compared to the amount of electricity they'll produce in their lifetime.
  • Can be unreliable unless you're in a very sunny climate. In the United Kingdom, solar power isn't much use except for low-power applications, as you need a very large area of solar panels to get a decent amount of power.
 
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