What is it?
Solar energy comes from the Sun. It is a star that produces massive amounts of energy. Nuclear reactions in the Sun's core turn millions of tonnes of hydrogen into energy every second. The energy radiates into space. Travelling at the speed of light, a small fraction of this energy reaches Earth about eight minutes after it leaves the Sun.
How is it used?
Solar photovoltaic (PV) cells convert light energy into electricity. They can be arranged in panels and fitted to roofs and the sides of buildings.
Active solar water heating is an easy source of hot water. Fluid inside a black panel, tilted to face the Sun, heats up and is then circulated to the hot water tank inside the house. There, the heat is transferred to the household water system for use in the home.
Where can you find it?
Large-scale solar plants are only cost effective where there is lots of sunshine.
Advantages and disadvantages of using solar energy to generate electricity
- Solar energy is renewable and the Sun’s heat and light are free
- Solar energy can be used to generate electricity in remote places where other electricity supplies are hard to come by
- It does not produce any carbon dioxide, which contributes to the greenhouse effect
- Energy is usually generated at or near to the location it will be used. This keeps transmission and distribution costs to an absolute minimum
- PV cells do not work so well when it is cloudy and do not work at night
- The UK is not a very sunny country! Solar power works better in hot places, so its use is therefore limited
How many systems in the UK?
There are over 100,000 small solar heating systems in the UK, but very few houses have PV panels.
The UK climate is not suitable for it to become a major source, but it could still play a role in water heating systems and electricity generation for the home.
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