Environment - Energy

1. Wind farms have been developed to create energy from the wind.

2. Wind turbines usually have three blades that turn between ten and thirty times a minute.

3. The blades face into the wind, which forces them to go round

4. The movement spins a shaft inside the turbine, which is connected to a generator that produces electricity

5. Wind farms do not produce any pollution and the land around them can still be used for farming.

6. Wind farms are however, quite expensive to run and some people think they spoil the landscape.

7. Hydro-electric power stations are used to create energy from water.

8. A dam is built to trap the water and then water flows through tunnels into the dam to turn the turbines and drive the generators.

9. Hydro-electric power stations can produce a great deal of electricity very cheaply.

10. The water arrives at the turbines at high pressure and flows away down river as normal.

11. The advantages of this method are that the water is free, there is no waste or pollution and electricity can be generated constantly.

12. One of the disadvantages is that dams are expensive to build.

13. Building a dam may also affect habitats and water quality and quantity downstream.

14. Waves are made by the wind as it blows across the sea and are a powerful source of energy.

15. It is very difficult to harness this energy and convert it into large amounts of electricity.

16. Wave power stations are very rare.

17. Once a wave power station is built, the energy is free; it needs no fuel to operate it and it produces no waste or pollution.

18. Wave power stations would need to cope with the roughest conditions at sea and be able to generate electricity from small waves.

19. The sun is the primary source of the Earth’s energy.

20. Solar energy is safe, efficient, does not cause pollution and is limitless.

21. It is, however, expensive to build solar stations, although some people do have solar panels added to their homes.

22. Solar cells can convert light directly into electricity to be used to power light bulbs.

23. Heat from the sun can be used to heat water in glass panels on the roofs of houses.

24. This means less gas and electricity is used in the home.

25. Geothermal energy has been used for many years in some countries for cooking and heating.

26. The word geothermal comes from two Greek words, ‘geo’, meaning ‘earth’ and ‘thermal’, meaning ‘heat’.

27. The temperature of the centre of the earth is about six thousand degrees Celsius.

28. Hot rocks underground produce steam which heats water.

29. Holes are drilled into the ground, the steam rises and, after being purified, is used to power turbines, which drive electric generators.

30. One of the problems of geothermal stations is that hazardous gases may come up from underground.

31. Nuclear power is power generated using uranium, which is a metal.

32. It produces huge amounts of energy from small amounts of fuel, and does not produce smoke or carbon-dioxide.

33. Although not much waste is produced, radioactive waste is very dangerous.

34. It must be sealed up and buried for a long period of time.