Alternative Energy

Hydroelectric Power Running water, either directly from a fast flowing river, or usually from a river that has been dammed, turns turbines in the power station. These turn generators that produce electricity that is then fed into the national system. Hydroelectric power (HEP) only forms about 8% of the world's energy production, but some countries rely on it almost exclusively. It has been introduced to developing countries, such as Brazil and Ghana; to help their industrial growth as well as being used in more developed countries like Norway and New Zealand.

Hydroelectric Power Requirements: The only requirement is a suitable, fast flowing river and an area to flood with the reservoir that is formed behind the dam. HEP schemes have to be in areas of consistently good rainfall. Advantages: It is a relatively cheap form of energy production, once the initial costs of building the dam have been met. The water can be used for other purposes as it just flows through the turbines and out the other side. It produces very little pollution. The reservoirs provide areas that can be used for tourism development. The dams can help to control the flood risk further down the river. Disadvantages: Not every country has suitable sites for the dam and reservoir. The reservoir may flood towns and villages, causing lots of people to have to re-locate. It may also flood prime valley- floor farmland. The dams are not things of particular beauty and so may spoil the natural environment.

Wind Power Wind power is being harnessed using massive modern wind turbines. In the past windmills have been used for power in places like Holland, but these new ones are quite different in shape. They stand approximately metres high, and are made of fibreglass. Wind Farms have been set up, like the one at Delabole in Cornwall, in many areas of the UK. Very simply the wind turns the turbine, which turns a generator, which produces electricity.

Wind Power Requirements: Exposed hilltops are the usual location for a wind farm. They need somewhere with a fairly constant supply of wind, so many in the UK are located either on the coast or in high moorland. With the exception of three, they are all towards the West of the country because the prevailing winds blow from the southwest. Advantages: Wind farms are cheap to run and produce very little pollution. Wind turbines take up very little space on the ground, so the land around them could still potentially be farmed. Disadvantages: They are fairly costly to set up. They produce only a small amount of electricity, although that is improving. The wind does not necessarily blow all the time. They are eyesores, spoiling the natural environment of the area. They can be noisy, disturbing local people. They disrupt TV signals in the area.

Solar Power Solar panels are used to convert the energy from the sun into power.

Solar Power Requirements: The most obvious one is that you need the sun. Countries like Australia are perfect for solar power as there is a fairly high chance of prolonged sunshine. The UK would not be so suitable. Many developing countries in Africa could potentially make good use of solar power. Advantages: It is a limitless supply of energy, that is completely pollution free. It is a very efficient form of energy production. Disadvantages: You need the sunny conditions. It is expensive to set up and at the moment really can only produce a minimal amount of energy. Winter, when more energy is needed, does not have as much sun as the summer.

Geothermal Power Countries like New Zealand and Iceland have exploited their natural resources to use geothermal energy. Water is piped down in to the ground in areas where volcanic activity is close to the surface. The water is heated and turns to steam. This is then used to turn turbines, which turn generators and produce power.

Geothermal Power Requirements: There is only one main requirement, and that is that the area must be one where volcanic activity means that the rock near the surface is heated. If this occurs, the being beside a river is beneficial because of the need for water. Advantages: It is a completely renewable source of energy, using only the heat of the Earth and water. It is pollution free and does not change with the season, as some of the other sources do. Disadvantages: It is a very costly form of energy to set up. A volcanic area is needed. Volcanic areas are susceptible to not just eruptions, but also earthquakes, so the power station may be in a dangerous area.