Solar energy

You’ve already heard of solar panels which use the heat energy from the Sun to heat water. Solar cells are different. They also use heat energy from the Sun but they’re able to convert this directly into electrical energy. They’re used for a range of applications, from calculators to satellites orbiting the Earth.

The advantages to solar cells are:

• – they’re renewable
• – they have no fuel costs
• – they don’t produce any harmful waster products
• – they can provide electricity in remote area

However:

• – they’re expensive to produce and inefficient which makes the cost of their electricity large
• – they’re unable to work at night

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Geothermal energy

Hot water and steam is produced deep within the Earth, This can be harnessed as geothermal energy and used to drive turbines. There are two main types:

• Volcanic regions: some rocks contain radioactive substances. When these substances decay heat energy is released. This heat warms up rocks and in volcanic areas these rocks sometimes then heat up water. The hot water rises up and produces steam which can then be used to drive turbines. Geothermal power stations currently exist in Italy, California and Iceland.

• Hot rocks: in some regions the rocks are hot but no hot water or steam is able to rise up to the surface. To get to the energy two deep wells are drilled into the Earth. Cold water is pumped down into one. When it reaches the rock it runs through the fractures and heats up. It then rises up through the second well as hot water and steam.

The main advantages of geothermal energy are that it’s a renewable source and no harmful waste products are created.

However, there are only a few regions where this energy can be found.

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Wind energy

Wind is created by huge convection currents which are pushed through the Earth’s atmosphere by the sun’s heat energy. As long as the sun continues to exist, so will wind energy which makes it a renewable source.

Wind provides a form of kinetic energy which is converted into electrical energy by wind turbines. Wind turbines consist of massive blades connected to a nacelle. In the nacelle is a generator. The generator is driven by the wind turning the blades. Wind turbines tend to come in groups which are known as wind farms.

The main advantage of wind energy is that it’s a renewable source and doesn’t produce any harmful waste products.

The disadvantages include:

• – they depend on wind so if there’s no wind then no electricity is produced
• – some people consider them eye sores and those living close to them find them noisy