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Science

Generating electricity

Electricity is a very convenient form of energy that can be generated using different energy resources. Some of these resources are renewable and some are non-renewable. Each resource has advantages and disadvantages.

Fossil fuels

The fossil fuels are coal, oil and natural gas. They were formed from the remains of living organisms millions of years ago and they release heat energy when they are burned. They are non-renewable.

Chemical energy stored in coal. This energy is transferred as heat and this energy is stored in water as steam. The energy in steam is transferred to movement in a turbine and to electrical energy in the turbine.

Energy transfer for the generation of electricity from a fossil fuel

About three-quarters of the electricity generated in the UK comes from power stations fuelled by fossil fuels. This diagram shows an energy transfer diagram for the generation of electricity from a fossil fuel such as coal.

Disadvantages of using fossil fuels

Fossil fuels are non-renewable energy resources: their supply is limited and they will eventually run out. Fossil fuels do not renew themselves, while fuels such as wood can be renewed endlessly.

Coal and oil release sulfur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain.

Fossil fuels release carbon dioxide when they burn, which adds to the greenhouse effect and increases global warming. Of the three fossil fuels, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least.

Carbon capture

Carbon capture and storage is a way to prevent carbon dioxide building up in the atmosphere. It is a rapidly evolving technology that involves separating carbon dioxide from waste gases. The carbon dioxide is then stored underground, for example in old oil fields or gas fields such as those found under the North Sea.

Back to Mains electricity index

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