Energy resources
There are different Useful supply or store of energy. in the world and the amount of The capacity for doing work. stored by them varies greatly. For example, the energy within 1 kg of naturally occurring uranium contains the same amount of energy as 14,000 kg of coal.
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Renewable or non-renewable?
Renewable resources are replenished either by:
- human action 鈥 eg trees cut down for biofuel are replaced by planting new trees
- natural processes 鈥 eg water let through a dam for Electricity that is generated by the movement of water. is replaced through the The continuous movement of water on, above and below the Earth.
A non-renewable energy resource is one with a Something that has a limited number of uses before it is depleted. For example, oil is a finite resource. amount. It will eventually run out when all reserves have been used up.
Different energy resources
The table below shows the main features of the most common energy resources used today.
| Energy resource | Energy store | Renewable or non-renewable | Uses | Power output | Impact on environment |
| Fossil fuels (oil, coal and natural gases) | Chemical | Non-renewable | Transport, heating, electricity generation | High | Releases CO2 (causes global warming). |
| Nuclear fuels | Nuclear | Non-renewable | Electricity generation | Very high | Radioactive waste (needs to be disposed of safely). |
| Bio-fuel | Chemical | Renewable | Transport, heating, electricity generation | Medium | 'Carbon neutral' so low impact. Although growing biofuels can take up land that could be used for farming. |
| Wind | Kinetic | Renewable | Electricity generation | Very low | Take up large areas that could be used for farming. Some people say wind turbines spoil the view and kill birds. |
| Hydroelectricity | Gravitational potential | Renewable | Electricity generation | Medium | Local habitats are affected by the large areas that need to be flooded to build dams. |
| Geothermal | Internal (thermal) | Renewable | Electricity generation and heating | Medium | Very low. |
| Tides | Kinetic | Renewable | Electricity generation | Potentially very high, but hard to harness | Tidal barrages can block sewage which needs to go out to sea. |
| Sun | Nuclear | Renewable | Electricity generation and heating | Dependent on the weather and only available during daylight | Very little. |
| Water waves | Kinetic | Renewable | Electricity generation | Low | Very low. |
| Energy resource | Fossil fuels (oil, coal and natural gases) |
|---|---|
| Energy store | Chemical |
| Renewable or non-renewable | Non-renewable |
| Uses | Transport, heating, electricity generation |
| Power output | High |
| Impact on environment | Releases CO2 (causes global warming). |
| Energy resource | Nuclear fuels |
|---|---|
| Energy store | Nuclear |
| Renewable or non-renewable | Non-renewable |
| Uses | Electricity generation |
| Power output | Very high |
| Impact on environment | Radioactive waste (needs to be disposed of safely). |
| Energy resource | Bio-fuel |
|---|---|
| Energy store | Chemical |
| Renewable or non-renewable | Renewable |
| Uses | Transport, heating, electricity generation |
| Power output | Medium |
| Impact on environment | 'Carbon neutral' so low impact. Although growing biofuels can take up land that could be used for farming. |
| Energy resource | Wind |
|---|---|
| Energy store | Kinetic |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation |
| Power output | Very low |
| Impact on environment | Take up large areas that could be used for farming. Some people say wind turbines spoil the view and kill birds. |
| Energy resource | Hydroelectricity |
|---|---|
| Energy store | Gravitational potential |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation |
| Power output | Medium |
| Impact on environment | Local habitats are affected by the large areas that need to be flooded to build dams. |
| Energy resource | Geothermal |
|---|---|
| Energy store | Internal (thermal) |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation and heating |
| Power output | Medium |
| Impact on environment | Very low. |
| Energy resource | Tides |
|---|---|
| Energy store | Kinetic |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation |
| Power output | Potentially very high, but hard to harness |
| Impact on environment | Tidal barrages can block sewage which needs to go out to sea. |
| Energy resource | Sun |
|---|---|
| Energy store | Nuclear |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation and heating |
| Power output | Dependent on the weather and only available during daylight |
| Impact on environment | Very little. |
| Energy resource | Water waves |
|---|---|
| Energy store | Kinetic |
| Renewable or non-renewable | Renewable |
| Uses | Electricity generation |
| Power output | Low |
| Impact on environment | Very low. |
Comparing resources
Power stations that use Natural, finite fuel formed from the remains of living organisms, eg oil, coal and natural gas. or nuclear fuel are very reliable sources of energy. These two types of stations provide most of the country's electricity. They operate almost continuously. When additional power is needed, gas power stations or hydroelectric power stations are usually used because they will come on very quickly and start generating electricity almost immediately.
The fuel for nuclear power stations is relatively cheap but the power stations themselves are expensive to build. It is also very expensive to dismantle, or To deactivate or remove in a safe manner., old nuclear power stations at the end of their useful life and the highly When unstable atoms give off particles that can be harmful to humans. waste needs to be stored for millions of years before the natural The number of decays of a radioactive element per second. Measured in Becquerels (Bq). will reduce to a safe level.
Water power, eg tidal and Electricity that is generated by the movement of water. , are reliable and predictable because of the Moon causing the tides and rainfall filling reservoirs. These two can also be used to supply additional demand. But many of the renewable sources are unreliable, including wind and solar energy, and cannot respond to increased demand - sunny and windy weather cannot be guaranteed.
Renewable resources have no fuel costs, but the equipment used is expensive to build.
Electricity generation
Generators in a power stations produce electricity when a coil of wire is in a changing magnetic field. This changing magnetic field is caused by spinning a magnet inside the coil.
Fossil fuel and nuclear power stations use the energy store to heat water and produce steam to turn a turbine which is connected to the magnet, causing it to spin.
Other energy sources are directly linked to the generator.