What is renewable energy?

Renewable energy comes from sources that won’t run out and which don’t add to the greenhouse gases which cause global warming. These include:

Wind, which has been used for centuries to power everything from sailing boats to windmills. Wind energy is used to generate electricity using turbines that can be placed either in windy areas on land (onshore) or out at sea (offshore). At the moment, wind is one of the most technologically advanced forms of renewable energy. By 2010, it could be generating about 7.5% of the UK’s total electricity supply.
Sunlight, which can be turned into electricity using photovoltaic cells. These cells are placed in solar panels, which can be installed on the roofs of buildings, for example. Photovoltaic technology has become much cheaper and more efficient in recent years.
Water, including hydroelectric projects on dams and rivers, but also wave and tidal energy. The last two are particularly promising, and intensive research is now being carried out into how best to harness the power of the oceans. Various types of floating and fixed wave turbines are being tested, some off them off the Cornish coast.
Biofuels. These include any fuel that derives from recently living organisms – most often plants, but also manure and even human sewage and other forms of waste. Because the carbon in biofuels was recently extracted from atmospheric carbon dioxide by growing plants, burning it does not add to the overall CO2 in the Earth's atmosphere. About 15% of the world’s energy now comes from biofuels, and research is focussing on new ways of harnessing these.
Geothermal energy, which comes from the earth’s own natural heat. Using special heat-exchange technology, geothermal systems extract heat from deep beneath the surface of the earth. This can be used to warm buildings for example, though the technology has not yet been developed to convert geothermal energy into electricity on a large scale.

Nuclear energy isn't usually thought of as renewable, as it uses material which is not limitless. Unlike renewable energy, nuclear power plants create extremely hazardous waste that causes long-term safety problems. Allowing nuclear technology to spread also increases the danger of nuclear materials falling into the wrong hands.

The government has set a target of 10% of the UK’s electricity to be generated from renewable sources by 2010, as part of its commitment to cutting greenhouse gas emissions. By switching to a renewable electricity tariff, you’ll be helping to make sure that we stay on track towards this target and that renewable energy sources continue to be developed, enabling the world to escape the worst consequences of global warming.