||Reliable, cleaner than coal and has lower C02 emissions. Very cheap in the 1990s, reliance on it grew fast. UK has North Sea reserves.
||CO2 emissions are significant. Domestic reserves are running out so growing dependence on imports means increasing vulnerability to rising prices and instability in gas-producing regions.
||Reliance on gas to continue, with UK now a net importer. Imports likely to account for 80% of total annual gas demand by 2020, based on existing policies, but plans to maximise recovery of existing reserves.
||Well established, cheap, reliable. UK has large reserves. Prices are rising, but slower than for gas and oil. Emissions of SO2 (which causes acid rain) have declined rapidly over last 20 years.
||High emissions of CO2 and SO2 remain a concern. Economically viable UK coal will run out in 10-15 years and is already expensive to mine. Half the coal used in the UK is imported.
||Cleaner coal technologies used in new coal-fired power stations, which will also use carbon-capture and storage when financially viable. Economic recovery of remaining reserves to be maximised.
||Minimal C02 emissions after construction. Efficient, effective and reliable. Not as vulnerable to fuel price fluctuations as oil and gas.
||Cost of building and decommissioning reactors, problem of nuclear waste and concerns about safety. Planning and building a power station takes at least 10 years so will not help meet Kyoto targets.
||All but one of UK's nuclear power stations to be phased out by 2023. Govt now backing new ones to reduce carbon emissions and safeguard supplies.
||No CO2 emissions, no vulnerability to fuel price or political instability. Very cheap once dam has been built.
||Natural flow hydro is reliant on rainfall and vulnerable to drought. Pump storage hydro relies on off-peak electricity to pump water back uphill. Environmental and social impact of large dams.
||Much of UK's hydropower potential already exploited. Large-scale future development unlikely, but use of smale-scale systems may increase.
||Landfill sites give off methane, a greenhouse gas 20 times more potent than C02, and burning it reduces its contribution to climate change.
||Burning methane still releases carbon dioxide and also nitrogren oxide gases.
||Already in use, but future supplies of landfill gas will be limited if waste reduction policies are effective.
||Reliable technology, well established.
||Inefficient generation, price instability, dependence on politically unstable regions, CO2 emissions.
||Oil makes a small and declining contribution to electricity generation in UK, but is the most important vehicle fuel.
||Energy crops considered carbon neutral because carbon released when crops are burned is balanced by carbon absorbed from atmosphere during growth. Suitable crops could be grown in UK.
||Space required to grow crops, impact on landscape. Release of greenhouse gases in harvesting and transport of crops. Particulates and hydrocarbons given off during combustion.
||A few facilities burning biofuels such as waste wood products and straw are already operating. Energy crops could be grown in UK, but some will not be cost effective unless yields improve.
||Renewable, not vulnerable to fuel price fluctuations. Some say UK has best wind resources in Europe. Turbines are emissions free and quick to build.
||Local opposition and concerns about noise and impact on landscape. More expensive than fossil fuels. Wind levels fluctuate.
||Fastest-growing renewable in the UK. Strong government support, seen as key to target of 20% renewable electricity by 2020. But progress limited by availability of suitable sites and higher-than-expected costs.
||Free and renewable energy source. Can generate electricity from photovoltaic cells, be used to heat water directly, or be maximised by good building design.
||UK sunshine is unreliable and limited. Solar power is confined to daylight hours unless photovoltaic cells are used to store power in batteries.
||Capacity small but developing. Government estimates solar could be economically competitive by 2020-30. Cheaper if integral to design of new buildings.
|Wave and tidal
||Renewable, parts of UK have strong potential.
||Development costs, potential environmental changes in tidal basins.
||Wave power several years behind wind in development terms. Tidal a "significant untapped source", according to government. Investigating number of locations and technologies.