Natural gas is a fossil fuel and thus a finite resource. It is formed when the prehistoric remains of animals and plants are buried and subjected to high temperatures and pressures for millions of years.
Natural gas is mostly methane. Nearly half of the electricity generated in the UK currently comes from gas-fired power stations: gas is burned to generate steam, which is used to drive a turbine connected to an electrical generator.
Gas-fired power stations can provide a flexible and reliable electrical output, but are fuelled increasingly by imported gas as UK North Sea reserves decline. The price of gas (and therefore of the electricity produced using it) is volatile, and can rise and fall sharply in response to international events outside UK control.
The reliability of gas as an energy source improves the reliability of our overall energy supply. When weather conditions restrict the ability of intermittent energy sources such as wind to generate electricity, gas-fired power stations can increase their output to make up the shortfall. This ensures there is always enough electricity being generated to meet demand.
Burning gas also emits greenhouse gases. Carbon Capture and Storage (CCS) technology could present a possible solution, but has not yet been proven to work on an industrial scale. CCS is also expected to increase the cost of constructing a gas-fired power station, and reduce its efficiency.
The UK imports a growing proportion of its natural gas, posing a potential risk to the security of our gas supply. UK energy companies have already begun to improve the security of their gas supplies.
It is likely that gas-fired power stations will remain part of the UK electricity generating mix for the foreseeable future, and in the longer term gas with CCS may play a prominent role.