Mains gas
Mains gas is the natural gas that is distributed to buildings through a pipeline infrastructure. In the UK, mains gas is supplied to more than 21 million homes and is the most popular fuel for heating and cooking.
Natural gas is mainly methane (CH4), but it also contains ethane, propane and some heavier hydrocarbons as well as small amounts of nitrogen, carbon dioxide, hydrogen sulphide and traces of water.
While the gas itself is owned by individual gas suppliers, all gas passes through the National Grid’s transmission system on its route to end users. As the owner and operator of the UK’s gas transmission infrastructure, the National Grid work with the gas suppliers to ensure delivery.
The National Grid undertake safety checks on all gas being received in their reception terminals, and add an odoriser to enable leaks to be detected by smell as it's colourless, tasteless and odourless.
It is the responsibility of the National Grid to ensure that the gas leaves the transmission system and enters the distribution networks at high pressure, where it is then transported through various reducing pressure tiers until being delivered to the end user. The UK has 8 regional distribution networks, of which 4 are owned by the National Grid, and the other 4 by separate companies.
The main elements involved in mains gas are:
- Production and importation: Gas is extracted from offshore fields in the North and Irish seas. It is also imported from other countries as liquefied natural gas (LNG).
- Transmission: Reception terminals receive gas from producers, which is then supplied to the national transmission system after quality checks.
- Distribution: Gas is transported in the distribution networks.
- Supply: Gas is delivered to the end user through a pipe owned by the local distribution network.
Around 15% of people in the UK are not connected to the mains gas grid, which can mean that their heating options are limited and therefore relatively expensive (sometimes twice the cost of a mains gas supply).
Some of the alternatives to mains gas include:
- Liquefied petroleum gas (LPG).
- Heating oil.
- Wood.
- Coal.
- Electricity.
- Renewable sources such as heat pumps, biomass, solar thermal, and so on.
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