Natural gas gets from entry points and storage facilities to your home through the National Transmission System and regional distribution networks. This section explores the distribution component of the natural gas supply chain.
What is a gas distribution network?
Natural gas exits the National Transmission System through 175 off-take points throughout the United Kingdom. It then enters local distribution zones (LDZ).
Before flowing through distribution networks, natural gas has to go through pressure reduction stations. Gas is cooled by up to 40°C then transported to lower pressure sites.
To ensure there is always gas available to customers, some natural gas is stored in low pressure holders in each gas distribution network.
Natural gas then runs through low-pressure pipelines of different sizes depending on the end user:
- Industry: 600mm wide
- Business: 300mm wide
- Local: 180mm to 20mm (gas meter)
Gas distribution networks are also responsible for maintaining local gas systems and ensuring system safety. They are the companies to call if a gas leak is suspected, for instance.
Gas distribution networks in brief
There are eight gas distribution networks in Great Britain operated by four gas distribution network operators and six independent gas transporters directly connected to distribution networks.
The National Grid
As well as managing the National Transmission System, the National Grid delivers gas to 10.9 million customers in four gas distribution networks: the North West of England, the East of England (East Anglia and East Midlands), the West Midlands and London. That is a total of over 131,000km of gas pipelines.
Northern Gas Networks
Northern Gas Networks delivers gas to 2.7 million customers in three distribution networks: the North East, Northern Cumbria and Yorkshire. That is a total of 37,00km of gas pipelines.
Wales and West Utilities
Wales and West Utilities delivers gas to 2.5 million customers in two distribution networks: Wales and the South West of England. It has a network of over 35,000km of gas pipelines, covering an area of over 42,000 sq km.
Scotia Gas Networks
Scotia Gas Networks delivers gas to 5.8 customers throughout Scotland (Scotland Gas Networks) and Southern England (Southern Gas Network). That makes it the UK’s second-largest gas distribution company with its 74,000km of gas pipelines.
Independent gas transporters
Independent gas transporters deliver gas to around one million customers throughout the UK. Their distribution areas are included in gas distribution networks, so they have no regional monopoly. IGTs tend to connect and deliver gas to new developments (housing and commercial). The UK’s IGTs are:
- GTC Pipelines
- Independent Pipelines
- ES Pipelines
- Fulcrum Pipelines
- SSE Pipelines