We are the sole owner and operator of gas transmission infrastructure in Great Britain.
In the US, we hold a minority interest in an interstate gas pipeline regulated by FERC.
Transmission systems generally include terminals, pipes, pressure reduction stations and compressor stations. They may also include storage facilities, including liquefied natural gas (LNG) storage. They connect sources of gas, e.g. offshore gas fields, through terminals and pipelines to the distribution systems.
Compressor stations located along the network play a vital role in keeping large quantities of gas flowing through the system, particularly at time of high demand. The gas transmission system has to be kept in balance, which is achieved by requiring gas suppliers to source more or less gas contracting with customers to reduce demand and/or using stored gas.
In the UK, gas leaves the transmission system and enters the distribution networks at high pressure. It is then transported through a number of reducing pressure tiers until it is finally delivered to consumers. There are eight regional gas distribution networks, four of which are owned by National Grid delivering gas to around 10.9 million customers on behalf of 37 shippers.
In the US, gas is delivered by the interstate pipeline companies to local distribution networks. Each local distribution company has a geographically defined service territory and is the only local distribution company within that territory. These companies are regulated by the relevant local state’s utility commission. We have gas distribution networks in Upstate and Downstate New York, Massachusetts and Rhode Island, serving around 3.6 million customers.
In the UK, we own and operate an LNG importation terminal and storage facilities at the Isle of Grain in Kent (Grain LNG). Grain LNG charges customers under long-term contracts for various services, including access to our importation terminal, storage facilities and capacity rights.
In the US, we own and operate LNG storage and vaporisation facilities to support our gas distribution businesses as well as an LNG storage facility in Providence, Rhode Island, where we store gas for third parties for a fee. We also buy gas directly from producers and LNG importers for resale to our customers.
Supply and metering
We do not supply gas in the UK. However, we own National Grid Metering, which provides meters and metering services to supply companies, under contract. In the US, metering is part of our distribution businesses.
In the UK, customers pay the supplier for the cost of gas and getting it to them. Suppliers pay shippers and we transport the gas through our network on behalf of shippers. It is these shippers who pay us transportation charges.
In the US, gas distribution companies, including National Grid, sell gas to consumers connected to their distribution systems.
In most cases in the US, where customers choose National Grid, they pay us for distribution and gas costs. Where they choose to buy gas from third parties, they typically pay us for distribution only and pay the third party supplier for the gas and upstream transmission cost.