National Grid plc transmits and distributes electricity and gas. The company operates through UK Electricity Transmission, UK Gas Transmission, UK Gas Distribution, and US Regulated segments. The UK Electricity Transmission segment owns and operates high voltage electricity transmission networks in Great Britain. It operates an electricity transmission system of approximately 7,200 kilometers (kms) of overhead line, 1,500 kms of underground cable, and 336 substations. The UK Gas Transmission segment owns gas transmission network in Great Britain and liquefied natural gas (LNG) storage facilities in the United Kingdom. This segment operates a gas transmission system of approximately 7,660 kms of high pressure pipe and 24 compressor stations connecting to 8 distribution networks and third-party independent systems. The UK Gas Distribution segment operates gas distribution system in Great Britain. It operates approximately 133,800 kms of gas distribution pipeline in the United Kingdom. The US Regulated segment operates gas and electricity distribution, and high voltage electricity transmission networks in New York and New England, as well as electricity generation facilities in New York. It operates an electricity transmission network of approximately 14,355 kms of overhead line, 169km underground cable, 520 transmission substations, and 644 distribution substations; electricity distribution network of approximately 116,636 circuit kms; a network of approximately 56,263 kms of gas pipeline, as well as 781 kms of gas transmission pipeline; 50 fossil fuel-powered units on Long Island; and 4.6 MW of solar generation in Massachusetts. The company also owns Great Britain-France electricity interconnector and a 224 km interconnector between New England and Canada; and is involved in gas metering, property management, LNG import terminal, unregulated transmission pipeline, and LNG operations. The company was founded in 1990 and is headquartered in London, the United Kingdom.