20 Nov 2017
National Grid Electricity System Operator
National Grid are an international electricity and gas company based in the UK and northeastern US. We play a vital role in connecting millions of people safely, reliably and efficiently to the energy they use. National Grid Electricity has two roles in the United Kingdom: Electricity transmission owner We own the electricity transmission system in England and Wales. Our electricity assets comprise approximately 7,200 kilometres of overhead line, about 690 kilometres of underground cable and 337 substations at 241 sites. Electricity system operator We are the Great Britain System Operator, responsible for managing the operations of both the England and Wales transmission system that we own and also the two high voltage electricity transmission networks in Scotland. Day-to-day operation of the Great Britain electricity transmission system involves the continuous real-time matching of demand and generation output, ensuring the stability and security of the power system and the maintenance of satisfactory voltage and frequency. We are also designated as system operator for the new offshore electricity transmission regime.