Abstract
The Electricity Supply Industry (ESI) in the UK was nationalised in 1947 and remained so until privatisation in 1990. On Vesting Day (31 March 1990) the nationalised ESI in England, Wales and Scotland was replaced, in accordance with the 1989 Electricity Act, by 19 separate undertakings. In England and Wales these successor companies comprised the 3 generating companies (National Power, PowerGen and Nuclear Electric), the 12 Regional Electricity Companies (RECs) for supply and 1 Transmission Company (the National Grid Company plc) which included the 2 Pumped Storage stations. By the end of 1996 the power stations in England and Wales will be made up of almost 60 centrally despatched power stations (not including auxiliary gas turbines). Thirteen of theses will be owned by non successor companies. The NGC transmission system has a central role linking the generators and the suppliers in the ESI in England and Wales. The transmission is developed to meet the power flows of the NGC customers who use its transmission system to exchange electrical energy. NGC are required under Condition 10 of the Transmission Licence to annually produce a Seven Year Statement covering the seven succeeding financial years. This provides a detailed forecast of customers electrical demand and their view of the generation capacity expected to be available in each of the seven years and provides a view of the generation margin and the power to be transported from one area to another. The paper briefly examines the developments that have taken place since privatisation, the customer forecasts of generation and demand and identifies the uncertainty associated with planning the development of the transmission system to meet future customer needs.
