In March1990, twelve Regional Electricity Companies (RECs) in England and Wales, known by law as public electricity suppliers, were formed as part of the restructuring of the electricity industry in England and Wales, prior to privatisation. In England and Wales the Central Electricity Generating Board was responsible for the generation and transmission of electricity, while 12 Area Electricity Boards (AEB) were responsible for distribution and supply to consumers. In Scotland the structure was different with all aspects of generation, transmission, distribution and supply being carried out by two vertically integrated companies.
See more at Wikipedia.org...