Northern Ireland Electricity Networks Limited (NIE Networks) is the electricity asset owner of the transmission and distribution infrastructure in Northern Ireland, established in 1993 when the business was privatised. NIE Networks does not generate or supply electricity. Since 2010 it has been a subsidiary of ESB Group. NIE Networks has three transmission interconnectors with the transmission grid in the Republic of Ireland. The main interconnector was built in 1970 between Tandragee and Louth but The Troubles saw the interconnector destroyed in 1975 and left in that state for twenty years until repair. NIE Networks should not be confused with Power NI, its own former supply business, which was not part of the sale to the ESB and remains owned by Viridian. NIE Energy changed its name to Power NI on 25 July 2011, as ESB retained the NIE name in Northern Ireland. History Background Electricity supplies in Northern Ireland started in the early 1890s with the establishment of electricity undertakings by the Belfast and Londonderry City Corporations. The co-ordination of supplies took place in 1931 with the foundation of the Electricity Board for Northern Ireland. The ownership of the all public power stations in Northern Ireland was vested in the Electricity Board in 1949. Belfast Corporation Belfast Corporation Electricity Department gained the authority to generate and sell electricity under the provisions of the Belfast Electric Lighting Order 1890, confirmed by the Electric Lighting Orders Confirmation (No.7) Act 1890. The corporation's area of supply was 83 square miles with a population of 502,000 (1958). By 1958 there were three electricity generating stations at Belfast East, Belfast West and East Bridge. Belfast East power station (formerly Harbour power station) comprised eight turbo-alternator generating sets: 1 × 6 MW British Thomson-Houston, 2 × 15 MW, 1 × 18.75 MW and 4 × 30 MW Metropolitan Vickers, a total electricity capacity of 174.75 MW. These were supplied with up to 2,010,000 pounds per hour (253 kg/s) of steam from 18 Babcock and Stirling coal-fired boilers. Belfast West power station (formerly Victoria power station) comprised five turbo-alternator generating sets: 2 × 30 MW Parsons low pressure sets and 3 × 60 MW Parsons high pressure sets, giving a total capacity of 240 MW. The low pressure sets were supplied with up to a total of 540,000 pounds per hour (68 kg/s) of steam at 650 psi and 925 °F (44.8 bar and 496 °C) from