Power NI was the former customer supply business of Northern Ireland Electricity, known originally as NIE Supply and then after its separation from the rest of NIE, as NIE Energy. Both it and the Power Procurement Business "were separated from NIE on 1 November 2007 in accordance with the requirements of the 2003 EU Electricity Directive which required the independence of the distribution system operation function." In 2010 Viridian sold Northern Ireland Electricity, including the NIE name, to the Electricity Supply Board - the state-owned electricity company of Ireland. As a result, NIE Energy was no longer allowed to use the NIE name, and it rebranded as Power NI on 25 July 2011.