Power NI continues to dominate the domestic market despite five years of competition. Its biggest rival is SSE Airtricity which supplies twenty one per cent of households. A long way behind but growing fast is North West based Budget Energy which has eight per cent. While it has a few thousand prepayment customers its attraction by far has been to keypad users. Electric Ireland, despite the backing of Ireland’s biggest energy firm, the semi state owned ESB, has made little inroads into the NI market.