The appointment consolidates all TV ads, its high-profile ITV weather sponsorship idents and rugby sponsorship marketing initiatives into one agency, in a bid to achieve better brand consistency.
Previously Soul handled creative for the weather idents and Miller Bainbridge, which retains below-the-line work, held the ad account.
Rainey Kelly fought off Delaney Lund Knox Warren for the business. TV ads will break later this year and the theme of the advertising will be taken through the line. John Evans, marketing director at Powergen, said Rainey Kelly's proposition "gets away from price competition, which consumers are fed up with", and would be "very different from the previous creative which used animated characters. Evans dealt with Rainey Kelly for six months when he worked at East Midlands Electricity.
German utilities firm E.ON acquired Powergen last month, but has denied reports that it plans to axe the Powergen brand.