Powergen will support the tie-up with an autumn press, radio and outdoor campaign through Rainey Kelly Campbell Roalfe/Y&R.
"This is our biggest marketing campaign of the year in terms of the priority and investment we have given it," said a Powergen spokesman.
Powergen head of business development John Lanagan, who reports to marketing director Paul Parmenter, is overseeing the link. The company sees ClubCard, which is used by ten million households, as a way of retaining as well as acquiring customers.
Powergen customers who register with ClubCard will earn one point for every £1 spent on gas and electricity.
Powergen acquired TXU Energi last October to become the UK's second-biggest utilities company behind British Gas. Tesco's relationship with the energy supplier began when Norweb Energi, which became TXU, joined ClubCard in 1998.