The placing of solar panels on the rooftops of Peterborough houses will go ahead after approval at full council.
The scheme will initially be trialled in a few roads and if successful will be extended throughout the city.
He indicated £6 million of savings could be made.
There was enthusiasm for the scheme but councillors referred to a failed £3 million solar farm project on fields at Newborough and Thorney as reasons to be cautious.
Cllr Chris Ash added he was worried the scheme could become over-ambitious.