A council leader has written a letter to the government urging them to consider allowing a barrage to be built on the River Severn.
A barrage could supply 7% of the UK's energy needs
A barrage on the river, with the second highest tidal range in the world, could provide 7% of the UK's energy needs.
More than 100 people who attended a recent conference on the subject are backing the letter from Peter Bungard from Gloucestershire County Council.
The letter asks for a "strategic evaluation" on a barrage plan.
Mr Bungard's plea also states that a barrage is one of "several other ways energy could be harnessed from the river" and calls for an investigation into other possibilities.
But environmentalists say a barrage would cause "irreversible damage" to wildlife.
The estuary is a special area for conservation and provides food for more than 63,000 migratory and wintering water birds.