Proposals for a giant water wheel stretching across the River Mersey are due to be revealed.
If plans get the all-clear a pilot project could go ahead
The river is one of the best sites for renewable energy created by tides, in the UK, a new study claims.
The report claims the Mersey's unusual shape and wide range of tides can be used to produce environmentally- friendly power.
If the plans get the go-ahead, the wheel turbine could produce enough electricity for half a million homes.
The study was sponsored by Peel Holdings, who operate the Mersey Docks and Harbour Company, and the North West Development Agency.
Professor Peter Guthrie, Professor of Engineering for Sustainable Development at Cambridge University, was part of the research team.
"Waterwheels produce less energy than marine current turbines, but they are robust and require low maintenance," he said.
"We have been searching for a way to generate renewable energy on the river that would bring jobs and investment.
"But we must also respect the Mersey estuary's international importance for wildlife such as wading birds," he added.
Joe Flanagan, head of energy at the Northwest Regional Development Agency, said: "This study highlights how one of the Northwest's natural assets can be utilised for sustainable energy opportunities."