The proposed 150MW Portbury Dock Renewable Energy Plant would generate enough power for more than 200,000 homes by burning wood that would largely be brought to the plant by boat.
Eon chief executive Dr Paul Golby said: "This scheme would be one of the largest biomass power stations ever built in the UK and would make a considerable contribution to helping the Government meet its renewable energy targets.”
Eon has issued a scoping statement to North Somerset Council, the Department for Business, Enterprise and Regulatory Reform and other interested parties outlining the company's plans and hopes to submit a full application to BERR in the middle of next year.
If the project gets the green light, construction is expected to start in 2010, with the first power being produced in 2013. The station would be fully operation would be reached in 2014.
Portbury Dock is the third of Eon's biomass developments in the UK.
The company already operates Scotland's largest dedicated biomass power station at Steven's Croft near Lockerbie. It received permission for a 25MW biomass station in Sheffield earlier this year.