The UK is set to back a vast new fleet of offshore wind projects in the North Sea alongside eight other European countries including Norway, Germany and the Netherlands.
The government says the deal will strengthen energy security by offering an escape from what it calls the "fossil fuel rollercoaster".
For the first time, some of the new wind farms will be linked to multiple countries through undersea cables known as interconnectors, which supporters say should lower prices across the region.
But it could prove controversial as wind farm operators would be able to shop around between countries to sell power to the highest bidder - potentially driving up electricity prices when supply is tight.
Energy Secretary Ed Miliband will sign a declaration on Monday at a meeting on the future of the North Sea in the German city of Hamburg, committing to complete the scheme by 2050.
