The UK and Norway have signed an agreement to build the world’s longest interconnector.

The 730-kilometre power cable, which will link the two nations’ electricity markets directly, has a planned capacity of 1.4GW – enough to power nearly 750,000 UK homes.

UK’s National Grid and Norwegian transmission system operator Statnett reached a final agreement today.

The €2 billion (£1.5bn) project, expected to be completed by 2021, will run from Blyth in Northumberland to Kvilldal in Rogaland on the Norwegian side.

Energy Secretary Ed Davey said: “Britain will benefit from Norwegian green hydropower at the flick of a switch, providing green backup power when the wind’s not blowing and this will actually save people money.

“Coming after the recent confirmation of the Nemo interconnector project with Belgium, I am proud we are now seeing a huge increase in Britain’s energy options and the prospect of a real single energy market and energy supergrid in Europe.”

Earlier this month energy regulator Ofgem launched a consultation on its proposals to approve three new electricity interconnectors linking the UK with France and Denmark but rejected the one linking the nation with Ireland.

• interconnector, Norway, UK