The first subsea electricity cable between Scotland and England could be operational by 2016 after the organisations behind the project agreed a £1billion contract.
National Grid and Scottish Power Transmission have awarded the deal to Siemens and cable-maker Prysmian, which will build the onshore connectors for the link between Hunterston and the Wirral.
The grid upgrade will allow up to six gigawatts of renewable energy produced in Scotland to be transported south of the border to help the UK meet green targets by 2020.
The 260-mile link will be the longest of its kind in the world. Scottish Power chairman Ignacio Galan said: “The additional capacity from this link will provide a significant boost to renewable-energy projects that we are developing in Scotland.”