Energy regulator Ofgem has approved a £3.4 billion electricity “superhighway” between Scotland and England in the biggest single investment for electricity transmission infrastructure in Britain.

The 500km (311-mile) Eastern Green Link 2 (EGL2) project will stretch from Aberdeenshire to North Yorkshire and will transport vast amounts of renewable energy between Scotland and England.

The joint venture between Scottish and Southern Electricity Networks and National Grid is part of a push to modernise the electricity grid to deal with greater demands placed on it by the green transition.

The new network capacity from the power line will carry enough renewable electricity to power two million homes, Ofgem said, describing it as a “superhighway”.

Ofgem is fully committed to supporting the Government to meet its aims of getting clean power by 2030. Today’s announcement is a further step in putting the regulatory systems and processes in place to speed up network regulation to achieve its aim

Chief executive Jonathan Brearley said: “Ofgem is fully committed to supporting the Government to meet its aims of getting clean power by 2030.

“Today’s announcement is a further step in putting the regulatory systems and processes in place to speed up network regulation to achieve its aim.”

The massive new interconnector cable will be able to move two gigawatts of electricity between Scotland and England, partly enabling the latter to benefit from offshore wind energy generated by offshore wind farms in the North Sea.

Ofgem said it is pushing to fast-track the approvals process for power projects to help the UK meet its 2030 net zero carbon emissions target.

The announcement also comes after Labour said it would ease planning regulations, as part of a bid to get more homes and power infrastructure-related schemes built in the coming years.

Most of the 500km (311-mile) cable will be laid under the North Sea, while the rest will be underground onshore, Ofgem said.

Construction is planned to start later this year, with the new connection due to be operational by 2029.

Lawrence Slade, chief executive of trade group the Energy Networks Association, said: “This is really welcome news from Ofgem. To move us forward towards clean power will require the biggest upgrade to the grid in decades.

“In turn these projects will unlock jobs, secure work for contractors and suppliers, and ultimately mean more secure energy supplies in the future. This is a crucial part of that jigsaw.”

The regulator also provisionally gave the green light to a £295 million funding package for a set of upgrades to the electricity grid in Yorkshire.

The project, which is run by National Grid, will involve building new substations and overhead lines to improve networks in the North East of England.

Separately, the Electricity System Operator has unveiled plans to connect up to 4.5 gigawatts of floating offshore wind power from the Celtic Sea to south Wales’ and south-west England’s grids.

The plan is part of the ESO’s own push to upgrade the UK’s renewable energy capacity, and could provide enough power for more than four million homes.

The design includes three connections from offshore wind farms, two for south Wales and one for south-west England.

The ESO moves electricity around the system to keep homes and businesses supplied with the energy they need 24/7. It is part of National Grid, but is set to be spun off into a separate entity this summer.

The plans come before auctions for the so-called Contracts for Difference (CfD) scheme later this summer, which sees developers bid to secure a fixed price they can charge for each megawatt hour (MWh) of renewable power they generate.

Last month, the Government said it has increased the budget for the next wave of schemes to a record £1.5 billion.

ESO’s chief engineer Julian Leslie said: “Offshore wind is vital to achieving the Government’s target for clean power by 2030, sustaining energy security and achieving net zero by 2050, so it is a really positive development that this is the first time an offshore wind leasing round will have been launched with a recommended high level network design in place.”