Report by Rachel Bullock
Britons will soon see their homes powered up by Norwegian fjords connected by the world's longest subsea power cable.
The UK and the Scandinavian nation have joined forces to share renewable energy sources via a 450-mile "interconnector" hailed as a "remarkable feat of engineering".
More than one million British households will be heated and lit up by water flowing from Norwegian mountains to fjords as the two nations connect their power grids.
The National Grid said connecting Northumberland to western Norway will dramatically help reduce the burning of fossil fuels for power across the UK.
How will this work?
The €1.6 billion (£1.4 billion) North Sea Link is a joint venture between National Grid and Norwegian system operator Statnett which has already started commercial operations.
The 6 inch-wide cables will connect Cambois, in Northumberland, with the Norwegian village of Kvilldal, in western Norway.
It will start by running with a maximum capacity of 700 megawatts (MW) and will gradually increase to the link’s full capacity of 1,400 MW over a three-month period.
When it is at full capacity, it will provide enough clean electricity to power 1.4 million homes, National Grid said.
Where will the energy be sourced from and how will it be shared?
Water flowing from Norwegian mountains to fjords is harnessed by hydropower stations and connected to the UK.
The cable will also allow excess wind power from Britain, when turbines are producing high levels of electricity in windy conditions but demand is low, to be exported to Norway to power homes there.
This will mean the Norwegian grid can effectively store energy by conserving water in the country’s vast Blasjo reservoir - which is used to feed hydropower plants - for use at another time.
At Kvilldal, on the edge of a peaceful lake, a converter station has been built to enable the cheap electricity generated by a hydropower plant, deep inside the Norwegian hillside, to be transmitted to the UK.
Cables from the converter station, which is linked up to the Norwegian grid next to the hydropower plant, have been laid through the lake and a tunnel to blast through the hill to the nearby fjord and then out to the North Sea.
Sub-sea cables then carry the renewable power to another converter station at Blyth where it enters the British grid.
Cordi O’Hara, president of National Grid Ventures, said the North Sea Link was “a truly remarkable feat of engineering”.
“We had to go through mountains, fjords and across the North Sea to make this happen," she added.
How will this impact the environment?
National Grid said the North Sea Link would help avoid 23 million tonnes of carbon emissions by 2030.
The scheme, which took six years, is the fifth interconnector for National Grid, which also operates links to Belgium, France and the Netherlands.
By 2030, 90% of the power imported via the interconnectors will be from zero carbon sources, said the company.
UK Energy, Clean Growth and Climate Change Minister Greg Hands said: “As we prepare to host the UN Cop26 summit, this pioneering partnership shows first-hand how crucial international cooperation will be in helping us to deliver on our net zero ambitions and provide clean renewable energy to millions of UK homes.”
Ms O'Hara added: “As we look forward to Cop26, North Sea Link is also a great example of two countries working together to maximise their renewable energy resources for mutual benefit.”