https://www.bbc.co.uk/news/uk-england-tyne-58772572
National Grid Ventures president Cordi O'Hara said it was a "remarkable feat of engineering".
She added: "We had to go through mountains, fjords and across the North Sea to make this happen."
"North Sea Link (NSL) is also a great example of two countries working together to maximise their renewable energy resources for mutual benefit."
National Grid said the €1.6bn (£1.37bn) joint venture with Norwegian power operator Statnett would help the UK reduce carbon emissions by 23 million tonnes by 2030.
It has four other power cables running to Belgium, France and the Netherlands and said 90% of energy imported in this way would be from zero carbon sources by 2030.
Hydropower in Norway and wind power in the UK are subject to weather conditions and fluctuations in demand.
Using NSL, renewable power can be exported from the UK when wind generation is high and electricity demand low, or be imported from Norway when demand is high and wind generation low.