The price of electricity generated by wind turbines, both on and offshore, has fallen to make it competitve with plants that use fossil fuels

Norway's Equinor and Britain's SSE Renewables have been selected to build the world's largest offshore wind farm off the British coast, an investment of 10.2 billion euros ($11.3 billion), Equinor said on Friday.

The two energy groups were awarded contracts to develop three large scale projects in the North Sea's Dogger Bank area with a capacity of 3.6 GW, expected to produce enough energy to power the equivalent of 4.5 million British homes, Equinor said.

The wind farm will consist of three projects, Creyke Beck A, Creyke Beck B and Teesside A, each with a capacity of 1.2 GW.

The total 10.2-billion-euro investment will run from 2020 to 2026.

However, a final investment decision for the first is expected during 2020, and first power generation is planned for 2023.

The clearing price is around 45 euros per megawatt-hour.

"What's now abundantly clear is that the more offshore wind we build, the cheaper our bills will become," said John Sauven, the head of Greenpeace UK, calling on the British government to "raise their ambition levels to tackle the climate emergency."

SSE, a Scottish group listed in London, will be responsible for the construction of the farm and Equinor will be the operator.