The deal was secured by joint venture backers SSE Renewables and Equinor for the first two of three phases.
Onshore construction is currently underway for Dogger Bank A and Dogger Bank B, with offshore construction on Dogger Bank A due to begin in Q2 2022.
Dogger Bank A and B will each require total capital expenditure of around £3bn, including offshore transmission investment of around £830m per phase.
The project has already created hundreds of UK jobs, with more to come as project construction ramps up.
Once finished Dogger Bank will produce enough clean, renewable electricity to supply 5% of the UK’s demand, equivalent to powering six million UK homes.
The funding of the development of Dogger Bank A and B represents the largest ever offshore wind project financing anywhere in the world and SSE’s expected equity investment forms part of its £7.5bn investment programme to March 2025, the renewables element of which will double its renewables output by 2025.
Alistair Philips-Davies, SSE Chief Executive, said: “We are proud to be leading on the construction and development of Dogger Bank Wind Farm, which has been 10 years in the making.
“We are putting our money where our mouth is on delivering net zero and reinforcing the UK’s position as a world leader.
“This investment will help drive a green recovery from coronavirus through the project’s construction over the next five years, creating jobs and boosting the local economy.
“Achieving financial close for the first two phases of the world’s largest wind farm is a huge accomplishment and, alongside reaching Seagreen 1 financial close earlier this year, represents significant progress towards achieving our goal of trebling our renewable output by 2030.”