Norwegian energy company Statoil announced Crown Prince of Norway Haakon Magnus took part in a ceremony to open the Sheringham Shoal offshore wind farm.
Connected to the grid in August 2011, the wind farm boasts 88 turbines and can generate as much as 1.1 terawatt-hours of electricity per year.
Statoil, and its partner Statkraft, said the completion of the wind farm means the United Kingdom has more than 2.5 gigawatts of operational offshore wind capacity.
The completion comes three years after construction began. British Secretary of State for Energy and Climate Change Edward Davey, who took part in the ceremony, said renewable energy projects like Sheringham Shoal would provide regional economic stimulus.
"Today's opening is also an illustration of the strength of the U.K.'s strategic relationship with Norway," he said. "Investment in the U.K.'s energy mix needs to come from increasingly new and diverse sources, and this project is an excellent example of that."