The 1,218MW Hornsea Project One wind farm has reached the halfway turbine installation point, Ørsted said.
87 out of the wind farm's 174 Siemens Gamesa wind turbines have now been installed and commissioned at the site some 120 kilometres off Yorkshire.
The wind turbines are being transported from Hull and installed by Fred. Olsen Windcarrier's jack-up vessel Bold Tern and A2SEA's Sea Challenger.
With 87 more turbines due to be commissioned, the site is due to reach full completion in the first quarter of 2020.
The power generated by the wind turbines is converted from medium voltage to high voltage via three 400MW offshore substations. The electricity is then transmitted via the world’s first offshore Reactive Compensation Station, which is around half way between the site and the shore.