Earlier this month, the installation of 54 turbines began on the project, while seven turbines have been already installed.
According to the company, turbine installation will continue in parallel with the progressive commissioning of the wind turbines.
Last year, all 54 foundation monopiles and transition pieces, in addition to other offshore substation and infield cables, have been installed at the project.
The installation and commissioning of all 54 Nordsee One turbines are expected to complete by the end of this year, said the company.
Once commissioned, the 332MW wind facility is expected to generate around 1,300GW electricity, providing power to around 400,000 German households.
Northland is the majority stakeholder with 85% interest in Nordsee One, while Innogy owns the remaining 15% interest.
Northland CEO John Brace said: "We're pleased to report that this important milestone has been achieved on time. Our capable and diligent project team will continue to work closely with our contractors to enable a successful installation and connection process from start to finish."
Last September, Siem Offshore Contractors completed installation of all 70km of inter array grid cables on the Nordsee One offshore wind farm.
The CLV Siem Aimery loaded in excess of 70km of aluminium core submarine composite cables directly into its two turntables in addition to cable protection systems, which were loaded into a dedicated under-deck storage compartment.
