According to DNV GL, the certification guarantees the project is safe and efficient.
DNV GL said the size of the project, and its distance from shore, created several challenges. There were also "no comparable" projects from which to draw experience.
The group provided personel to help install the project's monopile foundations and transition pieces. It also aided the installation the project's electrical system.
As a result of the collaboration, previously held limits were pushed. DNV GL found that concrete for the transition pieces could be installed at temperatures lower than five degrees Celsius, in higher wind speeds and in stronger waves. This reduced the amount of time needed for construction, DNV GL said.
Meerwind Sud/Ost was fully completed in March this year. It has 80 Siemens 3.6MW turbines installed 23 kilometres off the German coast.
It is connected to the German grid via the HelWin1 platform, also manufactured by Siemens.