DNV GL and TenneT have signed a four-year framework agreement covering project certification of new high-voltage direct current (HVDC) substations in the German North Sea.
The agreement includes the certification of the planned DolWin5 converter platform which features a grid connection concept for wind farms that could reduce costs for the offshore wind industry. The platform features a connection concept to link for example the “Borkum Riffgrund West I and II” and “Northern Energy OWP West” wind farms to an offshore HVDC converter next to the wind farms. The DolWin5 concept connects the wind turbines directly to the offshore platform via 66 kV cables. This removes the need for separate substations for each wind farm and the 155 kV cables previously used to connect the wind farm substation to the converter platform leading to cost savings. The platform is planned to start operations in 2024. Project certification will be performed according to the BSH Standard Design, in order to verify compliance with requirements of the German Federal Maritime and Hydrographic Agency (BSH).