TenneT, the Dutch/German offshore transmission system operator (TSO), has initiated a tender in Germany for feasibility studies aimed at developing an innovative offshore subsea transformer concept. This concept, known as the TenneT Offshore Subsea Transformer, aims to accelerate the expansion of offshore grids by simplifying and downsizing traditional offshore converter platforms, thereby potentially reducing costs.
The proposed approach involves relocating critical components of offshore grid connection systems to the seabed. By doing so, TenneT aims to complement the new 2 GW standard in offshore wind grid connections, facilitating quicker deployment of offshore wind energy projects.
The tender, launched on 27 June, is structured into four lots focusing on feasibility aspects of various system components: VSC-HVDC transformer, EHV submarine cable, reversible EHV subsea connector, and installation concepts. Interested parties have until 19 July to submit their requests to participate.
While specific details of the subsea transformer concept have not been disclosed, the initiative underscores ongoing industry efforts to innovate and optimize offshore grid connectivity. Earlier this year, Aker Solutions and the Marine Energy Test Centre in Norway announced progress on their own subsea grid connection platform, aimed at enhancing efficiency and reducing infrastructure costs.
Known as the Subsea Collector, Aker Solutions' concept proposes a star configuration to connect multiple floating wind turbines, potentially reducing offshore transmission infrastructure costs by up to 10 percent.