European transmission system operators on Tuesday presented a joint framework for building a cross-border offshore energy system, aiming to align regional planning, cost sharing and financing as countries accelerate the rollout of offshore wind and supporting infrastructure.
The Offshore TSO Collaboration (OTC) said the approach could enable up to 1,000 terawatt hours of clean electricity to be generated and transported across northern European waters by 2050 — around 40% of the continent’s projected power demand.
The recommendations were unveiled at the North Sea Summit in Hamburg, with chief executives from TenneT Holding, Elia Group, Energinet, TenneT Germany, EirGrid, Statnett, NESO, Amprion, National Grid Ventures and RTE France outlining the proposed measures and next steps.
A central pillar of the plan is an integrated European offshore grid based on hybrid connections linking wind farms to multiple countries, rather than standalone national links. The OTC said early joint analysis points to lower overall costs, higher efficiency and a more resilient power system under a regional model.
“Europe’s energy future will not be created solely through national individual solutions, but through regional planning, fair cost sharing and flexible financing,” the collaboration said.
The group has produced a network map identifying potential cross-border projects in the North Sea, Irish Sea and Celtic Sea, while work is expanding to involve wind developers, infrastructure operators and the hydrogen sector.
The OTC said differences in ownership structures, regulatory frameworks and revenue models among national grid operators mean there is no single financing solution. Instead, it is developing models for multilateral cooperation and shared cost allocation to support investment decisions.
Under its proposal, costs would be allocated using a combined ex-ante and ex-post approach. National contributions would be agreed before construction based on jointly modelled scenarios, with adjustments made after commissioning to reflect the actual benefits realised in each country.
The collaboration said this structure would provide certainty for major infrastructure investments while retaining flexibility as projects come online.
Financing could draw on a mix of public loans, private capital, green bonds, guarantees, hybrid instruments and grants, the group added, stressing that long-term regulatory frameworks for cost sharing are critical to mobilising large-scale capital.
The OTC traces its origins to the 2022 Esbjerg summit, where governments agreed a shared vision for North Sea offshore energy. Transmission system operators subsequently formed the collaboration to translate political commitments into technical and operational solutions.
Founded in 2022, the Offshore TSO Collaboration brings together 50Hertz, Amprion, Creos, EirGrid Group, Elia, Energinet, NESO, National Grid, RTE, Statnett, TenneT Holding and TenneT Germany.
