Multiterminal hubs: A large step to the energy grid of the future

7a1 - Multiterminal hubs: A large step to the energy grid of the future

TrackRPG & Future Power Systems 1

Dennis Stemme, Lead Program DC Engineering, Construction Commissioning, TenneT TSO GmbH, Germany

Germany is embarking on an ambitious project to realise a climate-neutral grid: the development of multiterminal hubs, the first of their kind in Europe. To implement this unique technology, the four transmission system operators – 50Hertz, Amprion, TenneT and TransnetBW – and industry leaders Hitachi Energy, Siemens Energy and GE Vernova are joining forces in an innovation partnership. The project aims to create a DC grid that will significantly increase the flexibility of the system at all levels. Multiterminal hubs will connect the high-voltage direct current (HVDC) lines (onshore and offshore), creating an interconnected HVDC network instead of pure point-to-point connections. This will contribute to Germany's ambitious goal of integrating 70 GW of offshore wind power from the German North Sea into the grid by 2045. 

The objectives of the innovation partnership are clear. It will facilitate the efficient integration of offshore wind energy into the existing grid infrastructure and optimise energy distribution across Germany. The initiative also aims to minimise the use of land for new installations while keeping costs stable for consumers. Finally, it contributes to Europe's broader energy future by developing innovative solutions that meet sustainability goals and enhance the interoperability of HVDC grids. 

The first three multiterminal hubs consist of a DC switching station with a newly developed 525 kV DC circuit breaker, a converter and a substation – so far each of them from a single vendor.  

A key aspect of the hub technology is the development of DC circuit breakers as part of the DC switching station. These breakers can detect faults in fractions of a second and isolate the affected areas, ensuring safe and reliable operation of the system. The DC multiterminal systems will operate at a voltage of +/- 525 kV and use a bipolar configuration with a metal return, allowing a capacity of 2 GW per converter station. 

The project will be implemented in three successive phases over a period of approximately ten years. The first phase, focusing on research and development from 2024 to 2025, will develop specific hub component concepts, ensuring a compatibility between the different systems. This will be followed by a pre-qualification phase from 2026 to 2027, during which industry partners will demonstrate their expertise and capabilities in implementing multiterminal hub technology and make the DCCBs market ready. The final phase, implementation, is planned for 2028 to 2033 and will involve the construction of three pioneering hubs: HeideHub by 2030, NordWestHub by 2031 and NordHub by 2033. 

By fostering collaboration between key stakeholders, the project aims to address future energy challenges while supporting a sustainable energy landscape. The development of multiterminal hubs is expected to strengthen the resilience of the entire European grid, increasing security of supply, flexibility and stability. 

Dennis Stemme, Lead Program DC Engineering, Construction Commissioning, TenneT TSO GmbH, Germany

In this session

Multiterminal hubs: A large step to the energy grid of the future

Dennis Stemme

TenneT TSO GmbH, Germany