Establishing offshore grids in the North Sea

Project state
Offshore wind farms generate considerable energy. However, this still has to be transported to the coast and distributed across the country.

This project is aimed at analysing and assessing different market and grid connection variants for offshore electricity grids in terms of how the variants impact on the German energy supply system and the superordinate European interconnected power system.

With the help of energy industry simulations, innovative mathematical optimisation models and methods as well as analyses of the European interconnected power system, the project participants are investigating the feasibility and energy industry implications of different offshore grid concepts.

The aspects taken into account include connecting synchronous/market areas, planning and operating meshed multi-terminal HVDC grids for different applications, incorporating existing storage capacities in Norway and the UK as well as integrating new offshore storage concepts for providing balancing and flexibility options for secure grid operation.

Determination of the storage requirement and the greater flexibility of the overall system

The engineers are establishing the general advantages and disadvantages of different grid connection and market concepts for North Sea Offshore Networks (NSONs) for individual countries and for the region as a whole. As part of the results, they want to identify the costs and potential for reducing greenhouse gases created by the electricity generation and consumption. In addition, they also want to determine the necessary transmission capacities and grid utilisation, as well as the potential for reducing the need for additional storage capacities for such NSONs in all participating countries. The additional connection capacities provided by the NSONs give the overall system more flexibility, which will also be evaluated as part of the results. As methodological components, the newly developed mathematical optimisation techniques also provide an important and easily reusable instrument for solving highly complex planning problems in the construction and operation of future energy transmission grids.

In addition, using load flow calculations, the German transmission grid will be analysed in terms of the impacts caused by the integration of an offshore grid and possible limit breaches in the grid operation. The methods being developed in the project provide the database for investigations usable beyond the project on congestion management and the elimination of voltage range breaches in the transmission grids. This makes it possible to identify the investments needed in the national transmission infrastructure and grid expansion requirements.

Project duration

10/2014 - 09/2017


Dr.-Ing. Stefan Bofinger
Project coordinator
Fraunhofer Institute for Wind Energy and Energy System Technology (IWES)
Königstor 59
34119 Kassel
+49 561 7294-371

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