A substancial amount of wind power, 30-60 GW, is foreseen in the northern part of the North Sea. These wind farms have to be connected to the national grids of five different countries in a flexible and economical way. Individual connection is straightforward but for several reasons possibly not the best choice. A high capacity North Sea Transnational Grid connecting wind farms to the national grids and at the same time connecting the national grids may well be a better solution for reasons of energy efficiency, availability, controllability, lower costs and the possibility to trade/exchange electricity.

Problems with individual connection of wind farms are the cable spaghetti they cause, low controllability, availability concerns and the number of crossing of the shore region. Problems with building and operating a North Sea Transnational Grid are modularity (building sections of the grid as soon as these are required), flexibility (combining different technologies, when these become available) and controllability. A large amount of wind power can potentially cause congestion and stability problems in national grids.

The objective of the North Sea Transnational Grid project is to determine the best solution (modular, flexible, most cost effective) for a high capacity transnational offshore grid, connecting all future wind farms in the northern part of the North Sea to the Netherlands, UK, Norway, Denmark and Germany. Different technical solutions for a Transnational Grid will be investigated. For the most promising solution a multi-terminal HVDC system control will be developed and tested and the Transnational Grid will be optimized. A second objective is to determine the effects of the Transnational Grid on the national grids: the operating strategy of the Transnational Grid will be developed to regulate power exchange correctly and avoid congestion and the effect of the Transnational Grid on national grid stability will be investigated. The costs, benefits, policies and regulations related to realisation of the North Sea Transnational Grid will be investigated and compared to alternative scenarios.

North Sea Wind Farm Locations and Transnational Grid investigated in NSTG (Photo: NASA)