Offshore wind power: getting the electricity from the sea to the mountains

Federal Ministry of Economics and Technology: striking the balance between vision and pragmatism

The rough seas are a challenge both to humans and to materials, and are not easy to tame into providing a reliable power supply. Winds are roughly twice as strong at sea as when used on land.The challenge is to anchor the use of wind energy in an overall strategy for modernised energy systems and power grids.

The logistics of installing wind energy facilities and connecting them up to the grid are easier to handle on land than at sea.After all, once beyond the coastline, it is necessary for specialists to undertake the difficult task of laying underwater cables before the electricity can make its way to land. But even once the electricity has landed, much work remains to be done.We simply move on to the next challenge of transporting the power to the centres of consumption.

According to the 2005 grid study produced by the German Energy Agency (dena), an additional 850 km of new high-voltage power lines need to be built and 400 km need upgrading in order to transport the wind power to the households, even in remote regions. But improving the grid is just one aspect: in future, it will also be important to network residential customers and large industrial consumers, urban and rural areas with differing power generation capacities in an intelligent manner.

Experts believe that new wind farms with an installed capacity of between 20 and 25 gigawatts (GW) will need to be built in the North Sea and the Baltic over the coming 20 years. If the related technological challenges are to be mastered, we will need close co-operation on research at both national and international level.