Due to the massive expansion of wind power in Northern Germany and the building of new conventional power plants close to the sea in forthcoming years more and more electricity has to be transmitted from the north to the south. Adding to the problem, with electricity market liberalisation in Europe cross-border power trading is increasing as well. Thus, experts agree that the expansion of Germany’s transmission system is overdue. The German Energy Agency (dena) estimates that some 850 kilometres of extra high voltage lines (220 and 380 kilovolt) will have to be built in the forthcoming years – about 2,4 per cent of the overall transmission grid.