The development in electricity exchanges and their impact on the German transmission system

In Germany large parts of the 110 kV, 220 kV and 380 kV systems were erected between 1960 and 1975. The system was designed with the aim of reducing transmission losses and distances to a minimum. So the power plants were built close to areas with a large consumption. Especially since the liberalization of the energy market in the late 1990s the Transmission System Operators (TSO) have been facing new challenges. The amount of energy exchanged between countries in Europe is growing. In this paper not only the developments of the exchanges are presented but also their impact on the German power system. This paper will show that a useful method to measure the system performance and reliability has to be found. Two different possibilities will be compared - the reliability analysis with its much used value of not delivered energy W and a new method calculating the importance of each line regarding its topology and other factors.