BNetzA – Report to determine the necessary network development in the German transmission system

Originally, the German electricity sector was primarily based on a system with large-scale power plants close to consumption and their mutual backup. This system is increasingly being replaced by a system in which generating is volatile in time, supply-dependent, and where power plants are remote from load centres. Along with this development, the network side transforms from an interconnected European grid system into a European transmission system, i.e. a network with directed power transmission and new functional system elements. As part of the report, the following questions in particular were addressed to the Graz University of Technology:

• Vulnerability analysis and specification of requirements for the transmission network for three predefined scenarios, each of them with eight grid usage cases
• Analysis on the impact and benefit of controllable system elements on the electricity system
• Determining grid expansion requirements taking into account the (n-1) reliability for the reference case 380-kV three-phase supply expansion
• Determining grid expansion requirements taking into account the (n-1) reliability for different versions of transport corridors
• Available transmission technologies

As requested by the Federal Network Agency, the grid expansion requirement was determined based on the network development plan of the transmission system operators and by taking the (n-1) reliability into account, for two special cases of transport corridors.