System analysis 2019 of German TSOs on demand for reserve generation capacity.

In 2011 the German government decided to shut down existing nuclear generation units successively until 2022 and to accelerate the deployment of electricity generation based on renewable energy sources (RES). Since then the RES target figures were repeatedly increased in accordance with the European energy policy objectives. As nuclear generation units were erected close to load centers in Southern Germany and wind power generation is mainly located in Northern Germany, a significant increase in North-South load flows during strong wind situations has been observed. This is amplified by changes in the power generation portfolio together with the political commitment to increase cross-border trading capacities beyond physical transmission capacities. Especially in high wind generation scenarios with additional transit flows through Germany, the maximum transmission grid capacities may be exceeded. The congestion in the transmission grid needs to be mitigated by TSO instructed generation redispatch. The paper covers the periods 2019/20 and 2022/23 and considers annual trends, as well as severe scenarios. It provides insights into the legal, regulatory and analytical background of this system analysis. Besides refining the process for determining the robust reserve generation portfolio, in 2019 the flowbased market coupling methodology was implemented to adequately consider the future market framework as defined by the EU clean energy package. The methodologies are outlined and the results of the market and grid analyses are presented. In conclusion, the paper illustrates the increasing challenges to maintain system security and the need for adequate transmission system reinforcement. [ABSTRACT FROM AUTHOR]