Reactive Power Retrieval at the TSO-DSO Interface in Germany: Identifying Approaches and Challenges

The decommissioning of conventional power plants in Germany leads to the reduction of reliable reactive power sources available in the transmission grid. The rising grid volatility and voltage sensitivity make it more difficult to predict critical voltage-related congestions and events. The use of the reactive power provided by renewable energy plants at the distribution grid level is proving to be promising for the congestion management of transmission system operators. The paper presents a testbed to evaluate, if procedures and regulations from existing congestion management instrument such as the German Redispatch 2.0 Process is suitable for reactive power. While previous research in the literature has been methodologically focused, the emphasis of this paper is on the presentation of the entire process in the testbed, to investigate the methodological and processual challenges during the retrieval at the TSO-DSO interface in C2RT. For this, relevant case studies are defined.