„Interaction between Redispatch and Transmission Network Expansion Planning in Germany – An Electricity Market Model based Study“
The energy transition in Germany is in full swing and paves the way for a more sustainable energy future. It requires both an expansion and a reshaping of the current transmission network to specifically accommodate the integration of renewab-le energy sources. Even though grid reinforcement and expansion are already on the way, delays and a slow planning process lead to a continuous need for congestion management. Especially redispatch volumes have been increasing over the last few years and total congestion management costs have more than tripled between 2014 and 2017 by 1.5 bn EUR.
The quantitative analysis of this thesis provides insights of the potential of redispatch as a cost-optimal alternative to grid expansion as well as the development of future conges-tion management measures in Germany. An integrated model of redispatch and grid expansion is formulated using high spatial reso-lution techno-economy electricity market model ELMOD. The applied methodology is based on linking the theoretical background of congestion management methods in Germany with the current state of the modelling theory on solving the transmission expansion plan-ning and redispatch problem. The model formulation contributes to the scarce literature on modelling both redispatch and grid expansion and represents one of the first formulations in such a large scale model.
The results of the thesis indicate that congestion management mea-sures can contribute to cost-efficiency and replace specific AC transmission lines planned for investment in Germany. Nonethel-ess, grid expansion, especially in HVDC transmission lines is highly needed to enable the integration of volatile renewable resources in Germany. Despite grid expansion efforts, short-term congestion management seems to remain an important measure for network security in the future. It can be assumed that especially after 2035, with no further grid expansion planned so far, congestion ma-nagement will play an important role in avoiding further grid expan-sion needs.