Impact of a Regional- and Time-Dependent Minimum Remaining Available Margin on Market Coupling and Redispatch

In 2019, the legal basis for the design of flow-based capacity models was adapted by EU Regulation 2019/943 and a minimum remaining available margin (minRAM) of 70 % was introduced. Various studies have examined the influence of such constant minRAM specifications on market coupling and the associated costs, as well as on the transmission grid’s utilization. The studies concluded that the grid’s physics is poorly represented by a constant minRAM specification and that increasing utilization of the grid results. On the other hand, it has not yet been investigated whether a regional- or time-dependent minRAM specification better reflects the grid’s physics and thus can create a better compromise between cost-effective market coupling and increasing congestion management costs. The results of this paper show that a regional- and time-dependent approach can contribute to a reduction in overall system costs.