Impact of Uncertainties on Grid Congestion Management Measures with Long Lead Time

The expansion of renewable power generation, the increasing integration of European electricity markets, and the delays in grid expansion result in a high number of congestions in the European transmission grid. As a result, congestion management measures are increasingly planned under uncertainty, which poses challenges for the transmission system operators. In particular, the start-up decisions of power plants with a long lead time are made under great uncertainty. In today’s operational practice, transmission system operators often account for uncertainties and the worst case by adding safety margins to the results of deterministic redispatch simulations based on forecast data sets. This paper investigates the influence of different approaches to consider uncertainties implicitly in redispatch simulations, in order to gain knowledge about the impact of uncertainties in operational processes of transmission system operators. The exemplary results by means of grid reserve power plants show that additional safety margins to a deterministic approach to account for the worst case vary significantly depending on the situation. The probabilistic approach allows a more accurate estimation of the worst case, since it considers the influence of uncertainties on the start-up decision implicitly in the simulation. Finally, the comparison of these results with the stochastic approach shows that the worst case in the probabilistic approach can even underestimate or overestimate the impact of uncertainties and the stochastic approach prevents this.