Decentralized price-driven grid balancing via repurposed electric vehicle batteries

Based on one year simulations, a sequential quadratic programming (SQP) approach is compared to a dynamic programming (DP) and an integer linear programming (ILP) approach with respect to runtime and control objective. All approaches lead to very similar results, however ILP leads to the shortest runtimes. ILP is then used to investigate the grid balancing potential using last decade's hourly day-ahead prices. Higher market data resolutions featuring quarter-hours introduced in 2014 lead to higher earnings. For hourly day-ahead prices the optimal capacity-to-power ratio of the battery is approximately 6 h while for quarter-hourly prices it is about 3 h.