Technical Integration of Virtual Power Plants enhanced by Energy Storages into German System Operation with regard to Following the Schedule in Intra-Day

The rising share of renewable energies presents major challenges in terms of ensuring electrical supply in Germany. Problems are caused by weather-dependent infeed of decentralized generation units. As a solution, different renewable energy sources are pooled in a Virtual Power Plant (VPP). In VPPs, these generation units are coordinated and scheduled in order to reduce deviations from forecasts and therefore allow operation as a conventional power plant. This paper evaluates the technical integration of VPPs into the German power system. The examined VPP is considered in a defined use case and consists of wind, photovoltaic and biomass generation units, enhanced by an energy storage. In order to coordinate systems, the operational concept of following the schedule in intra-day is focused. Therefore, a profit maximized schedule in day-ahead is developed which is to be followed in intra-day under economic aspects using mixed integer linear programming. In particular, benefits of system integration of energy storage in VPPs are presented. Results of case studies indicate a positive use of energy storage to reduce deviations from the schedule due to diverged weather forecasts, which has only small effects on VPP profit.