Combining frequency containment reserves and renewable power leveling in energy storage systems

The objective of this paper was to show that a combination of renewable energy sources with energy storage systems, which provide frequency containment reserves FCR (also called primary frequency control), improves the performance of both systems. This double benefit comes out in a reduction of intraday trading for the storage system and a leveled power injection of the renewables. Considering the regulations that apply for battery storage systems to provide FCR in Germany, interaction with other units is essential to guarantee availability of the system. This interaction is usually performed market based by intraday trading or by flexible power generation or consumption combined with the storage system. This paper, however, showed the benefits of interaction with fluctuating renewable energy sources. Energy storages and renewables were clustered to a common grid connection point to utilize the fluctuations of the renewable power generation directly for battery management. Simulation results based on sample photovoltaic and wind profiles showed the double benefit of the configuration. Intraday trading was reduced by 33% up to 57%. At the same time, fluctuations decreased, so the renewable power injection better matched a predefined power schedule. (C) 2016 The Authors. Published by Elsevier Ltd.