Energy storage for enhanced frequency response services

In the last 7 years, the UK has seen an unexpectedly large increase in embedded power electronic connected generation connecting to both the transmission and distribution network. This is problematic to system inertia, since there is no inherent rotational mass within Power electronic connected generation to provide kinetic energy to the grid as required. National Grid must secure the system to protect the frequency against a single in-feed loss. However, as the system becomes less synchronous, it becomes less secure. As a solution to this, energy storage systems are being investigated as a possible option to assist with frequency regulation. National Grid are looking to trial a new Enhanced Frequency Response (EFR) service starting before or during 2018. This paper considers different Energy Storage strategies for assisting with frequency response and compares these to the EFR and the more traditional Fast Frequency response service.