Utilisation of energy storage to improve distributed generation connections and network operation on Shetland Islands

The Northern Isles New Energy Solutions (NINES) project on the Shetland Islands seeks to trial the application of alternative solutions, including demand side management and battery energy storage to increase the integration of renewable generation and smooth the demand curve. As part of the NINES project, a 1MW, 3MWh Battery Energy Storage System (BESS) has been installed in the Shetland network and initially operated by an Active Network Management (ANM) system and then brought under the manual scheduling. The main objective was to reduce peak demands to be met by conventional generation and also to increase the demand at off-peak times which may provide additional headroom for non-firm distributed generation, i.e. ANM Controlled Generation (ACG). This paper aims to present experiences and findings from the NINES project regarding the BESS’s operation, utilisation and efficiency (energy losses). Furthermore, the constraint rules that limit the ACG export are discussed alongside practical issues around charging the BESS in response to the ACG curtailment.