Sizing and techno-economic assessment of battery energy storage systems for renewable energy curtailment mitigation in islanded power systems: Application to Cyprus

Battery Energy Storage Systems (BESS) can be deployed as a flexibility resource to mitigate Renewable Energy Curtailment (REC) and improve system efficiency in power systems with high Photovoltaic penetration. This study focuses on the sizing, operation, and techno-economic performance of BESS under high REC conditions, using the islanded power system of Cyprus as an application case. Based on official REC data for the period 2022–2025, the environmental and financial implications of REC are quantified and used as inputs to a BESS-centred operational simulation framework. The analysis evaluates BESS performance under different storage durations, examining the ability of battery energy storage to utilised REC, manage peak demand, and extend energy utilisation over time. The results indicate that increasing BESS duration enhances REC exploitation up to a saturation point, beyond which additional energy capacity yields limited marginal benefits. A techno-economic assessment of BESS operation under REC conditions further shows that, despite positive operational and environmental outcomes, additional support mechanisms are required to improve investment attractiveness. Overall, the findings provide storage-focused insights relevant to policymakers, network operators, and investors, for the effective sizing and deployment of BESS in curtailment-constrained power systems.