Techno-economic sizing of a battery energy storage coupled to a wind farm: An Italian case study

The study focuses on the technical and economic issues which arise when a battery energy storage is coupled to a wind farm to improve its profitability. The electric energy storage technologies may fulfil the dual role of promoting the renewable energy sources development and of allowing an economic optimization of the energy output. In this study, the optimal economic and technical sizing of a lithium-ion battery, is analyzed by focusing on the day-ahead market profit maximization. This is done by scheduling the aleatory wind production using a 24-hours rolling horizon MILP optimization algorithm. The annual utilization profile and daily charge level are analyzed, and the related battery degradation is assessed. Finally, the battery cost is compared to the additional revenues, to assess the battery cost-optimal size in presence of battery degradation. The analysis is based on real Italian wind data and energy price time series.