Real-world optimization of Vanadium Redox Flow and Lithium-Ion Hybrid Energy Storage with Thermal Coupling for Electrical and Thermal Self-Sufficiency

This study examines a real-life multi energy system (MES) setup for residential buildings housing 150 residents, equipped with 220 kWp of photovoltaics and 9 kW of wind power. The system includes a hybrid energy storage system (HESS) with a Vanadium redox flow battery (VFB) and a Lithium-Ion battery (LIB) for the electrical sector. The VFB is also fitted with an innovative thermal coupling module (TCM), enabling dual use as heat storage. The research applies a mixed-integer linear programming (MILP) method, using linear models to capture variable losses and auxiliary loads of the HESS. The optimization aims to enhance profitability, reduce operational losses, and mitigate asset aging. Tests show that MILP reduces losses by up to 50% over a day’s operation, primarily by strategically operating the HESS to avoid the high auxiliary load of the VFB. Additionally, the MILP schedules LIB charging to avoid prolonged high state-of-charge (SOC) periods, reducing calendric aging by up to 58%. These objectives are achieved while maintaining lower operational costs compared to rule-based operation.