Performance prediction of a vanadium redox battery for use in portable, scalable microgrids

Summary form only given. Vanadium redox batteries (VRBs) have proven to be a viable energy storage technology for portable microgrids due to their rechargeability and high energy density. Pumping electrolyte across the membrane during charging and discharging cycles of the VRB leads to a parasitic load loss. To ensure the electrical equipment is not exposed to extreme ambient temperatures, VRBs must also have temperature control in the form of heating, ventilation and air conditioning, which also result in parasitic load loss. This paper focuses on empirically characterizing VRB efficiency based on known climatic operating conditions and load requirements. A model is created to determine system performance based on known climatic and load data collected and analyzed over an extended time period. A case study is performed using known data collected over a weeklong time period to characterize system performance, which was compared to actual system performance observed during this same time period. This model effectively predicts peak available ac/dc load as well as VRB efficiencies based on climatic field measurements and VRB state of charge (SOC) and estimates appropriate sizing of the PV array and discretionary loads based on required energy density of the system.