A techno-economic analysis of a hybrid energy storage system for EV off-grid charging

This paper presents the techno-economic advantages of a DC coupled li-ion and lead-acid hybrid energy storage systems used for EV off-grid charging using visitors arriving at Marwell Zoo car park as a case study. The analysis shows that the hybrid storage systems can reduce the overall system costs by using li-ion batteries for frequent cycling linked with lead-acid for longer, less aggressive cycles. On-site overgeneration of 600 % of the total load gives the lowest total system cost. For the optimized overgeneration, hybrid storage system can further reduce the cost of the EV off grid charging system by up to 10 % when compared with a li-ion only energy store.