Hybridisation of battery/flywheel energy storage system to improve ageing oflead-acid batteries in PV-powered applications

In this paper, the complementary characteristic of battery and flywheel in a PV/battery/flywheel hybrid energy storage system is explored for a solar PV-powered application. The impact of hybridising flywheel storage technologies with battery on the ageing of battery and its economic effectiveness when used with a PV system is presented. The ageing of a lead acid battery is modelled using Schiffer weighted Ah-throughput model while the economic analysis is modelled using total cost of ownership approach. Two scenarios (i.e. PV/Battery and PV/Battery/flywheel) are created to appreciate the complementary characteristics of a hybrid storage system in a PV-powered application. Sensitivity analysis was also carried out to understand the effect of a change in degradation and corrosion limit as well as charging and discharging current on the ageing of a lead acid battery. Some of the key results reveal that a hybrid of Battery/Flywheel presents a lower capital and total cost of ownership compared to battery only when used in a PV powered-combined fishery and poultry farm. The results also show that the life of a lead acid battery can be extended when combined with a flywheel compared to a battery only storage system.