Battery Capacity Reduction for Stand Alone PV Air Conditioner by Using Curtailed Electricity to Store Chilled Water as a Backup

Due to good matching between solar irradiation and cooling demand both in time and quantity, trying to make PV air conditioner independent from public grid so as to develop a stand-alone PV air conditioner is always a struggling objective for researchers and engineers. However, limited by the high cost of battery, it is a hard task to popularize stand-alone PV air conditioner among broader areas. In this paper, a strategy, which converts curtailed electricity of PV system into cooling storage as a backup for cooling demand, to reduce battery capacity for stand-alone PV air conditioner is proposed. To investigate the effect of this strategy, a stand-alone PV air conditioner with both battery and chilled water tank is built in TRNSYS. A fictive office building in Haikou is chosen to do case study. Through sizing work, the results show a reduction for battery capacity, which supports the application of this strategy.