Energy storage for PV-driven air-conditioning for an off-grid resort - A case study

Abstract

The current paper presents a case study of a PV-driven air-conditioning system with battery and latent heat storage applied for an off-grid resort in Bintan (Indonesia). The lead-acid battery bank has a nominal energy storage capacity of 47 kWh and the ice storage can store up to 92 kWh latent heat. The entire energy system of the resort was equipped with a comprehensive real-time data acquisition system to measure different parameters such as solar irradiation, temperatures, flow rates and power consumptions. More than 100 parameters are transferred minutely and monitored remotely across country borders. A TRNSYS model has also been developed to simulate the case study system dynamically. To assure accurate simulation results, the chiller and the Thermal Energy Storage (TES) models were calibrated using measured data from the monitoring system. Initial simulation results show the usage of the energy storages. The battery is utilised as a buffer to run the chillers with least disruptions and the TES is used to shift the cold generated during daytime to cool bedrooms at nighttime. The later one can also serve as a short-term energy storage over a few rainy days. For future works, we propose a comparative study of chilled water, ice and battery storage to design an optimal energy storage system for the resort based on the insights provided by this case study.