Levelised Cost of Thermal Energy Storage and Battery Storage to Store Solar PV Energy for Cooling Purpose
Abstract
In this paper, we define scenarios for cooling applications that are coupled with photovoltaic (PV) systems and highlight the role of energy storage. Subsequently, we develop the method of Levelised Cost of Storage (LCOS), which has been developed for electricity storage in the literature, further to compare thermal energy storage and battery storage for cooling application coupled with PV systems. Lastly, we apply the method to a real scenario and determine the LCOS of thermal energy storage and battery storage configurations. The existing 11,000 m² office-cum-retail in the tropics of Singapore utilizes a 1055 kWth chiller to supply its air-conditioning needs. Moreover, the rooftop is capable to accommodate a 247.5 kWp PV system. A parametric simulation study was considered by varying the usable energy storage capacity from 100 kWh to 5000 kWh. It was found that for battery storage 300 kWh capacity offers the lowest LCOS of 0.10 USD/kWh for this particular application. However, the LCOS of the chilled water storage is at 0.06 to 0.08 USD/kWh for various storage sizes. Nevertheless, the battery storage is able to increase the self-consumption of PV energy more than the thermal energy storage option, as the chiller plant control proved to be crucial for the integration of thermal energy storage.