Refrigerant-Based Energy Storage System
This project demonstrated the functionality of a refrigerant based energy storage (RBES) for air conditioning (A/C) system under different cooling load conditions. The RBES A/C system is designed to shift on-peak A/C demand to non-peak periods. It applies to buildings with a cooling capacity of up to 7.5 tons. The system can operate under two main configurations; stand-alone or hybrid. In the stand alone configuration, the system basically functions as a classical thermal energy storage (TES) system. It simply shifts a large portion of on-peak demand to mid- and off-peak periods. Under the hybrid configuration, the RBES A/C system is an add-on to the existing conventional A/C system of the building. The hybrid set up can be leveraged to address demand curtailment in response to an advance signal. Five RBES A/C systems were installed at three Southern California Edison sites. The findings from this project, under winter conditions indicate these units can mitigate the A/C electric demand by 6 kW in small commercial applications with 5 tons of cooling load.