Charging and discharging a coaxial borehole heat exchanger as a battery

Abstract

We investigated the possibility of using deep coaxial borehole heat exchanger as a potential storage device of not only heat or coolness, but also an invaluable device that shifts the peak load of both heating and cooling for an electric system. We want to, therefore, investigate the potential of using CBHE as a battery. Using a bottom-up approach, we analyzed the existing literature and adapted the existing model with the sole emphasis on the thermal improvements of deeper borehole when considering the impact of geothermal gradient. This paper presents some preliminary analysis of how CBHE configuration can be used to maximize its performance as an energy storage option. Future work on improving the accuracy of the model, validate with data from an actual borehole as well as conducting multi-variate rigorous optimization could further improve the current study.