Investigation on the Use of Phase Change Materials in Geothermal Energy Applications

Geothermal energy (GE) is one of the most stable renewable energy sources. Phase change materials (PCM) can be integrated with geothermal systems to avoid thermal imbalance at high loads. It can be used mainly as grouting or thermal storage material. This article presents a review of the utilizations of GE with PCM and highlights the corresponding advantages. PCM can stabilize the performance of the GE system while decreasing its operating cost. The most favorable configuration of the PCM based GE system is the underground thermal battery in which the PCM and water are coupled to enhance the heat transfer rate.