Developmental status and challenges of GWHP and ATES in China

Ground source heat pump (GSHP) facilitates the efficient utilization of renewable energy sources and energy conservation, and it is expected to be more prevalent in the future for the great potential to substitute the use of renewable energy for burning of fossil fuels. As we all know, groundwater heat pump (GWHP) and aquifer thermal energy storage (ATES) are typical forms in the area of GSHP and underground thermal energy storage (UTES) respectively. The effect of energy conservation plays an important role in the national energy strategy, but the groundwater environment has been affected and even damaged to some extent because of over-exploitation and unreasonable utilization. This paper reviewed the development from GWHP to ATES worldwide, especially in China and surveyed the situation of groundwater utilization from GWHP. It shows that lack of cognitive ability, scientific constraints and reasonable utilization may bring catastrophic damage to the groundwater resource. Future work should aim at more research on basic problems during the demonstration of applications, such as thermal interaction between pumping and injecting wells, energy transport in the field of well, groundwater contamination, etc. In fact, the characteristics and performance of unsteady and transient heat transfer in the complex underground environment of multi-wells, and their control strategies of the GWHP and ATES systems have been also the most pressing problems. Their explorations and studies will strengthen the theoretical and practical understanding, and guide an orderly, healthy and sustainable development from GWHP to ATES technologies.