Assessment of short-term aquifer thermal energy storage for energy management in greenhouse horticulture: modeling and optimization

In this work, the use of the thermal energy storage in alluvial aquifers is proposed as a sustainable solution for supplying the energy demand of greenhouses. Air-conditioning greenhouses during summer allows for
storing their energy surplus in an underground seasonal buffer that can be used, in winter, for heating via a heat pump. The evaluation of the benefits arising from using aquifer thermal energy storage (ATES) for
supplying the energy demand in greenhouse applications requires the modeling of a greenhouse climate model, heating distribution systems (i.e., heating pipes and coils), a heat pump and the ATES system. The
models are sized to a case study, which is based on a 100 m thick aquifer in the Cretaceous chalk located in Wallonia (Belgium), and are simulated for two years. The first year is only devoted to storage and emulates
the creation of the cold and warm wells. In the second year, the thermal energy stored in the aquifer is recovered according to the needs of the greenhouse (the cold well is used during air-conditioning and
the warm well during heating). Results show that shallow alluvial aquifers can be very valuable and can provide a sustainable solution when heating and cooling greenhouses. However, the greenhouse climate
controller must be correctly calibrated in order to maintain a balanced ATES system. More specifically, greenhouses in the latitude of Belgium are forced to increase their cooling consumption, which is possible
thanks to the flexibility offered by greenhouses. Otherwise, the system may not be sustainable due to the higher needs of heating.