Novel combinations of aquifer thermal energy storage with solar collectors, soil remediation and other types of geothermal energy systems

Aquifer Thermal Energy Storage (ATES) system make use of the groundwater to exchange energy with the building: in winter, groundwater is pumped from the warm well to the buildings heat exchanger and the building extracts heat from the groundwater as energy source for the heat pumps, while the groundwater will be injected in the cold well at lower temperature; in summer, the direction will be reversed and groundwater will be pumped out of the cold well to the heat exchanger, where the building will gather cold from the groundwater. ATES combined with solar collectors at two sites in Belgium and the Netherlands proved to allow for additional efficiencies and energy savings. Pilot sites showed promising results for combining ATES with groundwater remediation by enhanced natural attenuation for chlorinated solvents. Pilot sites were also realized in two countries with a less mature ATES market, Spain and Italy. In Spain an innovative hybrid technology between a closed loop and an open loop system has been tested, allowing ATES to be used also in water scarcity conditions. In Italy, a small scale integration with a cold low temperature district heating system has been realized. Technical and economic performances of the pilots are briefly described. The lessons learnt in the pilots provide useful insights for the replication of these solutions.