Effect of supply and demand conditions on the storage utilization for the ATES Triplet

Space heating and cooling is responsible for roughly 25% of our final energy use, therefore it is a necessity to decarbonize our heating and cooling systems. Many technologies for space heating and cooling use a heat pump, making space heating and cooling more dependent on electricity. Since other sectors are similarly becoming more dependent on electricity, a main challenge in the energy transition is electricity grid congestion. This is even more a challenging issue given the season variation within heating and cooling demands.

                Hence, there is a need for a technology that disconnects the heating and cooling demand from electricity use. The Aquifer Thermal Energy Storage (ATES) Triplet is a technology that does just that. The ATES Triplet uses local sources for heating and cooling, such as solar collectors and dry coolers, and disconnects the temporal supply and demand asynchrony with subsurface storage. It has a hot well, for when the heat source either has too much or too little supply to match demand, a cold well for the time when a cold source has either too much or too little supply for direct cooling. Furthermore, it has a third well that prevents thermal pollution of the hot and cold well. Because of this integration, the ATES Triplet system can supply heating and cooling without a heat pump.

                Parametric simulations are presented to give insight into operational behaviour. A systematic variation of heating and cooling demands, injection temperatures, minimum operation temperatures and return temperatures gives insight into requirements to design and operate an efficient and reliable system. These parameters mostly influence either the heat recovery from the hot well, or the temperature in the third well. A lower heat recovery in the hot well results in a higher need for heat generation, and is mainly influenced by the heating demand, the injection temperature, and the cutoff temperature. A higher temperature in the third well results in a smaller need for heat generation, but a higher need for cold generation, and is influenced by the heating and cooling demands, and the return temperatures.