Avoiding Electricity Grid Congestion and Saving Energy by Using a Triple Well Aquifer Thermal Energy System with No Heat Pump

Aquifer Thermal Energy Storage (ATES) doublet systems with integrated heat pumps are a step forward relative to conventional solutions in terms of energy consumption and fossil fuel dependency. However, heat pumps in such systems are responsible for the majority of the energy consumption and put a significant load on the electricity grid. Both factors can pose challenges in achieving the energy transition and predefined climate goals in a timely manner. ATES triplet systems can mitigate both factors significantly. An ATES triplet system consists of three ATES wells, in which heat and cold that are generated by respectively solar collectors and dry coolers are stored in a hot well and cold well, directly at building supply temperature levels. The third well is the buffer well, designed to prevent thermal pollution of the hot and cold wells. This research uses a detailed dynamic integral simulation model to investigate the technical, operational, and financial feasibility of an ATES triplet system for a specific case in The Netherlands. The study also focuses on gaining an understanding of the system dynamics of ATES triplet systems. The created simulation model includes models of the solar collectors, dry cooler, ATES wells, heat and cold consumers in the building, and a building simulation model. The study concluded that a monovalent ATES triplet system is not technically feasible, but with the addition of a relatively small heat pump, the system can be made feasible and reliable to sustain through all expected extreme consecutive climate years. Compared with an ATES doublet system, the ATES triplet system reduces energy consumption and CO2 emissions by 82% and electricity grid peak load by 94%. The total cost of ownership over a 30-year period for the ATES triplet system is 11% higher than the ATES doublet system but is expected to further reduce. Over a 30-year period, CO2 emission reduction relative to the ATES double system is 73%. Multiple alternative scenarios were investigated to get a better understanding of the system and explore variations in system layout for enhanced performance. Also, the potential conflict that can arise between Photovoltaic (PV) panels and solar collectors was investigated and the role that Photovoltaic-Thermal (PVT) collectors can play to mitigate this conflict. The research concludes that ATES triplet systems can be feasible and can provide significant benefits in the form of energy consumption, CO2 emission, and electricity grid load reductions, which can help accelerate the energy transition, and realize climate objectives.