  Aquifer thermal energy storages (ATES) are used to temporally store thermal
energy in groundwater saturated aquifers. Typically, two storages are combined,
one for heat and one for cold, to support heating and cooling of buildings.
This way, the use of classical fossil fuel-based heating, ventilation, and air
conditioning can be significantly reduced. Exploiting the benefits of ATES
beyond ``seasonal'' heating in winter and cooling in summer as well as meeting
legislative restrictions requires sophisticated control. We propose a tailored
model predictive control (MPC) scheme for the sustainable operation of ATES
systems, which mainly builds on a novel model and objective function. The new
approach leads to a mixed-integer quadratic program. Its performance is
evaluated on real data from an ATES system in Belgium.
