An international research team found that residential air-to-water heat pumps retain significant operational flexibility even during extreme winter conditions, as they rarely operate at their maximum capacity. The study of 761 systems in southern Germany shows that intelligent control and thermal storage strategies could enable grid-friendly load shifting while reducing peak electricity demand.
Researchers from the Technical University of Munich (TUM) and Austrian heating specialist iDM Energiesysteme have analyzed the performance of 761 residential air-to-water heat pumps in southern Germany and have found that even during peak winter conditions, the systems rarely operate at their maximum technical limits, offering “measurable” flexibility for grid-friendly load shifting.
“We observed that, even during the coldest periods examined, heat pump systems rarely run continuously at their maximum technical capacity, leaving room for flexible operation and grid-oriented load shifting,” corresponding author Thomas Haupt told pv magazine. “To fully exploit this flexibility potential, thermal storage systems need to be operated strategically in response to grid conditions.”
For their analysis, the researchers selected the Central Bavaria region, as it ensures sufficient heat pump datasets and limited altitude-related temperature variations. The analyzed area covers approximately 120 km × 150 km between Nuremberg and Munich and includes measurements from 31 DWD weather stations. Two cold periods, February 2021 and February 2023, were selected based on historical temperature analyses and heat pump data availability.
