Impacts of ground source heat pumps on peak power in apartment buildings: a case study from Finland

As heat pumps are increasingly adopted to meet decarbonisation goals, they significantly impact electricity demand, particularly during peak heating periods, posing challenges for grid infrastructure management. Understanding the power behaviour of retrofitted systems is critical for addressing these challenges and supporting the efficient operation of distribution networks. This case study explores methods for identifying and analysing retrofitted ground-source heat pump (GSHP) installations in apartment buildings using electricity consumption and outdoor temperature data. To address this, three analytical methods - hourly average maximum power analysis, temperature correlation analysis, and persistence curve analysis - were applied to data from seven buildings in Tampere, Finland. Results confirm GSHP activity through significant peak-power (hourly average maximum power) increases and stronger temperature dependency after installations. While the methods effectively identify heat pumps, challenges remain in predicting individual building power changes due to varying system designs, auxiliary heating sources, and other loads. From the distribution system operator’s (DSO’s) perspective, insights from this study could inform grid planning, infrastructure management, and the development of more balanced tariff models.