Energy performance of a smart district energy system: measured performance of integrated heat pumps, PV, and CHP in existing multifamily buildings

A smart energy concept was developed and implemented for a district of 5 existing multi-family buildings, combining heat pumps (HP), photovoltaic (PV) modules and combined heat and power units (CHP) to achieve energy- and cost-efficient operation. Measurement data from 2024 show that local power generation via PV and CHP significantly improves electrical self-sufficiency by reducing electricity imports. The HP system operates efficiently, achieving a seasonal performance factor of SPF = 3.1. However, domestic hot water preparation remains potential for improvement due to the continued high reliance on the gas boiler. The integrated energy concept, including sector coupling (Power2Heat) and local electricity production, was successfully demonstrated, with 88 % of the electricity used for heat generation was produced within the district. Nevertheless, the system still heavily depends on fossil fuels. Compared to the previous system (old gas boiler, electricity from the grid), emission reductions vary depending on the assumed CO2-intensity of the electricity mix. Therefore, dynamic CO2 emissions should be considered during the system design phase, as they lead to regionally specific optimization strategies.