Sizing tool for collective heat pump systems in Near-Zero and Energy-Positive Apartment Buildings
A first version of a decision-support tool was developed to analyze integrated building energy systems by combining insulation measures, ventilation strategies, PV generation, heat pump capacity, and storage options. The tool was applied to a positive energy building (PEB) case in the Overvecht district in the city of Utrecht, evaluating pre- and post-renovation conditions. Validation against measured annual consumptions shows that the model predicts energy demand and electricity production with sufficient accuracy, with the main uncertainties arising from ventilation rates and domestic hot water usage. The tool generates both visual and numerical outputs, including costs, capacities and energy usages, grid congestion, energy positivity, autarky, and CO2 emissions, making it suitable for use by various stakeholders. It provides insight into building performance and energy systems supporting discussions about collective versus individual measures, particularly regarding grid connection limits. The results demonstrate that achieving an energy-positive building with heat pump technology and solar panels is not guaranteed without addressing measures concerning grid congestion, which requires building related measures, properly sizing heat pumps and thermal or electrochemical buffers. While thermal storage can be highly effective within a certain range and may in some cases offer cost advantages, it is not inherently superior to electrochemical battery storage. Its suitability should be assessed case by case, taking into account not only costs but also the required storage volume and associated spatial footprint, which can become a limiting factor at larger scales. Overall, the tool offers a practical framework for decision-making toward energy-positive apartment buildings with collective heat pump and buffering strategies.