After the final results of IEA HPT Project 61 have been presented on a workshop in the frame of the 15th IEA Heat pump conference in Vienna in May 2026, the final results have been documented in two reports summarizing the state of the art of Positive Energy Districts PED and the investigations on heat pump integration in districts carried out in Annex 61. Results confirm that heat pumps due to their unique features are already well established in existing positive energy district. However, despite the good performance achieving a positive energy balance in dense urban areas remains a challenge. Results of the more than 15 monitoring project show that in particular in larger districts, optimization of the heat pump integration exist, and that the system performance can be notably increased. Thus, care should be taken to keep temperature at a minimum level close the required use temperature. The results of the monitoring case studies have also been documented as compact four-page fact sheets.
The documents will now go to a review of the HPT ExCo, and will be published after the revision.