The workshop day in the frame of the 14th IEA Heat pump conference was used to organise a joint workshop of three IEA research projects HPT Annex 61, EBC Annex 83 and SHC Task 66 to exchange results and present them to a broader audience.
IEA HPT Annex 61 has only a half-year runtime, so far, and focuses on heat pump integration in positive energy district. An overview of the state-of-the-art reveals that PED are still rare, but heat pumps are a dominating system solution for the energy supply in PED. Generic systems for the heat pump integration on district level have been defined. Three case studies of the investigation in the Annex 61 are outlined:
• In Austria a new-built district of 1000 flats contained in 16 social housing buildings in passive house quality is investigated. The buildings are supplied with a ground-water heat pump for space heating and district heating for DHW. One building block is investigated by simulation, and a detailed monitoring on single flat level is performed for one building.
• In Belgium an old railway station has been transformed in the retrofit project “Gare maritime” in Brussels to “the city where it never rains” by building offices and commercial buildings in the old railway station hall. The hall has been optimised for thermal comfort and daylight use, and the buildings are supplied by a ground-coupled heat pump system. The installed large PV system yields the renewable energy to operate the “Gare maritime”.
• In Germany an existing district of about 100 buildings, which is connected to a new heating grid supplied by heat pumps and CHP. The energy concept also incorporates a hydrogen electrolysis to be used locally or fed into the gas grid.
Annex 83 in the Energy for Buildings and Communities (EBC) TCP has a broader scope on Positive Energy Districts. Regarding the technical concepts the presentation comprised the system boundaries and KPIs for the technical and economic evaluations. A further activity is related to develop a uniform data structure for the simulation of districts at different stages from the early planning phase to implementation, monitoring and optimisation. This incorporates also automated workflows for district modelling in order to run technology scenarios.
• As case study the first large scale fully electrified zero/positive energy district in London, Ontario, is presented, which incorporates the first 11 storey net zero energy (NZE) office buildings, 160 NZE plus townhomes, NZE office buildings and a retirement home, electric vehicles, solar car parking/parking towers and DC grids. Research is dedicated to the assessment of PED as well as case studies for multi-level energy management and detailed cost/benefit analysis to document barriers and solutions for the implementation.
Task 66 in the Solar Heating and Cooling (SHC) programme is dedicated to solar energy building, i.e. reach a high solar fraction for the supply of the buildings both for individual new and retrofitted buildings and for building blocks or on community level. Subtasks in the Task 66 comprise definition of requirements and KPIs, an evaluation of a larger number of demonstration cases across the participating countries and a technology portfolio analysis and assessment for solar energy buildings.
• As case study two solar energy buildings with a flat rate rental model, where all energy cost is included in the rent, have been monitored. Optimisation potentials were found for storage design and stratification and user behaviour. The surplus of the two building could also supply surrounding buildings with thermal and electric energy. Further research is dedicated to optimised component design and transfer to other locations.
Funding opportunities for research on PED in the frame of the DUT Partnership on EU level and Mission Innovation on international level have also been presented. PEDs are also a topic in the new Cities TCP and collaboration options will be explored.
The workshop was concluded by an interactive panel discussion, where questions regarding introduction, potentials, challenges and opportunities of PED and heat pump application for new built and existing districts were raised and discussed with the audience. In conclusion, PED are an ambitious concept, which is still in the introduction and implemented examples are rare, but the PED concept could be one building block for the urban transition for a future sustainable energy system.
All workshop presentations are found for download at the Annex 61 website under publications.