Flexible deployment of heat pumps for urban decarbonization in Vienna
Vienna has set the goal of becoming climate-neutral by 2040. A decisive lever is the full decarbonization of space heating and domestic hot water (DHW). This paper presents a portfolio of flexible, heat-pump–based solutions that complement a rapidly decarbonizing district heating system with innovative neighborhoodscale concepts. We outline an iterative planning approach – from vision, feasibility, and concept design to implementation and operation – that systematically integrates local resources such as groundwater, geothermal energy, waste heat, photovoltaics, and seasonal storage. Results are illustrated with realized and ongoing projects in Vienna: (i) Donaufeld, where a central chilling plant provides ~20 °C tempering and recovers waste heat to district heating; (ii) Oberes Hausfeld, a 37 °C heat-source network supplied by the district heating return and groundwater heat pumps; (iii) Village im Dritten, Austria’s largest anergy network with ~500 geothermal probes enabling seasonal storage; (iv) Meischlgasse, a cold local heating network that supplies heating, hot water, and cooling without fossil fuels or a district heating connection; (v) VioPlaza, which recycles heat from cooling and the sewer; and (vi) Deutschordenstraße, a flagship retrofit replacing individual gas boilers with a central plant based on propane heat pumps, geothermal probes, and PV. The case studies demonstrate how smart performance and load management, source optimization, and integrated heating/cooling raise efficiency, cut peak loads, and accelerate urban decarbonization.