Survey of 53 fifth generation district heating and cooling grids (5GDHC) in Germany
This article presents a survey conducted among utility companies and engineering offices in Germany to collect data on 53 fifth-generation district heating and cooling grids.
Fifth-generation district heating and cooling (5GDHC) grids are a promising technology to decarbonize the heating and cooling supply of buildings and districts. Up to today, only a small number of 5GDHC networks have been built, mostly in Switzerland and Germany. As a result, there are substantial uncertainties and knowledge gaps in the planning and operation of 5GDHC grids.
Herein, a survey is conducted among utility companies and engineering offices to collect data on 53 5GDHC systems in Germany, including technical, economic, and political key figures and design decisions. Results show that 5GDHC grids are mostly planned for small new build districts (less than 100 buildings). The most frequent heat sources are horizontal geothermal collectors (used in 23 networks) and geothermal probes (17 networks). 74% of the surveyed grids provide not only heat but also cold. Typical grids temperatures are in the range of -5–20 °C. The survey results show that the price models as well as political design decisions, such as the obligation to connect to the grid, vary strongly among the districts
The data shows the high potential of 5GDHC grids, with some utility companies having multiple systems in operation. 5GDHC grids have a high potential to contribute to the decarbonization of existing districts, and larger 5GDHC grids are expected in the future. However, the lack of design guidelines for 5GDHC systems and the complexity of their planning process remain challenges that need to be addressed.