Investigation of optimal hybrid energy systems for detached single family house districts under different boundary conditions

Energy planning at the municipality level has come into focus in Germany with the introduction of the “Act for heat planning and the decarbonization of heating networks”. A primary challenge in this process is identifying optimal energy sources and producers. This investigation delves into the optimal design of hybrid energy systems for districts comprising detached single-family houses, considering three different building ages and varying energy costs. The optimal hybrid energy system is identified for 4158 scenarios using multi-objective optimization, considering both total annual costs and carbon dioxide emissions. The results show, that biomass boilers present the highest capacity in the optimized hybrid energy system in all investigated scenarios. The optimal capacity of heat pumps depends on the building class and the corresponding supply temperature. In the oldest building age class they are not selected as part of the hybrid energy system, whereas they cover up to 28.2% in the newest building age class. Additionally the results reveal a strong positive correlation with the capacity of the Photovoltaics showing a correlation coefficient of 95.39% for the newest building age class. The findings underscore the advantage of hybrid energy systems for detached single family house districts, as in 99% of the scenarios the optimal system comprises of three or more different heat producers.