Comparison of CO2 optimised energy systems for a residential building in Germany

The issue of CO2 emissions in residential buildings is a critical problem that requires urgent attention. This paper sheds light on the potential of fuel cell micro-combined heat and power (FCmCHP) systems to substantially reduce CO2 emissions in heating systems in Germany. In addition, the paper conducts simulations for various heating configurations to determine the best control strategies for reducing overall CO2 emissions. Therefore, this paper aims at quantifying and minimising annual CO2 emissions for heating one representative type of residential building in Germany, considering different types of heating. Six configurations of heating systems, including two types of fuel cells, a heat pump, an auxiliary gas boiler, and hybrid systems (heat pump + fuel cell and gas boiler + fuel cell), are dimensioned and simulated for a single-family house. Their control strategies are optimised towards using or generating energy when CO2 reduction potential is highest. This shift to hours with a lower CO2-intensive electricity mix is mainly enabled by using the thermal inertia of the buildings or the hot water storage for heat load shifting. In addition, the operation cost of the different systems is calculated. The study provides a comprehensive understanding of the subject and can offer actionable recommendations for reducing CO2 emissions in residential heating systems. Furthermore, it underscores the importance of taking proactive measures to reduce CO2 emissions in all sectors, including residential heating systems, to combat climate change and achieve a sustainable future.