Energy supply for the building stock of tomorrow – A case study

Abstract

Reducing energy consumption and using renewable energy sources for the building operation is crucial to achieve lower overall greenhouse gas (GHG) emissions. In this case study we conduct a building energy system optimisation for a new residential district in Darmstadt, Germany under different boundary conditions using the optimisation software Sympheny. Boundary conditions of the year 2023 lead to similar results to the owner’s plan, which is mainly based on natural gas-fired cogeneration plants. However, different scenarios with predicted emission factors and energy prices for 2050 lead to a shift towards the usage of renewables. As planners tend to use current boundary conditions for their calculations, we assess the possibility of switching to a renewable heat supply after the expected life span of the cogeneration plants. The obstacles identified mainly concern the temperature level, but also the space that will not be accessible at that time. The results emphasise (1) that the decarbonisation of space heating in Germany goes hand in hand with the need to decarbonise the electricity grid and (2) the need for planners to start considering future developments as part of building energy system planning.