Environomic optimisation of local energy concepts for utility companies under the influence of increased energy prices

In the light of the current gas crisis, decentralisation and decarbonisation of building heat systems has received another drive. Utility companies must adapt their product strategy while regarding both economic and environmental criteria. In this study, we therefore optimise the layout and operation of different building heat systems. We analyse four different energy systems with a fixed composition of technologies for the space heating and hot water supply of a typical multi-family house in Düsseldorf, Germany. The concepts are modelled as MILP optimisation problems with the oemof-based framework ESyOpT. The objective is to minimize the total costs and in addition, in a multi-objective approach we limit the system's CO2 emissions to 90 % of the cost-optimal solution. To investigate the effect of increasing energy prices, we optimise for a 2021 scenario and a 2022 scenario. We find that a reduction of CO2 emissions by 10 % leads to a cost increase of 7-51 % in 2021. For 2022, the cost increase is only 4-23 % but at a much higher cost level. The resulting optimised systems are assessed and ranked under the metrics of the total annual costs and the total direct annual CO2 emissions using three different methods for multi-criteria decision analysis. The results show that the system consisting of a pellet boiler, a solar thermal collector and a heat storage performs best. In fact, this system is the most robust to the price increase and a change in the criteria weights.