Impact of layout strategy and sector-coupling on the multi-criteria assessment of energy technology concepts for residential buildings

Energy system transformation needs decentralisation, decarbonisation and sector-coupling. Local energy systems are often customarily designed using heuristics for the technology layout. However, optimisation of the technology layout and operation is considered a powerful tool. Therefore, we investigate the influence of an optimised layout and the coupling of the electricity and heat sector on economic, ecological and technological criteria. The criteria comprise the annual costs, CO2 emissions, and the energy performance in terms of self-sufficiency and self-consumption. We consider typical energy technology concepts with fixed technology combinations for the heat and electricity supply of residential buildings. The optimisation is performed using a Mixed-Integer Linear Programming under the objective of minimal costs. The assessment is done using the Analytic Hierarchy Process. An optimised layout is found to reduce costs at the expense of emissions and energy performance. In comparison to the heuristic layout, especially the storage sizes differ among the layout strategies. Sector-coupling leads to CO2 emission savings and a higher self-consumption of the PV energy produced within the system. The multi-criteria assessment reveals higher performance scores for heuristically laid out concepts under a local sensitivity analysis of the criteria weights.