A virtual platform to evaluate policy scenarios targeting environmental impacts from household consumption

Abstract

Household demand for products and services triggers a multitude of economic activities along the supply chain of each product and service, involving the use of resources and the release of emissions. Assessing environmental footprints of households is thus an important basis to identify environmental strategies. This study aimed to develop a comprehensive regionalized bottom-up model for Switzerland which is able to assess the environmental impacts induced by individual households. The purpose of this overarching model is to provide a virtual platform for detailed scenario analysis which shall support effective political decision making on different scales. Three existing bottom-up models were merged: a building stock energy model, an agent-based transport simulation and a household consumption model. All of them were tested and evaluated beforehand. The physically-based building energy model estimates space heating, hot water and electricity demand for each residential building based on simplified energy balances as a function of time, site, climate data, building characteristics, surrounding topography and 3D-geometries. The mobility sub-model builds upon the simulation results of MATSim, an agent-based traffic simulation framework. The application of MATSim to Switzerland reproduced the mobility behavior of the Swiss population and provides spatio-temporal information on chosen traffic modes and driven routes for each agent. The third sub-model derives a detailed financial budget for each Swiss household and enables the quantification of consumption of food, consumables, and other goods and services. Linking these sub-models with environmental background data enabled to compute an environmental profile for each individual household in Switzerland. The application of this model to the current situation of Switzerland revealed interesting differences between individual households, different regions and different consumption areas. These differences emphasize the importance of bottom-up modelling. However, the potential of this model goes even beyond: The high resolution of all three sub-models permits detailed scenario analysis. The component-based approach of the building sub-model facilitates the investigation of detailed refurbishment scenarios with regard to improved insulation or new heating technologies. The link to MATSim allows for analyzing future mobility scenarios, ranging from electric car penetration and increased home office activities to autonomous vehicle systems. The household consumption model considers these scenarios not only in the context of total household consumption and potential burden shifts between consumption areas (rebounds), but enables additionally the simulation of further scenarios such as changes in diets. In follow-up research, the interlinking of the three sub-models is currently reinforced in order to form a complete agent-based model for Switzerland in which agents can manage their expenditures and interact with the mobility system as well as with buildings. This improved model will allow for analyzing also dynamic scenarios such as the diffuse penetration of new technologies and associated rebound effects. By covering the variability of household behavior and quantifying the demands and environmental footprints of households in the current state and in scenarios, the model identifies reduction potentials of environmental impacts and delivers important insights for the derivation of constructive and targeted environmental strategies for different regions and different household types.