Energy system and cost impacts of heat supply to low-energy buildings in Sweden

Urbanization and population growth increase the demand for new buildings. Sweden has set stringent energy and climate goals for 2045. Consequently, new building areas are constructed based on low-energy building (LEB) standards. These buildings require space heating on cold days and hot water generally. In this study a dynamic energy system optimization model (TIMES model) is applied from the perspective of the Nordic region's energy system. Scenarios were designed and they were integrated into the model to assess energy system impacts of heat supply options to LEBs at the national level in the long term while also addressing the climate targets. The results showed that energy flows and technologies in the heat and power sector depend on the choice of heat supply options to LEBs. These in turn affect the total cost of the entire energy system in Sweden as it fulfills its energy and climate goals. In this paper it was determined that a decentralized low-temperature district heat (DH) supply to LEB areas in Sweden could lead to higher utilization of large-scale heat pumps (HPs) and excess heat (EH) while decreasing system costs and consumption of the electricity used for heating buildings.