A comprehensive assessment of cost-optimal heat supply to new low-energy building areas in Sweden

Abstract

Buildings in Sweden use a large share of energy produced nationally but produce a low share of direct carbon emissions due to high market share of heat pumps and district heating (DH), which uses biomass. Sweden has set stringent energy and climate goals for 2045 prescribing, among other things, reduced energy consumption in buildings. Consequently, new building areas are built based on low-energy building (LEB) standards. These buildings require space heating on cold days and hot water generally. There are four main heat supply options for these areas: (1) individual heat devices (2) decentralized DH, (3) connection to a nearby centralized DH, and (4) prosumers. In this study we developed and applied a dynamic energy system optimization model and designed a systematic analysis to assess cost-optimal heat supply to LEBs in the long-term, while addressing the climate targets. The results showed that low temperature decentralized DHs (LTDDH)s have the lowest cost and individual heat devices have the highest cost of heat supply to LEB areas. The cost-efficiency of LTDDH increases with if prosumers exist in more densely built LEB areas with higher annual heat demand. Additionally, stringent climate policy scenarios can further decrease the cost of LTDDH in LEB areas.