Evaluating the Potential for Solar District Heating with Pit Thermal Energy Storage in Sweden

Abstract

Sweden was among the first countries to install solar thermal plants for district heating (DH) as early as in 1970s. However, in recent years, the focus on solar DH installations has shifted primarily to Denmark and Germany, with only one recent installation reported in Sweden. Nonetheless, due to changes in the overall heating market, the use of large-scale storage (both with and without solar heat) is becoming increasingly important. Despite significant advancements in adopting DH systems, the combination of solar DH with PTES is not well studied from Swedish context. The economic and geological prerequisites for the deployment of PTES remain largely unexplored. This paper explores the integration of large-scale solar thermal systems into DH networks in Sweden, particularly highlighting the feasibility and potential of pit thermal energy storage (PTES) systems. Through findings from a national project, this paper assesses the techno-economic-geological viability of PTES alongside solar thermal collectors, providing insights into the project’s methodological approach and initial findings.