Publication | Peer reviewed papers | Potentiale, Bioenergiesysteme, Logistik
Thermo-hydraulic simulation of decentralised solar thermal collectors in a high-latitude district heating system: analysing heat distribution and bottleneck mitigation.
Published 7 July 2026
Citation: Fogelström F, Koubar M, Lichtenegger K. Thermo-hydraulic simulation of decentralised solar thermal collectors in a high-latitude district heating system: analysing heat distribution and bottleneck mitigation. Solar Energy. 7. Juli 2026, 114825
Abstract
Integrating solar heat into district heating systems is an established strategy for reducing greenhouse gas emissions and mitigating fuel price volatility. However, most previous simulation studies rely on simplified network representations and lack high-resolution thermo-hydraulic analyses capable of capturing consumer-level dynamics and hydraulic constraints such as network bottlenecks. This study addresses these gaps by fully dig-italising a medium-sized district heating network using consumer-specific demand data in a state-of-the-art thermo-hydraulic simulation tool. The model is validated against measured data (annual heat load error <1%) and applied to a high-latitude (63 • N) district heating system where solar thermal production is based on real output from an operational pilot solar park. Decentralised parabolic trough collector fields are simulated at strategically selected locations to assess their impact on local heat distribution and hydraulic performance. The findings indicate that decentralised solar fields cover a substantial share of local heat demand and significantly mitigate hydraulic constraints. In the most critical bottlenecked segments, transferred energy and associated flow parameters are reduced by up to 90-100%. Monthly solar production reaches approximately 1.6 GWh, corresponding to a 30% solar fraction during peak summer months, with solar heat spreading achieving 90-100% local coverage in favourable scenarios and 40-50% geographical penetration in less favourable hydraulic conditions. The findings demonstrate that strategically placed decentralised solar collector fields can enhance network flexibility, reduce operational constraints, and support the transition to low-carbon heat supply in high-latitude district heating systems.