Recent advances and emerging research trends in Solar Organic Rankine Cycle systems (SORC)

Solar Organic Rankine Cycle (SORC) systems represent a viable solution for converting low-to-medium temperature thermal energy into power. This study evaluates recent advances in SORC technologies by analysing a dataset of over 120 systems (2005–2025) to identify performance metrics, technical barriers, and optimization strategies. The study maps the correlations between solar collector families, ranging from non-concentrating (Flat Plate-FPC, Evacuated Tube-ETC) to concentrating technologies (Parabolic Trough-PTC, Linear Fresnel-LFC, Compound Parabolic), and the thermodynamic properties of suitable organic working fluids. Key components, including thermal storage integration, expander types, and condenser cooling methods, are assessed based on their impact on overall efficiency, which peaks at approximately 21% for high-temperature configurations. This analysis transitions from qualitative description to quantitative benchmarking, resulting in a “collector–fluid–storage” selection matrix that identifies robust design combinations and addresses critical performance gaps. Key findings confirm that PTC and LFC systems paired with toluene or siloxanes reach system efficiencies of 10-21%, while FPC and ETC configurations with R245fa remain suitable for low-temperature applications at 1-8%. Capital costs span 4300-11,500 €/kWe depending on scale, with levelized cost of electricity reaching 0.12 €/kWh for optimized medium-scale plants. Future priorities are high-conductivity phase-change composites and low-GWP working fluids experimentally validated at high temperature. • Benchmarks set for 120 SORC systems from 2005 to 2026. • A new selection matrix identifies optimal SORC design pairings. • Quantitative gaps found between simulated and experimental performance. • System efficiency peaks at 21% for high-temperature configurations. • LCOE reaches 0.12 €/kWh via optimized medium-scale system designs.