Thermo-economic analysis of a solar-driven organic Rankine cycle utilizing cold deep space as heat sink via radiative cooling

Abstract

The urban heat island effect is still a significant threat, even for solar-driven power generation systems. Hence, this study proposes a solar-driven organic Rankine cycle assisted with a daytime radiative condenser to mitigate the heat island effect and evaluates its energy, exergy, economic viability and seasonal adaptability. The system's performance is optimized for three different refrigerants and compared with traditional air-cooled and water-cooled systems. The study examines how different operational settings and seasonal changes affect the performance and levelized cost of the system. Key findings reveal that lower radiative condenser temperature, along with higher collector outlet temperature and pinch point temperature difference, enhances net power and exergy efficiency for all refrigerants. The proposed system achieves maximum net power output and exergy efficiency with R152a, while isopentane offers the lowest total specific area and levelized cost of energy. Moreover, the proposed system outperforms, achieving approximately 35 % and 16 % higher net power and 14 % and 7 % higher exergy efficiency than air-cooled and water-cooled systems, respectively. Seasonal analysis indicates peak performance in winter months for Varanasi, Kolkata and Jaisalmer, with January and December yielding the most favorable total specific area and levelized cost of Energy metrics across the different locations. © 2025 Elsevier B.V.