Thermodynamic and economic analysis of a novel solar-driven integrated cooling, heating, power, and desalination unit for vertical farming system

Vertical farming plays a crucial role in addressing global food demands as the population grows. Although it promotes sustainability by conserving water and minimizing land use, vertical farming still necessitates substantial amounts of electricity, freshwater, and advanced ventilation systems to maintain optimal growth conditions. This research presents a solar-powered system designed for a 1000-square-meter vertical farm in Bushehr, Iran, featuring integrated cooling, heating, power, and desalination units. The system integrates parabolic trough solar collectors with thermal storage, enabling continuous operation. It employs an organic Rankine cycle coupled with an ejector refrigeration cycle for power generation and cooling, while excess heat is repurposed for desalinating seawater. Performance evaluations were conducted using thermodynamic principles and economic analyses, focusing on exergy efficiency (25.09 %), thermal efficiency (14.62 %), payback period (7.53 years), return on investment (34.53 %), and the necessary parabolic trough solar collector area (approximately 6276 square meters). Design parameters affecting these metrics, including turbine inlet and outlet pressures, condenser temperature, and heat transfer coefficient of storage tanks, were also examined. The findings highlight the system's potential as a sustainable farming solution, offering high efficiencies and a favorable financial return.