Experimental Performance Evaluation of a Hybrid Parabolic Solar Lighting System for Use in Agricultural Environments.

This study presents a solar lighting system designed for indoor farming to provide natural light. The proposed system uses a parabolic dish concentrator integrating with polymethyl methacrylate optical fibers to direct concentrated light into a desired place. A water cooling mechanism is also used to prevent heat transmission to the optical fibers. The indoor sunlight's distribution is studied using a designed darkroom. The evaluation is carried out in 7 days, from November 23 to 29, from 8 a.m. to 4 p.m., to ensure the stability of the system under various weather conditions. The results of the experiments show that the receiver's temperature can remain at 63 °C on sunny days under a clear sky, even when the maximum value of solar radiation is about 982 W m−2 with the highest air temperature of 19 °C. During the experiments, the solar illuminance ranges from a maximum of 118,821.85 lx to a minimum value of 374.9.6 lx. The overall optical efficiency of the system, considering optical components, ranges from 31% to 32% under various outdoor illuminance levels. Overall, it is confirmed that the developed solar lighting system offers a applicable method to naturally illuminate protected agricultural environments, enhancing the quality of the growing crops. [ABSTRACT FROM AUTHOR]