Distributed Fresnel Lens–Fiber System for Solar Light Collection and Transmission: Comparable Output Power with Reduced Thermal Loading

Concentrated solar radiation can be transported through optical fibers to remote locations; however, the high thermal load at the concentrator–fiber interface can limit the operation of systems using polymer optical fibers. This work investigates whether distributing a fixed solar collection area among multiple Fresnel lens–fiber channels can mitigate localized heating while maintaining comparable transmitted optical power. Two PMMA Fresnel lens–fiber configurations with the same nominal solar collection area were numerically and experimentally evaluated: a single-channel system and a four-channel system. Non-sequential ray-tracing simulations were used to analyze the optical performance and determine the lens–fiber coupling distances, while outdoor experiments and thermographic measurements were conducted to evaluate the thermal response. The numerical model predicted total output powers of 29.24 W and 31.39 W for the single- and four-channel configurations, respectively. Experimentally, visible melting occurred at the single-fiber entrance after approximately 40 s, whereas the four-channel system operated for more than 5 min without visible fiber deformation. These results indicate that distributing the solar collection area among multiple lens–fiber channels can reduce localized thermal loading while maintaining comparable total transmitted optical power.