Design and characterization of a daylighting system: A solar concentrator (a Fresnel lens) coupled to optical fibers

Abstract

Morocco has demonstrated a strong commitment to transitioning from a fossil fuel-based economy to renewable energy sources, positioning energy efficiency as a critical pillar of this shift. This study presents the development of an innovative, cost-effective daylighting system using fiber optics. The system is based on a solar concentrator consisting of Fresnel lenses, a simple sun-tracking mechanism, and inexpensive polymethyl methacrylate (PMMA) optical fibers. Preliminary tests carried out at the Mechanics, Energy Efficiency and Renewable Energies Laboratory (L.M.3.E.R.), Faculty of Sciences and Techniques Errachidia, Morocco have shown that the system can provide sufficient lighting levels for office tasks in areas with predominantly clear skies. According to calculations, the intensity of solar radiation captured by the system can reach 666 W/m2 at 3p.m. in July. Experimental results revealed that the system achieves 50 lx under clear skies, with fiber attenuation of 150 dB/km. To achieve these performance levels, the system requires 25 Fresnel lenses measuring 9 cm2, and 75 optical fibers with a diameter of 3 mm and a length of 2 m. These findings demonstrate the system’s potential as an affordable and sustainable solution for daylighting applications, contributing to energy efficiency goals.

Keywords

• Daylighting system
• Solar concentrator
• Fresnel lens
• Optical fibers