Harvesting and Transmitting Natural Light for Indoor Use




Ramirez, Ricardo

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Currently, humanity is faced with the trilemma of an unstable food supply, shortage of resources, and environmental degradation putting the world at an inflection point where it is necessary to change to new agricultural concepts to reduce environmental exploitation and enhance the quality of life through unadulterated food of high nutritional content. Climate-controlled environments for agricultural use provide a way to reduce precious resources like water and fertilizers but lack electrical energy efficiency from reliance on artificial lighting. The typical renewable energy approach is to install photovoltaics to convert solar energy into electrical energy resulting in single-digit energy efficiencies from two energy conversions. Alternatively, optical fiber can be used to eliminate energy conversions at the expense of geometrical and material-based attenuation. To enable this strategy an optical fiber daylighting (OFD) system is installed close to a vertical farm with the primary function of tracking the sun to concentrate the sun’s rays into a launch coupler and subsequently the optical fiber for total internal reflection (TIR) thereby transferring photosynthetic active radiation (PAR) downstream for essential energy in the proper configuration for indoor cultivation. Commercial OFD systems have limited optical area and lack robustness for agricultural use. A cabled-driven parallel manipulator for solar applications is introduced to resolve the availability of optical area and robustness. Low cost poly (methyl methacrylate) PMMA optical fiber was utilized as the primary component for light transmission. The purpose of this study is to design and investigate a parallel manipulator topology for OFD tracking and characterize PMMA optical fiber through preliminary field studies.



solar lighting, optical fiber daylighting


Ramirez, R. (2021). Harvesting and transmitting natural light for indoor use (Unpublished thesis). Texas State University, San Marcos, Texas.


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