A study on the application of solar modules to light shelves to improve generation and daylighting efficiency

Abstract

Many studies have been conducted on light shelves for achieving reduced lighting energy, and solar modules are recently being applied to light shelves to improve their energy efficiency. However, most solar modules have limitations in improving the generation and daylighting efficiency because they are installed on top of the light shelves and controlled at the same angle. Therefore, this study proposes a technique for improving the efficiency of the light shelf using a solar module and evaluates its performance using a testbed based on an artificial solar light radiation apparatus. The proposed light shelf comprises a lower module with a reflector and an upper module with a solar module, which are connected to form a vertical folding structure. The upper module has a daylighting hole to allow the flow of natural light into the lower module. Moreover, the optimal light shelf specifications are derived based on the solar module application and installation method and used as standards to analyze energy savings and the uniformity ratio. Based on the optimal specifications, the energy consumption of the proposed system is reduced by 3.5%–32.7% compared with existing light shelf technologies. Furthermore, the uniformity ratio of the proposed system improves by 15.7%–20.2% compared with other solar module–applied light shelf technologies. These findings prove the effectiveness of the proposed system.