A novel concentrating photovoltaic/daylighting control system: Optical simulation and preliminary experimental analysis

A wide range of developed and commercially available daylighting systems have been reported, however, they have just a single function, so they require an extra complex component to adjust daylighting intensity to create a better visual-comfort interior environment seasonally. Thus, in this paper, a novel concentrating photovoltaic/daylighting control system based on the lens-walled compound parabolic concentrator which is made by the transparent material is proposed. It combines both PV and daylighting control for green building design. At noon, when the incidence angle is small and the solar radiation is strong, the majority of the solar radiation can be collected by the PV cell for electricity generation and the remaining solar radiation will act as the daylighting source. In the morning or evening, when the incidence angle is large and the solar radiation is weak, the majority of the solar radiation will pass into the building for daylighting while the remaining solar radiation will be collected by the PV cell for electricity generation. An optical model was built for the ray-tracing simulation by using the commercial software Lighttoolse (R). The prototype of the lens-walled compound parabolic concentrator was manufactured and assembled for the indoor experiment to validate the optical model. To prove the feasibility of the system, the optical and electrical performance of the proposed concentrating photovoltaic/daylighting control system are derived from the simulation and experimental results, and the actual all-day day lighting performance of it is investigated through the software simulation. The simulation and experimental results indicate good electrical and daylighting performance of the concentrating photovoltaic/daylighting control system, and the proposed concentrating photovoltaic/daylighting control system suits all kinds building rooftop designs with different inclination angles, which proves it a wide scope of application.