A Preliminary Simulation and Experimental Study on the Solid Parabolic Compound Concentrator (CPC) for the Combined PV and Daylighting Application

Architectural daylighting design usually considers the overcast sky condition in the winter. The actual daylighting level could be excessive in summer and this would cause the issue of overheating in buildings. Prismatic panels represent advanced solar shading method with a selective acceptance angle, so they can be designed to reflect away most of direct sunlight at higher solar altitude while allow the diffuse skylight to transmit for daylighting. From the optical principle, the solid dielectric compound parabolic concentrators (CPCs), which are usually used for non-tracking solar concentration can perform the similar function like a prismatic panel. Use of dielectric CPCs for low concentration PV applications has been attracting great interest due to the potential to reduce the cost of a PV system. It would be attractive to incorporate dielectric CPC PV panels with a roof or window for the purpose of combined electricity generation and daylighting control. This study therefore aims to evaluate the dielectric CPC for daylighting application. A commercial optical analysis software Photopia will be used to predict the transmittance values of the dielectric CPC and the common prismatic structure in order to determine the advantage of using CPC for daylighting control. A preliminary test will also be conducted to experimentally compare the real transmittance of the dielectric CPC and the common prismatic structure.