Optical Design of a Novel Polygonal Trough Collector for Solar Concentrating Photovoltaic Applications

Abstract

This paper presents a methodology for the optical design of a novel solar concentrating photovoltaic trough collector, consisting of several flat reflecting segments, joined together in an open polygonal shape. The concentrator reflects the incident solar radiation to a flat receiver, thus forming a photovoltaic module. The system of analytical design equations modeled in this work accounts for the number of segments and their tilt angles, focal length, optical concentration ratio, concentration fraction, height, width and the rim-angle of the collector. The effects of angular deviation between the incoming radiation and tilt angles of the segments, as well as the incidence angle at the receiver, are also accounted for in this work. In order to generalize the results, the parameters are normalized with respect to the receiver’s length. The model is validated by comparing a developed design with measurements taken in a 2D drafting program. The effects on various design parameters of changing the focal length are presented and discussed in detail. A visual and tabular tool comprising eight different designs is illustrated, which can be used to quickly select a design according to the desired application.