Measurements of the Electrical Incidence Angle Modifiers of an Asymmetrical Photovoltaic/Thermal Compound Parabolic Concentrating-Collector

Abstract

Reflector edges, sharp acceptance angles and by-pass diodes introduce large variations in the electrical performance of asymmetrical concentrating photovoltaic/thermal modules over a short incidence angle interval. It is therefore important to quantify these impacts precisely. The impact on the electrical performance of the optical properties of an asymmetrical photovoltaic/thermal CPC-collector was measured in Maputo, Mozambique. The measurements were carried out with the focus on attaining a high resolution incidence angle modifier in both the longitudinal and transversal directions, since large variations were expected over small angle intervals. A detailed analysis of the contribution of the diffuse radiation to the total output was also carried out. The solar cells have an electrical efficiency of 18% while the maximum measured electrical efficiency of the collector was 13.9% per active glazed area and 20.9% per active cell area, at 25˚C. Such data make it possible to quantify not only the electrical performance for different climatic and operating conditions but also to determine potential improvements to the collector design. The electrical output can be increased by a number of different measures, e.g. removing the outermost cells, turning the edge cells 90˚, dividing each receiver side into three or four parts and directing the tracking, when used, along a north-south axis.

Advances and limitations of increasing solar irradiance for concentrating photovoltaics thermal system

“…suns. The study demonstrated that the PV cell can still reach a high temperature even with a low concentration ratio, where the electrical efficiency was measured to be 20.9% at 25 °C [47]. The dependency of the electrical efficiency on the cell temperature is -0.4%/K, as illustrated in Fig.…”

“…The experimental results of the different semiconductor materials are listed in Table 1. [46][47][48][49].…”

Effect of Reflector Geometry in the Annual Received Radiation of Low Concentration Photovoltaic Systems

“…The PVT Solarus collector belongs to the compound parabolic collector (CPC) type, which is commonly known as the maximum reflector concentrator (MaReCo) family [9], and it is widely described in the literature [10][11][12]. It is formed by a reflector with two asymmetrical truncated parabolic sections separated by a circular section (compound parabolic concentrator, CPC), a flat receiver with solar cells in both sides and bi-facial absorbers.…”

“…To reach to a new design that receives nearly as much as the flat collector, but at lower costs, will represent an upgrade. Three new geometries were proposed for lower latitudes 11 . Two of them present pure symmetric geometries (parabolic reflector and receivers symmetrically placed) and the third has a parabolic reflector but with an asymmetrically placed receiver as standard MaReCo (truncated CPC with a bifacial receiver plus parabolic and circular reflectors).…”

A review of concentrated photovoltaic-thermal (CPVT) hybrid solar systems with waste heat recovery (WHR)

“…At peak hours, the measured efficiency was 20.9% per cell area and 13.9% per active glazed area. Several prototypes of the CPVT collector (with reflective/transparent end gables and different cell sizes) were further tested and compared [95], in order to minimize the impact of shading at oblique solar incidence angles. The measured results showed that, at large incident angles, the system with transparent end gables and larger cells performed better.…”