Abstract
In the past, two-dimensional radiation transfer models (2-D models) were widely used to investigate the optical performance of linear compound parabolic concentrators (CPCs), in which the radiation transfer on the cross-section of CPC troughs is considered. However, the photovoltaic efficiency of solar cells depends on the real incidence angle instead of the projection incidence angle, thus 2-D models can’t reasonably evaluate the photovoltaic performance of CPC-based photovoltaic systems (CPVs). In this work, three-dimensional radiation transfer (3-D model) within CPC-θa/θe, the CPC with a maximum exit angle θe for radiation within its acceptance angle (θa), is investigated by means of vector algebra, solar geometry and imaging principle of plane mirror, and effects of geometry of CPV-θa/θe on its annual electricity generation are studied. Analysis shows that, as compared to similar photovoltaic (PV) panels, the use of CPCs makes the incident angle of solar rays on solar cells increase thus lowers the photovoltaic conversion efficiency of solar cells. Calculations show that, 2-D models can reasonably predict the optical performance of CPVs, but such models always overestimate the photovoltaic performance of CPVs, and even can’t predict the variation trend of annual power output of CPV-θa/θe with θe. Results show that, for full CPV-θa/θe with a given θa, the annual power output increases with θe first and then comes to a halt as θe > 83°, whereas for truncated CPV-θa/θe with a given geometric concentration (Ct), the annual power output decreases with θe.
Highlights
In recent years, solar photovoltaic systems have attracted much attention for electricity generation due to the gradual depletion of traditional fossil fuels and severe environmental issues caused by their use [1]
For full and truncated 1T-compound parabolic concentrator (CPC)-based photovoltaic systems (CPVs)-26/θe, the maximum deviation is 0.35% and 0.18%, respectively; whereas for full and truncated 3T-CPV-26/θe, the maximum deviation is about 0.95% and 0.24%, respectively. This is because the one-reflection model was employed in 2-D model of Yu, and optical loss due to multiple reflections of solar rays on way to solar cells of CPVs is not considered
These results show that 2-D model proposed by
Summary
Solar photovoltaic systems have attracted much attention for electricity generation due to the gradual depletion of traditional fossil fuels and severe environmental issues caused by their use [1]. The high cost of the electricity produced by PV systems still limits their broader worldwide application. Concentrating solar radiation onto a photovoltaic can reduce the solar area per unit output, allowing the cost of the total system to be reduced per unit of energy delivered. Concentrated PV systems are divided into high concentration PV systems (HCPVs) and low concentration PV systems (LCPVs). HCPVs are usually equipped with sophisticated devices for tracking the Sun and cooling the solar cells [2,3], but LCPVs are simple in the structure and easy to control and more attractive
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.