A Loss Analysis for a 28% Efficient 520X Concentrator Module
A module efficiency loss analysis has been conducted by comparing the efficiency of the module on-sun (28.2% peak) to the efficiency of the bare cell measured in the laboratory (35.5% peak). This analysis suggests that there are two main loss mechanisms in the module: elevated operating temperature and an optical efficiency less than unity. This analysis also suggests that the effects of spectral and intensity non-uniformity have been well controlled
Numerical and experimental research of the characteristics of concentration solar cells
The development of automatic tracking solar concentrator photovoltaic systems is currently attracting growing interest. High concentration photovoltaic systems (HCPVs) combining triple-junction InGaP/lnGaAs/Ge solar cells with a concentrator provide high conversion efficiencies. The mathematical model for triple-junction solar cells, having a higher efficiency and superior temperature characteristics, was established based on the one-diode equivalent circuit cell model. A paraboloidal concentrator with a secondary optic system and a concentration ratio in the range of 100X–150X along with a sun tracking system was developed in this study. The GaInP/GalnAs/Ge triple-junction solar cell, produced by AZUR SPACE Solar Power, was also used in this study. The solar cells produced by Shanghai Solar Youth Energy (SY) and Shenzhen Yinshengsheng Technology Co. Ltd. (YXS) were used as comparison samples in a further comparative study at different concentration ratios (200X–1000X). A detailed analysis on the factors that influence the electrical output characteristics of the InGaP/lnGaAs/Ge solar cell was conducted with a dish-style concentrating photovoltaic system. The results show that the short-circuit current (Isc) and the open-circuit voltage (Voc) of multijunction solar cells increases with the increasing concentration ratio, while the cell efficiency (ηc) of the solar cells increases first and then decreases with increasing concentration ratio. With increasing solar cell temperature, Isc increases, while Voc and ηc decrease. A comparison of the experimental and simulation results indicate that the maximum root mean square error is less than 10%, which provides a certain theoretical basis for the study of the characteristics of triple-junction solar cell that can be applied in the analysis and discussion regarding the influence of the relevant parameters on the performance of high concentration photovoltaic systems.
The SCARLET light concentrating solar array
In recent years, spacecraft power levels have continued to grow, accelerating the evolution towards higher efficiency photovoltaic devices. Light concentrating arrays enable the cost-effective implementation of recently developed high-efficiency solar cells while providing high array efficiency, protection from space radiation effects and plasma interaction minimization for high voltage arrays. The line-focus concentrator concept delivers two added advantages: (1) low-cost mass production of the lens material; and (2) relaxation of precise array tracking requirements to only a single axis. New array designs emphasize lightweight, high stiffness, stow-ability, and ease of manufacture and assembly. In this paper, the authors address the current status of the SCARLET (solar concentrator array with refractive linear element technology) concentrator program with special emphasis on cost and mass performance trade-offs versus cell type and Sun tracking capability.