Concentration photovoltaic optical system irradiance distribution measurements and its effect on multi‐junction solar cells

Abstract

This paper proposes an indoor procedure based on charge-coupled device camera measurements to characterize the non-uniform light patterns produced by optical systems used in concentration photovoltaic (CPV) systems. These irradiance patterns are reproduced on CPV solar cells for their characterization at concentrated irradiances by using a concentrator cell tester and placing high-resolution masks over the cells. Measured losses based on the masks method are compared with losses in concentrator optical systems measured by using the Helios 3198 solar simulator for CPV modules.

Understanding causes and effects of non-uniform light distributions on multi-junction solar cells: Procedures for estimating efficiency losses

“…The irradiance profile of the three optical system under study was evaluated and captured over the entire CCD spectral range (400-900 nm) and also over both top and middle wavelengths (if including appropriate band-pass filters during the measurement) (22). The PAR values for these experimental profiles are presented in Table 1.…”

Assessment of the optical efficiency of a primary lens to be used in a CPV system

“…Significant results from those experiments and descriptions of the methods have been previously reported in several articles (Antón et al, 2003;Askins et al, 2011;Herrero et al, 2012). This paper aims to show this knowledge in a more comprehensive and systematic way to make it more useful to the reader.…”

“…Furthermore, the method allows the estimation of non-uniform photocurrent distribution in every subcell within a MJ solar cell. This information results crucial to analyze the losses in the electrical efficiency of a system (comprising the lens under evaluation) due to low fill factor caused by high effective series resistance (Espinet, 2012;Herrero et al, 2012;Kurtz and O'Neill, 1996;Victoria et al, 2013) and to current losses due to high lateral resistance. Of course the method can be used to evaluate both classic imaging lenses and non-imaging lenses.…”

A novel scanning lens instrument for evaluating Fresnel lens performance: Equipment development and initial results

“…The spectral response of the multi-junction solar cell was also studied to confirm its similarity with that of the component reference cells. The light spot size for each lens is also measured using a CCD camera (with long/short pass filters), in order to confirm that the multi-junction cell is large enough to measure the complete area of light concentrated by the Fresnel lens [5].…”