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Optical modelling for concentrating photovoltaic systems: insolation transfer variations with solar source descriptions

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journal contribution
posted on 08.06.2015, 10:28 by Ian Cole, Ralph Gottschalg
Point source, pillbox and circumsolar ratio-dependent extended light source Sun models are used as solar source inputs into an analytical optical ray trace model for the calculation of plane restricted illumination profiles generated by three example lenses. The example lenses are: a low iron soda-lime glass plano-convex lens, a poly (methyl) methacrylate (PMMA) 3-facet Fresnel lens and a PMMA 20-facet Fresnel lens. Significant differences in illumination profiles are found with solar source description variation. Most notably, it is found that chromatic aberrations and spectrally variant effects specific to the multi-junction solar cell architecture are only identified using the extended light source Sun model. The spectral dependency of material optical properties are analysed in the context of the multi-junction cell architecture by means of spectrally weighted averages corresponding to the active range of the sub-cells.


This work has been supported by a joint UK-India initiative in solar energy through a joint project ‘Stability and Performance of Photovoltaics (STAPP)’ funded by Research Councils UK (RCUK) Energy Programme in UK [grant number EP/H040331/1] and by Department of Science and Technology (DST) in India.



  • Mechanical, Electrical and Manufacturing Engineering

Published in

IET Renewable Power Generation


COLE, I.R. and GOTTSCHALG, R., 2015. Optical modelling for concentrating photovoltaic systems: insolation transfer variations with solar source descriptions. IET Renewable Power Generation, 9(5), pp.412-419.


Institution of Engineering and Technology


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