Due to their limited angular acceptance, and use of spectrally sensitive multi-junction solar cells, high concentration
photovoltaic modules represent a challenging measurement task. In collaboration with Instituto de Energia Solar at the
Universidad Politecnica de Madrid, SolFocus has designed and manufactured an industrialized solar simulator for
characterization of high concentration photovoltaic modules. The simulator measures module peak conversion efficiency
and acceptance angle. The simulator uses a Xenon flash source with collimating optics to form a uniform one-sun
illumination covering sufficient area to measure two panels of 1 m2 each, along with reference measurement cells for
spectral and power normalization. The on-sun measurement uses a normal incidence pyrheliometer and temperature
sensors to provide normalization information.
This paper presents an algorithm for normalization of tests performed under factory conditions to IEC 62108 standard
operating conditions (850 W/m2 direct-normal-irradiance, 20 C ambient temperature). After normalization, tested panels
are correlated to actual on-sun performance measurements. We present descriptions of the normalizations applied to both
the factory test method and on-sun test method, and compare the results for a population of over 100 modules. As a
result of normalization and correlation methods, we conclude that the simulator predicts on-sun performance to better
than ±10%, with 99% confidence. The primary source of uncertainty is the normalization of the on-sun data. The
repeatability of the flash test is better than ±2%.