Efficient, Real-Time Global Spectral and Broadband Irradiance Acquisition

Two global solar spectral irradiance meters (SolarSIM-Gs) were deployed and tested at the National Renewable Energy Laboratory in Golden, USA from 18 September to 6 October 2017. The instruments were installed in the global horizontal orientation at the Solar Radiation Research Laboratory and their measurements were compared against colocated secondary reference spectroradiometers and secondary standard pyranometers. The SolarSIM-Gs' spectral global horizontal irradiance (GHI) accuracy was shown to be <; 5% on average per wavelength in the 290-1650 nm range for over 1,900 analyzed spectra. The broadband GHI measurement accuracy for two instruments was shown to have mean bias and standard deviation of 0.97, 1.23 W/m
²
and 5.27, 5.65 W/m
²
, respectively, for over 10,000 analyzed data points.