Spectrally resolved DNI measurements: Results of a field comparison of spectroradiometers, component cells and the SOLIS satellite model

One remote sensing and two in-situ methods for quantifying the spectral distribution of the direct normal irradiance and its impact on multi-junction solar cells are compared for three different sites in Southern Europe, on the Arabian Peninsula and in the South West of the USA. For each method, the uncertainty is assessed. The spectral parameter Z is used to quantify the differences between the methods.