Abstract
Innovative photovoltaic technologies with spectral sensitivity exceeding the 400 to 1100 nm limits (as currently defined by the international standard IEC 60904-9) are nowadays available on the market. This poses new challenges in the correct measurement of the spectral content of solar simulators and natural sunlight in those wavelength bands that lie outside these limits. This study proposes an extension of the IEC 60904-9 bandwidth by adding two bands in the UV (300-400 nm) and NIR (1100-1200 nm) regions. This new proposed extension is analysed in terms of spectral match, using spectral measurements of Global Normal Irradiance (GNI) acquired during the 6th European Spectroradiometer Intercomparison by eight independent laboratories. A laboratory is selected to provide reference spectra, and the spectral match of the other ones is calculated, both on a single-measurement level and on a daily average level. The intra-day and inter-day variations are evaluated as well. Results show that all investigated laboratories are capable to assure a spectral match well below the ±25% limit corresponding to class-A simulators. When the more stringent, informal class-A+ corresponding to the ±12.5% limit is considered, four out of seven laboratories are still compliant with it.