Calibration of Spectroradiometers for Outdoor Direct Solar Spectral Irradiance Measurements

Spectral measurements are an important aspect of environmental monitoring for photovoltaics, especially concentrator photovoltaics (CPV) that use multi-junction cells with spectrally dependent output. There are only a few reliable sources of spectrally resolved direct normal irradiance (DNI) data in the world since the measurement equipment is expensive and calibration is hard to maintain. For that purpose a high quality data set of spectra with reduced measurement uncertainties have been produced. Evaluation of the uncertainty of both indoor and outdoor spectrum measurements and their origins is presented in the paper. A calibrated system was used to calibrate a second set of spectroradiometers and repeated measurements have been carried out to find the uncertainties of measurement repeatability, positional sensitivity and lamp stability. Then the two measurement systems were used outdoors alongside broadband solar irradiance measurement devices, in order to extract the differences of the spectral measurements between the systems. Finally, a collimator was attached on one of the spectroradiometer systems and measurements were taken using both collimated and non-collimated systems to extract the impact of the collimator on spectral measurements.

PARASKEVA Vasiliki;  NORTON Matthew;  MARIA Hadjipanayi;  GEORGHIOU George; 

2014-01-27

WIP Munich

JRC80607

3-936338-33-7,   

http://www.eupvsec-proceedings.com/proceedings?fulltext=Calibration,    of,    Spectroradiometers,    for,    Outdoor,    Direct,    Solar,    Spectral,    Irradiance,    Measurements&paper=25041,    https://publications.jrc.ec.europa.eu/repository/handle/JRC80607,   

10.4229/28thEUPVSEC2013-4AV.6.35,