Spectral Correction Model Validation Using Spectroradiometer Measurements for CdTe Modules

Photovoltaic module performance changes in spectrum due to the availability of precipitable water, air mass contents in the atmosphere, which change the spectral irradiance at different wavelengths. The module performance variability, which is caused by the short-term weather change and seasonality, affects the energy prediction modeling. A parametric model for spectral correction based on the precipitable water and the air mass was developed previously to capture this phenomenon. However, the model was not validated using field test measurements. In this paper, the previously developed spectral correction model is validated using the spectroradiometer measurements collected from the First Solar Ohio test site. Comparison between irradiance-weighted spectral correction calculated from the model and from the measured spectral data over two year duration shows reasonable agreement (0.16%) in Ohio climate.