Improvements on Spectral Correction Predictive Modeling for CdTe Modules

An updated spectral prediction model is proposed for CdTe modules which includes predictive capabilities for cloud cover while maintaining the simplicity required for plant performance simulations. Clear sky index is used to quantify cloud cover given it can be calculated using existing solar plant simulation software like PV syst and Plant Predict. Initial fitting results show the new model has an irradiance weighted testing RMSE 29.4% lower in the GHI orientation and 56.7% lower in the I-Axis tracking orientation compared to the prior 2-parameter spectral model for CdTe. Monthly and yearly spectral correction comparisons show in all locations except for Miami that the new model predicts expected spectral correction more accurately than the existing model which underpredicts spectral impact.