Understanding next generation cadmium telluride photovoltaic performance due to spectrum

The outdoor spectral shift factor, sometimes referred to as spectral mismatch factor, is calculated for the next generation of First Solar cadmium telluride, CdTe, photovoltaic modules and compared to the previous generation. A parameterization of the CdTe spectral shift factor as an exponential function of precipitable water is derived using the outputs of the SMARTS model for PV systems in 13 locations. Normalized DC power measurements determined by regression of broadband pyranometers from test arrays are compared to the modeled results indicating increased sensitivity to precipitable water vapor.