The efficiency of solar glass is evaluated using the following parameters:

• Optical transmission
  Transmission measurement for wave-lengths in the range 0,29 µm to 2,5 µm. For pv applications the transmission measurement can be corrected for the reflection at the glass rear surface.

• Weighted transmission
  Calculation based on the optical transmission measurement and different weighting spectra result in specific rating numbers; for example the solar transmission from a weighted integration with the AM1.5 solar Spectrum (ISO 9845-1).

• Incident angle modifier
  Determination of transmission in relation to the angle of incidence. Specific measurement equipment is used for solar thermal or pv applications.