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Solar glass – Certification

Abbildung Glas Zertifikat

SPF has developed two certification procedures specially tailored for solar glass. These procedures include special requirements with regard to the optical properties of solar glass for the two specific applications.

  • Solar Thermal collectors (ST):
    Glass as a transparent cover of insulated solar thermal collectors with a selective absorber.
  • PhotoVoltaic modules (PV):
    PV modules composed of cells made of crystallin silicon directly laminated to the solar glass.

 

For the purposes of a certification adapted one of the above mentioned application, solar glass is graded into different performance categories according to a specially defined glass efficiency value ηGL,ST or ηGL,PV. The following factors are taken into account in the determination of the aforementioned glass efficiency value: optical transmission, incident angle modifier and degradation (transmission reduction due to environmental factors), which are measured and rated according to the specific application. The idea behind it is that when a glass is replaced with another glass in the same performance category no loss of performance should be experienced in the collector or the module.

For transparency purposes all certificates issued are published on our website.
 

Glass efficiency value and classification into performance categories for solar thermal applications (ST)

Untreated
glass
Singlesided
AR-treated glass
Doublesided
AR-treated glass
           
Class U1 ηGL ≥ 0.900 Class Y1 ηGL ≥ 0.925 Class X1 ηGL ≥ 0.950
Class U2 ηGL ≥ 0.885 Class Y2 ηGL ≥ 0.910 Class X2 ηGL ≥ 0.935
Class U3 ηGL ≥ 0.870 Class Y3 ηGL ≥ 0.895 Class X3 ηGL ≥ 0.920
Class U4 ηGL ≥ 0.850 Class Y4 ηGL ≥ 0.870 Class X4 ηGL ≥ 0.890
No solar glass  ηGL < 0.850 No solar glass  ηGL < 0.870 No solar glass  ηGL < 0.890


Glass efficiency value and classification into performance categories for photovoltaic applications (PV)

Untreated
glass
Singlesided
AR-treated glass
Colored
glass
           
Class P1 ηGL ≥ 0.940 Class R1 ηGL ≥ 0.980 Class P CηGL > 0.0
Class P2 ηGL ≥ 0.925 Class R2 ηGL ≥ 0.965    
Class P3 ηGL ≥ 0.910 Class R3 ηGL ≥ 0.950    
Class P4 ηGL ≥ 0.890 Class R4 ηGL ≥ 0.925    
No solar glass  ηGL < 0.890 No solar glass  ηGL < 0.925