Enerize Corporation has developed a new design for photovoltaic (PV) modules using a proprietary transparent polymer material to replace conventional glass, resulting in an increase in conversion efficiency of more then 20%.
The polymer increases efficiency due to higher transparency and concentration of incoming light, while providing resistance to degradation by UV and ionizing radiation, lower cost, reduced weight, and improved mechanical strength, according to the company.
Conventional glass has several disadvantages as a protective covering for photovoltaic modules. Glass is relatively heavy, brittle and reflective. Light reflected from the glass surfaces (both exterior and interior) does not reach the solar cell underneath, and glass tends to block ultraviolet light, thus reducing the energy that can be obtained from this part of the spectrum. PV modules that use glass comprise a multi-layered structure that is more expensive and complicated to manufacture as compared to the new polymer coated design.
The new highly transparent polymer material can be applied directly to the PV module surface at low temperatures, eliminating the need for the adhesives required with glass and some other polymers. This eliminates the multi-layer structure including the reflective surfaces present with glass. No glass is used with this polymer coating. The polymer can be formed as a flat smooth surface or as a “crinkle coat”. The “crinkle coat” version further enhances photon collection efficiency due to the light concentrating effect of the polymer material and its surface morphology.
In conventional designs using glass, the efficiency of the PV module can be decreased by 7% or more as compared with a PV module without a glass covering. Use of the Enerize polymer encapsulation and protective coating materials can increase conversion efficiency compared with the same PV module having no covering.
As compared to a PV module laminated with glass having an efficiency of 16.45%, a PV module with the same type of solar cells coated with Enerize polymer material has an efficiency of 21.2%.
Enerize transparent polymer materials and coating technologies can be used to improve conversion efficiencies and overall performance of mono-crystalline, multi-crystalline, amorphous silicon photovoltaic and non-silicon based PV modules such as CIGS (copper indium gallium selenide).
(A hat-tip to David!)