Examples of silicone gel encapsulant application
Types of EVA laminated PV panel failures
| Type of failures | % of total failures |
|---|---|
| Corrosion | 45.3 |
| Cell or interconnect break | 40.7 |
| Output lead problem | 3.9 |
| J-box problem | 3.6 |
| Delamination | 3.4 |
| Overheated wires or diodes | 1.5 |
| Mechanical damage | 1.4 |
| Defective bypass diodes |
0.2 |
Since 90-ies there is evidence of the positive experience of testing and operation of circuits and semiconductor devices, the so-called sealed polysiloxane gels.
Gels represent three-dimensional structure formed during the reaction of low molecular weight polysiloxanes.
VIESH research institute developed the original manufacturing technology of vacuum glazing with a thermoplastic spacers around the perimeter, characterized in that the evacuated cavity is filled with an optically transparent medium in the form of liquid polysiloxane compound, laminable at room temperature on the mechanism of hydrosilylation in the low-modulus gel.
Recently VIESH research institute in cooperation with Traxle Solar Company developed industrial scale technology suitable for multi MW PV panel production plants. The Traxle Solar Company is the only owner of the worldwide license of this technology.
| | EVA | Silicone gel |
|---|---|---|
| Long term operating temperature | -40 +80oC | -60 +250oC |
| UV radiation resistance | low | High |
| Operating lifetime | 25 years | 40 years |
| Laminator energy consumption per hour | 49 kWh | 4.5 kWh |
| Refractive index | 1,482 | 1.406 |
| Transparency for solar radiation | 8% (360nm) | 90% (360nm) |
| Transparency for solar radiation | 62% (400nm) | 91% (60nm) |
| Transparency for solar radiation | 91% (600-1000nm) | 93% (600-1000nm) |
| Corrosive agents - lamination | Acetic acid | no |
| Corrosive agents - ageing | Acetic acid | no |
| Mechanical stress - lamination | Yes | No |
| Mechanical stress - ageing | Yes | No |
| Lamination temperature | +130°C | +20°C |
| Modulus of elasticity | 10.0 N/mm2 | 0.006 N/mm2 |
| Linear coefficient of thermal expansion | 4.0 x 10-4 K-1 | 2.5 x 10-4 K-1 |
