We are gradually moving towards greener environment with rapid Solar PV installations around the world but at the same time our industry is going through several hurdles and one of them is the “SYSTEM COST”. And when it comes to System cost, first thing comes in our mind is “SOLAR PV MODULE”. In this competitive era, cost reduction is very important in supply chain but at the same time Balance of Cost and quality is also necessary.
These days, “Solar PV Backsheet” is very hot topic where various renowned Solar Backsheet manufacturers are locking the horns with each other to take bigger market share. Some of the backsheet manufacturers are using cheap materials to reduce the cost and launched new models of backsheets with new types of materials which only have the advantage of cost but not the quality. In short, they are only considering short term profits and not considering the 25 years life span of Solar PV Module.
Solar Backsheet OLEFIN Layer/O Film Cracking:
We have came across with the issue of Olefin (O film) inner/Cell Side layer Crack Issues in Solar PV Backsheet found in Modules Installed in Rajasthan (Western Region of India) which is typically high heat & UV area.
- During Inspection of approx. 400 Modules, around 38 modules have cracks in inner/Cell Side layer (Olefin) of backsheet.
- Main point of concern here is that this installation is just 1 year older.
- Reason of cracking of O film is UV exposure and that would also results in further cracking of Middle Layer (Insulation layer).
- Solar Backsheet is the combination of different materials where Inner/Cell side layer main functions are adhesion with EVA along with blocking of UV coming from front/Cell side.
- Olefin or Polyolefin contains lots of Tert hydrogen bond which breakdown and yellowing under UV exposure of the wavelength below 330 nm.
- TI of Olefin/Polyolefin is less than 90°C and that result in degradation quickly. At the same time, TI of PET is 125°C.
- Melting Point of Olefin/Polyolefin is only 120°C. At higher lamination temperature(145°C to 165°C) and pressure make the ribbon pass through the thermoplastic O/PO layer. After the lamination, thermoplastic Olefin/Polyolefin layer losts its parts of electrical insulation function. This point is mainly regarding PO film where it is being used as insulation material on the place of PET.
- This Inner layer cracking would results in higher degradation of Module along with bad insulation in next 3 to 4 years and hence the project would go into huge losses.
“Only Cost reduction is not important by using low grade/incompetent material which results in losses for end user but balance of cost & quality is important & required for Solar PV Industry”.