Frequently asked questions

The core and outerlayers of our Endurans® HP backsheet are polyolefins. Our backsheet is classified as a “HPO” backsheet, a High-Performance Polyolefin backsheet.

In 2010, Isovoltaic engineered a full-polyamide backsheet: a so-called AAA backsheet, based on co-extrusion. However, the material system was particularly poorly designed, with glass-fiber in the core layer. This resulted in extreme anisotropic properties causing weakness and cracking; and ended in failure with modules losing performance in the field, the product being withdrawn, and Isovoltaic going bankrupt. The industry is still counting the cost of this failure. The truth is that when trusted to responsible and knowledgeable hands, the co-extrusion process is effective and proven for use in backsheets – especially Endurans® HP.

While the individual PV backsheet in question may well have performed for this period, there is one glaring problem: the materials used to manufacture that same brand or model will have almost certainly changed in the intervening years.

In the overzealous quest to drive cost out of solar materials, we’ve seen a culture develop where the Bill of Materials is compromised, with costly results.

The short answer is no. The protective fluoropolymer outer film has halved in thickness from more than 40 to less than 20 microns for most fluoro-based backsheets on the market today. In some cases, the outer ‘protective layer’ is now little more than a polymer coating just around 10 microns thick. Often, the fluoropolymer inner layer has entirely disappeared and been replaced by a non-fluoropolymer film or coating. Even the layer known as ‘f-layer’ – which should create the impression that fluor is still present – no longer contains fluoropolymers in practice.

Traditional backsheets use a PET core. PET material is polar and sensitive to moisture and UV breakdown. 
So PET needs to be protected by an extra outer layer and/or heavy  (expensive) stabilization. Modified polyolefins have non-polar electrical insulation, which results in an extremely low water-vapor transmission rate. They are highly resistant to hydrolysis and UV breakdown. Our backsheets still have an extra outer layer, as EXTRA protection. However, in case the outerlayer is damaged, the strong core remains intact and much more resistant to moisture ingress. 

The polyolefin that forms the base material of our HPO backsheets takes about one million
years to decompose – which certainly explains why – since 2015 – more than 20 million PV modules have been installed
worldwide featuring these backsheets. However, thanks to the unique co-extrusion manufacturing process used, our HPO backsheets are
fully recyclable at the lowest cost – so they never get to decompose. Instead – unlike laminated PET or
fluorinated backsheets – they can simply be re-melted and shaped into new products…