With the huge thrust on Renewable Energy Segment, a rapid growth of Global Solar PV market has been observed in the last five years. Lot of new demands werecreated - utility scale and roof-top segment have been phenomenal across the World. But often it has been observed that quality issues with the solar module come as an attached nightmare for the Industry. Rampant drive towards reduction of cost of solar power and ignorance about the solar modules' materials aspects and its contribution towards life, have often lead to quality compromises which mostly lead to these problems.
One of the most critical constituent materials used in the construction of a Solar PV module is the backsheet.
The backsheet is the outermost layer of the PV module placed at the non-sunny side of it. While the backsheet contributes only 4-5 % of the total cost of a solar panel, the criticality of a solar panel backsheet is quite high compared to its cost contribution. While choosing any solar panel, one needs to give enough thought in figuring out more about the backsheet. High quality backsheet will ensure solar panels' longevity and ability to survive very difficult environmental conditions for 25 long years.
The backsheet is basically a polymeric laminate that protects the PV module
from UV rays, moisture and other weathering aspects along with guarding as an
electrical insulator. Thus it should have the superlative properties of
protection against moisture ingress, weatherability, mechanical strength,
adhesion, dielectric properties, reflectivity etc. or an optimized balance of
all of these.
Generally, backsheet is a three-layer laminate but there are lot of varieties
available in the market be it the basic protective layers likeflouride-based
polymers, polyesters, polyamides, polypropylene etc. or thickness or combination
of layers. Till decade and half back,Tedlar was the only choice for protective
layers of backsheetsfor solar modules - and it is still the only polymer that
has proved its long-term (25 years or more) reliability in the field.The demand
based economy had driven the backsheet industry to come up with newer technology
based solutions in the form of PVDF which already has a proven track record of
more than a decade.To serve the purpose of cost reduction, industry has seen the
evolution of materials along with layers getting thinner and fewer, removal of
solid innermost layer with PE based solution or usage of coatings. A wrong
choice of backsheet can lead to severe adverse effect on modules and its very
early failure due to backsheet's cracking, yellowing and delamination etc.
SWELECT Energy Systems Limited has it's presence in the Indian
Electrical and Electronics market for more than 35 years and owns HHV Solar,
which is one of the most reputed brands in Indian Solar PV market, mostly known
for its quality of solar modules. The first and foremost ethical approach of
this Company is to abide by the performance commitment of its solar modules for
25 years in reality so that the power producer's investment economics should not
get suffered after a few years. In ensuring the same, the Company has always
insisted on using the best of the constituent materials chosen from across the
Globe as it believes the quality of a module is as good as its choice of
constituent materials. The BoM of SWELECT (HHV SOLAR) modules have always
ensured the use of either Tedlar or PVDF based backsheet having superior
specifications than the minimum requirement, be it the thickness of the core PET
layer or overall thickness or the use of non-melting inner layer or specific
technical parameters like WVTR, peel strength, better UV and sand abrasions
resistance etc. Another important aspect is the choice of laminator i.e. the
backsheet manufacturer. A lot depends on the art and expertise of making the
backsheet. In order to ensure true 25 years' life of the module,SWELECT never
compromises on the choice of materials, even in today's severe price sensitive
Indian market scenario. SWELECT always uses the backsheets manufactured by the
best of brands from across the world which has perfected the technology and have
long presence in the market and well regarded in the Industry. These all ensures
the true longer life during field exposure for 25years in the harsh ambient
The onus of choosing the backsheet in a module still lies with the customers
but it's prudent to remember that a poor quality backsheet can result in
catastrophic failures which pose serious threats to installers and Operation &
Maintenance of the plant, other than the economics attached to the whole
equation of investment.