Recently, the U.S. Trade Representative Office (USTR) exempted bi-facial solar modules from a Section 201 tariff clause. Such products will be exempted from the 25% tariff charge when imported into the United States.
The key differentiator in bi-facial modules is their ability to absorb light from the backside of the panel and generate electricity, a distinguishing characteristic that has qualified them for exclusion. Solar Energy Industries Association (SEIA) has garnered a big win for our industry through their successful negotiation of this exemption.
The exemption will undoubtedly accelerate demand for bi-facial modules in the United States, with buyers expecting reduced module costs due to the tariff exemption (25%), along with higher energy output. Some module suppliers will ramp up OEM manufacturing to meet the demand, seeking to increase profit margins.
Bi-facial module supply will be tight
When a manufacturer switches to double glass structure, bi-facial module production, they face not only increased required capital investment for manufacturing equipment upgrades, but also higher packaging costs. Slower lamination speed also lowers overall production capacity. This has made creating enough supply to meet the current demand a challenge.
Transparent backsheets provide a smart alternative
Some module suppliers are considering a transparent backsheet. Transparent backsheets fit seamlessly into existing module production lines, result in a higher yield rate and offer a host of other advantages over double-glass modules:
- Lighter weight
- Lower labor cost, requiring less man power to handle and install
- Lower BOS cost that reduces racking/tracking system costs
- Higher reliability
- No bowing or deformation, unlike frameless G/G modules that tend to bend over time
- Breathable design that releases moisture and acetic acid, preventing encapsulant degradation while reducing the risk of delamination and corrosion
- Less power loss and longer lifetime
- Lower PID Risk due to a polymer backsheet containing no mobile sodium ions (the cause of shunting PID)
- Lower installation and O&M costs
- G/B with frame is less prone to glass breakage during transportation and installation
- Faster installation with less required man power
Double glass module field failures lead to long-term reliability concerns
Double-glass field failure is not uncommon. In the western and southern parts of China, bending deformation in frameless, double glass modules was found, causing the cells to crack and the glass to break.
In Arizona, U.S., an installation of ten-year-old, double-glass modules showed significant yellowing, delamination of the rear glass from encapsulant and glass breakage. On the frontside, severe delamination and discoloration was also observed.
Transparent backsheets quickly become mainstream
Currently, the most mature transparent backsheet solution is based on Clear DuPont™ Tedlar® PVF film. This transparent backsheet has been adopted by Jinko Solar for its bi-facial Swan module, a winner of the 2019 Intersolar Innovation Award in Germany. Using the Clear DuPont™ Tedlar® backsheet, it offers a front power output of up to 400W and a backside energy gain of up to 20%. That’s equivalent to double-glass modules, but the transparent module is much lighter, easier to install and offers a 30-year power warranty.
In order to avoid the rising price of glass backsheets due to increasing demand, customers should consider using modules with transparent backsheets. Download the 2019 Field Analysis report by the DuPont® Global Field Reliability Program to find out more about the problems associated with glass/glass bifacial modules in the field.
This is a sponsored post from DuPont.