Exploring the solar bifacial glass-backsheet technology

In recent years, an increasing number of module manufacturers have shifted towards transparent backsheets due to their numerous advantages over traditional glass modules. 

Bifacial solar PV modules, commonly known as Bifacial solar panels, generate power from both the front and rear, or backside, of the module.  Unlike traditional PV modules, bifacial modules can generate power from both the front and the back, resulting in higher power output within the same space. This has made them a popular choice for many types of installations.

Types of Bifacial PV Modules

To stay aligned with the PV trend and get the most out of your solar panels, bifacial PV modules are an excellent choice. While they require a slightly higher investment, they offer a much higher output in comparison to their monofacial counterparts, thus compensating for the additional cost over the long term.  There are two common methods for making bifacial solar PV modules:

The first involves using glass layers on both the front and rear sides of the panel, referred to as “Glass-Glass PV Modules,” “Double Glass PV Modules,” or “Dual-Glass PV Modules.”

The second approach utilises a glass layer on the front side and a transparent backsheet layer on the rear side of the panel, known as “Bifacial Glass-Backsheet PV Modules.”

Benefits of Bifacial Glass-Backsheet Modules

In recent years, an increasing number of module manufacturers have shifted towards transparent backsheets due to their numerous advantages over traditional glass modules. 

Lightweight

Bifacial Glass-Backsheet (G-B) modules are 17 percent lighter than Glass-Glass (G-G) modules. The reduced weight offers several benefits, including lower transportation costs, reduced risk of breakage during transit, decreased labour expenses, savings in balance of system (BOS) costs, improved efficiency in handling and installation, and lower environmental impact.

Enhanced impact resistance

Bifacial G-B modules use a 3.2 mm-thick tempered glass on the front, delivering superior impact strength and durability in comparison to the 2 mm–2.1 mm thick heat-treated glass typically used in G-G modules.

Anti-UV properties

The glass used in PV modules generally has a UV transmittance of 40 percent to 50 percent. Transparent backsheet, on the other hand, has a much lower UV transmittance (<1 percent). As a result, it blocks a substantial portion of UV radiation, improving the module’s long-term reliability and performance.

Ease of cleaning

The outermost layer of the transparent backsheet features a PVF (Polyvinyl Flouride) film, which provides stain resistance. The backsheet also has hydrophobic properties, encouraging water droplets to easily roll off, carrying away dirt and dust in the process. This helps minimise dirt and dust accumulation on the backsheet surface and ensures minimal impact on energy generation. 

Lower operating temperature 

Unlike glass, the transparent backsheet facilitates heat dissipation from the module’s rear, leading to a lower operating temperature. This, in turn, contributes to the higher power generation. 

Increased daily yield per watt

Thanks to their lower operating temperatures, bifacial G-B modules have the potential to generate more electricity, especially on sunny days when they don’t heat up as significantly during operation.

Corrosion resistance

Glass is susceptible to corrosion in alkaline environments, often leading to white spots or a hazy look. In contrast, transparent backsheet material is designed to endure such conditions without degradation or the formation of white spots.

For more details, visit: https://www.uksol.uk/bifacial-modules