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.
Market Share
As of 2023, the market share of bifacial cells stands at around 70%, as reported by the International Technology Roadmap for Photovoltaic (ITRPV), April 2023 Edition.
However, approximately 30% of bifacial cells are being used in monofacial modules, i.e. modules with a non-transparent back cover. These modules are technically incapable of reaping the benefits of bifacial cell technology.
While monofacial modules currently dominate the market at almost 65%, their market share is on the decline.
The industry trend is now gravitating towards high-efficiency bifacial modules. According to the ITRPV report, bifacial modules will account for approximately 70% of the market share by 2033.
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 utilizes 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.
These advantages include:
Lightweight
Bifacial Glass-Backsheet (G-B) modules are 17% 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%-50%. Transparent backsheet, on the other hand, has a much lower UV transmittance (<1%). 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 minimize 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.
Data credits:
RenewSys R&D
ITRPV, April 2023
Image credits:
RenewSys