Bifacial solar panels increase overall efficiency primarily through their unique design that allows them to capture sunlight on both their front and back surfaces, unlike traditional monofacial panels which only absorb light on one side. This dual-sided light absorption enables bifacial panels to harness reflected and diffused sunlight from their surroundings, significantly boosting their energy output.
Key design features influencing their efficiency include:
- Dual-Sided Photovoltaic Cells: Bifacial panels have solar cells on both the front and rear, with the back side exposed through a transparent or glass back sheet to capture albedo—light reflected from surfaces such as snow, sand, concrete, or white roofing materials. This design can increase energy yield by up to 30% compared to standard panels depending on installation conditions.
- Use of Transparent Materials and Double-Glass Construction: The rear side often consists of glass or a clear backsheet, allowing light penetration and improving durability. The double-glass construction enhances resistance to environmental factors, contributing to a longer operational lifespan and overall reliability.
- Optimized Mounting and Installation: To maximize rear-side light capture, bifacial panels are typically mounted elevated and angled to allow sunlight reflection onto the back surface. They perform best over reflective surfaces and open spaces, with ground-mounted or utility-scale installations favored over typical rooftops, where limited reflected light reaches the panel’s back. Installation systems use minimal framing and narrower supports to reduce shading on the rear side and improve light access.
- Enhanced Performance with Trackers: When paired with solar trackers that adjust the panel orientation to follow the sun’s movement, bifacial panels can see efficiency gains up to 27%, as trackers maximize light incidence on both sides throughout the day.
- Albedo Dependency: The effectiveness of bifacial panels strongly depends on the reflectivity (albedo) of the surface beneath and around them. Light-colored, reflective surfaces (like white EPDM roofing, snow, or concrete) increase the rear-side irradiance substantially, while darker, absorbent surfaces (like asphalt) reduce the bifacial gain.
- Durability and Extended Life: The design with glass on both sides and robust construction materials contributes to a lower degradation rate over time, which improves long-term energy production and reduces lifecycle costs.
In summary, the design of bifacial solar panels—featuring photovoltaic cells on both sides with transparent backing, minimal rear shading, and installation over reflective surfaces—enables them to utilize more of the available sunlight, including reflected light. This leads to an overall efficiency increase of approximately 5-30% over traditional panels, depending on the site configuration, mounting, and environmental conditions.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-design-of-bifacial-solar-panels-influence-their-overall-efficiency/
