The main factors affecting the performance of bifacial solar panels in low-light conditions are as follows:
1. Albedo Effect and Surface Reflectivity
- Bifacial panels capture light on both front and rear sides, so the reflectivity of the surfaces beneath them (albedo) plays a crucial role.
- High-reflectivity surfaces such as snow, sand, light-colored rooftops, or reflective ground coverings increase the amount of diffused and reflected light reaching the rear side of the panels, boosting energy output significantly.
- Conversely, dark surfaces like asphalt or soil have low reflectivity, reducing bifacial gain especially in low-light conditions.
2. Tilt Angle and Azimuth (Orientation)
- The angle and orientation of bifacial panels directly impact how much direct and reflected light they receive.
- Optimal tilt and azimuth settings maximize sunlight and reflected light capture throughout the day, improving performance in diffuse lighting. Poor angles can diminish this advantage.
3. Environmental and Climatic Conditions
- Cloud cover, shading, and temperature influence bifacial panel efficiency.
- Bifacial panels perform better than monofacial ones under diffuse light because they utilize reflected and scattered light more effectively. This results in roughly 15% higher output in low-light scenarios.
- Cold climates with snow cover enhance bifacial output due to high albedo, while very hot conditions reduce overall panel efficiency across types.
4. Installation Height and Complexity
- Proper installation height is important to avoid shading from snow or surrounding objects, which can reduce reflected light capture. Recommended mounting height is around 42.5 inches off the ground to maintain performance.
- Installation must allow sufficient rear-side exposure to ambient light, which can increase labor and planning complexity compared to traditional panels.
Summary Table
| Factor | Impact on Low-Light Performance | Notes |
|---|---|---|
| Albedo/Reflective Surfaces | High reflectivity boosts rear-side capture | Snow, sand, white rooftops are ideal |
| Tilt Angle and Azimuth | Optimal angles maximize total light collection | Poor alignment lowers efficiency |
| Environmental Conditions | Diffuse light and clouds → bifacial advantage | Cold climates with snow help, heat hurts |
| Installation Height & Setup | Proper height minimizes shading, ensures max reflection | Complex installation for best performance |
In essence, bifacial panels outperform monofacial ones in low light mainly due to their rear-side light capture ability, heavily dependent on reflective ground surfaces, proper tilt/orientation, and minimizing shading or environmental losses.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-main-factors-affecting-the-performance-of-bifacial-panels-in-low-light-conditions/
