What is a Bifacial Solar Panel?
Bifacial solar technology has gained significant attention in recent years due to its ability to boost energy generation by 10% to 30% compared to conventional panels, depending on environmental conditions. Although the concept is not new—it was first proposed in the 1960s, and the first bifacial solar cell was developed and manufactured in 1975—modern advancements have greatly improved the efficiency and reliability of these panels. Typically, bifacial panels are made of mono or polycrystalline photovoltaic cells housed in transparent, durable frames. Their dual-sided design sets them apart from traditional panels, allowing for higher energy production in suitable environments.
How Do Bifacial Solar Panels Work?
The key to bifacial panels lies in their ability to absorb sunlight from both the front and the back. The front side captures direct sunlight, while the rear side takes advantage of reflected light from the surrounding environment. This makes bifacial panels especially effective in areas with high albedo, such as near reflective surfaces like water, snow, or light-colored ground. Many panels also feature anti-reflective coatings on the backside to enhance light absorption. With continued innovations, bifacial solar technology is improving in terms of light capture, durability, and lifespan, making it an increasingly popular choice for residential and commercial solar installations.
What You Need to Know Before Making a Purchase
Some local brands are opting for thick acrylic sheets as a substitute for tempered glass in bifacial solar panels to reduce costs. While this makes the panels more affordable initially, it can lead to significant long-term performance issues. Acrylic, when exposed to prolonged sunlight, is prone to oxidation and can develop a yellowish tint. This discoloration reduces the material’s transparency, which in turn limits the amount of sunlight passing through to the rear side of the panel. As a result, the overall energy output of the panel diminishes over time, affecting its efficiency and lifespan. Unlike tempered glass, which is highly durable and resistant to UV degradation, acrylic sheets may cause frequent maintenance or early replacement, negating the short-term cost savings. For sustainable performance, it is essential to choose materials like tempered glass that ensure longevity and higher efficiency in solar panel installations.
Also read: Top Clean benefits of Solar Panel Installation You Must Know
Bifacial Solar Panel Performance Under Different Conditions
Performance varying Albedo condition:
The performance of bifacial solar panels is highly influenced by the albedo, or the reflectivity of the surface beneath the panels. Higher albedo surfaces, such as snow, water, or light-colored ground, reflect more sunlight onto the back side of the panels, significantly increasing energy output. In high-albedo environments, bifacial panels can produce up to 30% more energy compared to standard monofacial panels. On lower-albedo surfaces, like grass or darker materials, the rear-side gain is reduced, but the panels still outperform conventional solar panels.
Impact of Installation Height and Angle:
The installation height and angle also play a critical role in bifacial solar panel performance. Elevating the panels increases the amount of reflected light reaching the rear side, enhancing energy generation. Higher installations allow more sunlight to bounce back from the surface underneath. The tilt angle must be carefully chosen to optimize sunlight capture from both the front and rear sides. In some cases, adjustable tilt systems are employed to adapt to seasonal variations in sunlight, further maximizing energy output. Panels installed at steeper angles or at greater heights typically see a higher bifacial gain, especially in highly reflective environments.
Maximizing Bifacial Solar Panel Efficiency: Key Tips for Installations
Rooftop Installations
- Increase Panel Elevation: Install panels at a higher tilt or elevate them to allow more reflected light to reach the rear side.
- High Albedo Surface: Maximize albedo by painting the roof white or using reflective materials to enhance sunlight reflection to the rear of the panels.
Ground-Mounted Installations
- Elevate Panels: Elevating the panels by at least 1-1.5 meters allows more light to reflect onto the rear side.
- Reflective Ground Surface: To increase energy yield, use materials like a white cement mixture, white pebbles, and tiles pieces, or install panels on a reflective surface to increase albedo.
Agrivoltaics (Solar and Farming Combined)
- Higher Elevation: Elevate panels significantly above crops to avoid blocking sunlight for plants and increase sunlight reflection to the rear.
- Manage Vegetation: Maintain ground vegetation that reflects light well without overgrowing and shading the panels.
- Water Use: Use water management techniques that increase reflection (such as keeping crops well-irrigated) for higher albedo.
Bifacial Solar Panels vs Monofacial Solar Panels
| Criteria | Bifacial Solar Panels | Monofacial Solar Panels |
| Cost | ₹15.50 per Watt to ₹17.50 per Watt * | ₹14.50 per Watt to ₹16.50 per Watt * |
| Efficiency | 10-30% higher efficiency due to dual-sided light capture | |
| Merits | – Greater energy yield from both sides – Increased durability due to glass on both sides – Suitable for ground-reflective areas and agrivoltaics | – Lower initial cost – Simpler installation – Proven, widespread technology |
| Demerits | – Slightly Higher installation costs – Performance dependent on environmental factors like ground reflectivity | – Lower overall energy output – Vulnerable to shading and dirt on the front surface |
| LCOE (Levelized Cost of Energy) | Lower in the long run due to higher energy generation | Higher over time as energy output is limited to single-sided capture |
| Area Required | Requires less space for the same energy output due to a bifacial boost | Requires more space for equivalent energy generation |
Conclusion
Environments with high albedo, such as reflective rooftops, snow-covered landscapes, or agrivoltaic systems. Their ability to capture sunlight from both sides gives them a significant edge over traditional monofacial panels, with energy gains of up to 30%. While they come with a slightly higher upfront cost, this investment pays off over time through increased energy output, making bifacial panels more efficient and cost-effective in the long run.
Bifacial panels offer better durability with dual-glass construction and perform exceptionally well in diverse conditions, making them a future-proof investment for both residential and commercial solar projects. In the right setting, bifacial panels are a game-changer for maximizing energy efficiency and sustainability, far outperforming monofacial counterparts in the long term