A Guide To Bifacial Solar Panels
4 - Minute Read
Jun 27, 2022
While most solar panels harness light from one side, bifacial solar panels gather energy from both sides to improve energy production.
Generating more clean energy from the same number of solar modules sounds great. But what else should homeowners know about this strategy? Let’s take a look at the concept, the technology and the applications.
What Are Bifacial Solar Modules?
Bifacial panels gather sunlight directly on their front side and from surfaces with high reflectivity using solar cells on the back. Think of how sunlight reflects off snow. Snow has a high albedo — meaning that it reflects a large portion of sunlight back into the atmosphere. White roofs and light-colored ground also have a high albedo.
Most bifacial solar modules use monocrystalline cells, but some polycrystalline options are available. Frameless designs are often more durable and carry warranties up to 30 years.
The Advantages Of Bifacial Solar Panels
Bifacial photovoltaic (PV) cells produce more power from the same surface area and capture sunlight that would go otherwise unused.
Many people researching solar panels ask how they generate solar power on cloudy days. While solar panels in general do work on cloudy days, capturing reflected light allows bifacial solar panels to generate more power when there’s less sunshine.
Bifacial arrays that stay in the same position produce about 10% more energy than conventional solar arrays, and bifacial arrays with trackers can generate up to 27% more renewable energy than monofacial modules, according to LONGi Solar. Solar trackers can change the direction of panels to maximize energy production.
How Do Bifacial Solar Panels Work For Homes?
While bifacial solar modules are a terrific concept, they’re not well-suited for most homes. On most roofs, solar modules are mounted on racking that’s just a few inches above the roof. This doesn’t allow enough sunlight behind the panels.
The higher bifacial solar cells sit from the ground, the more reflected light they can capture. This makes them best-suited for situations – most often utility-scale solar farms – where they’re mounted on the ground. Very few homeowners opt for ground-mounted solar panels since roof-mounted panels are typically a better use of space.
There are a few exceptions, though.
Bifacial PV panels can be a viable option when building a solar carport. They can also work well as a roof for shade structures such as awnings or a pergola.
Overall, though, monofacial solar panels are likely to work best for most homeowners who are looking for roof mounted panels.
Are Bifacial Solar Panels Worth It?
Although bifacial solar panels are able to capture more solar energy, they come at a higher price. They cost about 10% more than monofacial modules.
Also, getting the most from bifacial modules requires a tracking system that moves the panels along with the sunlight. This is an expense that might be worth it for utilities or businesses, but not for homeowners. A tracking system may also be too heavy for certain roofs.
In addition, many homeowners prefer roof-mounted solar panels because they save valuable ground space.
Quick Pros And Cons Of Bifacial Solar Panels
Here’s a quick summary of the pros and cons of bifacial solar panels:
Bifacial Solar Panel Pros
Improved efficiency: Capturing direct sunlight and reflected light allows bifacial panels to generate more electricity in the same amount of space as monofacial solar panels. Conventional monofacial modules with opaque backsheets only collect direct solar radiation.
Durability: Many bifacial solar panels have tempered glass on both sides, making them more heat and wind resistant.
Tariff exemptions for imported bifacial panels: The last presidential administration applied tariffs to imported solar panels to stimulate the U.S. solar industry. The current administration, though, exempted imported bifacial panels from the tariffs. The National Renewable Energy Laboratory (NREL) considers this change in policy a major factor in making bifacial solar panels more affordable.
Turns shade structures and carports into solar arrays: Homeowners considering a carport or shade structure can use bifacial solar panels as roofing materials. This works best if the ground nearby has a high albedo, like a concrete driveway.
Current technology: Bifacial solar panels are readily available, unlike emerging technologies such as perovskite solar panels.
Bifacial Solar Module Cons
Higher cost: Bifacial solar panels are likely to cost more for two reasons. One is that the individual panels are more expensive. The second is that capturing the maximum amount of sunlight may require a solar tracking system.
Not well-suited for roof-mounting: Bifacial solar panels work best when there’s a considerable gap between the panels and the mounting surface. Most roof-mounted panels have a gap of just a few inches, plus many houses have roofs with a low albedo. Few homeowners choose ground-mount solar panels, which is how most bifacial arrays are installed.
Larger inverter need: An array that produces more power may need a larger inverter or more microinverters to transform Alternating Current (AC) into Direct Current (DC).
The Bottom Line: Bifacial Solar Panels Work Best In Certain Situations
Bifacial solar panels are a smart way to produce more power in the same physical footprint as a conventional solar module. Ultimately, though, the characteristics of bifacial solar panels may not align with the needs of most homeowners – who are more likely to benefit from monofacial panels.
Increased efficiency is an ongoing priority for the solar industry, and many innovations are on the horizon. Be sure to explore what homeowners can expect for the future of solar energy.