Bifacial Solar Panels: How You Catch Sunlight From Different Directions

Solar panels generally rely on energy coming directly from the sun. But some panels can generate electricity from rays after they bounce off the ground.

Bifacial solar panels, the reversible fashion accessory of the solar industry, are double-sided panels that absorb solar energy from both sides. Tests by solar manufacturers have found these panels can generate 11% to 23% more energy than their monofacial or single-sided counterparts.

However, just because bifacial solar panels provide greater utility doesn't mean you can contact your local installer and have them mount one on your roof. These panels function best when installed at ground level, absorbing sunlight reflected off the Earth's surface. While an 11% to 23% increase in electricity output may seem small, this incremental gain can significantly accumulate over time. 

If you have ample acreage, and your roof doesn't face south (the optimal direction for solar panels in the US), you might want to consider using bifacial panels. Here's everything you need to know about bifacial solar panels.

How do bifacial panels work?

Sunlight reflects, to varying degrees, off everything. If you've ever been outside after dark when there's snow on the ground, you've probably noticed how much lighter it is than without snow. This effect even has climate change implications. Research shows ice reflects about 85% of sunlight, but open water reflects only 7%. As Arctic ice melts, the water underneath absorbs more light (and heat). 

All of that is to say, there's enough light bouncing around for solar panels to generate electricity on both sides.

Bifacial solar panels operate similarly to the traditional one-sided monofacial solar panels, said Jake Edie, an adjunct professor at the University of Illinois Chicago. Edie teaches a course on clean energy in the electric grid. The key difference is with the design. Edie explains that instead of having an opaque back, bifacial solar panels feature a transparent backside. This feature allows them to absorb solar energy from both sides, he said.  

Considering Solar Panels?

Our email course will walk you through how to go solar

 

Bifacial panels are generally best suited to utility-scale and commercial solar installations or buildings with flat rooftops, Edie said.

Standard installation methods don't allow sufficient light to reach the backside of the panels on a residential rooftop. This minimizes the additional benefits that bifacial panels can offer, Edie said. Panels installed on flat rooftops or ground-mounted systems, Edie says, can take full advantage of the light reflected off the ground, making bifacial solar panels a preferred choice in these scenarios.

Considering Solar Panels?

Our email course will walk you through how to go solar

 

Bifacial panels can work at home

Bifacial panels, while more expensive than other solar panel options, are attractive for certain homes under the right circumstances. Homeowners often prefer them in situations where it doesn't make sense to have a solar panel mounted on a roof. In areas with frequent dense snowfall or arid desert conditions, ground-mounted bifacial installations can take maximum advantage of the sunlight reflecting off the ground. 

Moreover, if you're considering constructing an outdoor covering like a pergola or awning, you can integrate bifacial solar panels into the design. The open space beneath these structures allows the reflected light to reach the panel's rear side, enhancing its utility. 

How can I get bifacial solar panels?

The process is similar to getting traditional solar panels. Many solar panel manufacturers in the US, including SunPower and Longi Solar, offer bifacial solar panels. Consult with a solar panel installer or provider to ensure that bifacial panels fit your requirements and installation site. 

How are bifacial solar modules installed?

Bifacial solar panels are installed in the same way monofacial panels are installed. However, because of their unique design, homeowners are advised to install them on elevated racking systems to allow light to hit the back of the panels. This method is handy for ground-mounted systems and flat commercial rooftops.

Bifacial solar panels vs. monofacial solar panels

Both bifacial and monofacial solar panels offer distinct benefits:

Bifacial solar panels in commercial and utility-scale applications

Bifacial solar panels are gaining popularity in commercial and utility-scale applications due to their increased efficiency in generating solar energy, Edie said. These include installations on flat commercial rooftops and vast fields with acres of solar panels. They are particularly useful in utility-scale solar installations where the panels are mounted directly into the ground, allowing for ample light reflection. Surfaces like sand and snow will reflect more sunlight than darker surfaces like asphalt.

Bifacial solar panel FAQs

Correction, Aug 18: This story originally presented some statements as direct quotations that were actually paraphrases of what the individual cited had said. Those passages have now been rendered appropriately as paraphrases.