bifacial solar panels

Bifacial solar panels: what you need to know

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A new product trend is emerging in the solar industry. Bifacial solar panels are solar panels that can capture sunlight on both their front and back and are an interesting new solar solution for certain types of solar installations.

What are bifacial solar panels?

Traditional (monofacial) solar panels capture sunlight on one light-absorbing side, and light energy that cannot be captured is reflected away. This is not the case with bifacial solar panels- rather, these types of panels have solar cells on both sides. This enables the panels to absorb light from the back as well as the front. Practically speaking, this means that a bifacial solar panel can absorb light that is reflected off the ground or another material.

Bifacial solar panels can be effective in certain residential applications like pergolas and some ground-mounted systems. But, for the majority of property owners considering a rooftop installation, bifacial panels doesn’t make sense – bifacial panels are best used in commercial or utility-scale applications where panels are elevated and angled away from a mounting surface, allowing light to reflect into the back of the panel.

Bifacial solar panel design

A bifacial solar panel looks significantly different than a traditional monocrystalline or polycrystalline silicon panel. Bifacial panels are usually made from monocrystalline cells, but polycrystalline designs exist as well. One of the most noticeable physical traits of bifacial panels is their slim profile – many bifacial designs call for limited framing, and the modules themselves are housed in a thin, transparent layer which can be a dual-glass design or made with a clear backsheet.

ground mounted bifacial solar panels
Ground-mounted bifacial solar panel array

The design of mounting systems for bifacial solar panels is also different than traditional solutions. In order to capture the most energy, bifacial panels need the least amount of shaded space possible on the front and back of their surfaces. New racking solutions for bifacial panels can utilize small junction boxes, narrower support rails, and vertical supports only at the very corners of the racking system to reduce shading on the backside of modules.

Bifacial solar panels for commercial and utility-scale applications

The ideal use case for bifacial solar panels is in commercial and utility-scale solar installations, especially those that utilize solar trackers. In a study conducted by LONGi, a solar panel manufacturer, bifacial panels yielded 11 percent more energy than standard solar panels in a tilted, ground-mounted solar installation in China. More impressively, a system using bifacial panels paired with solar trackers yielded 27 percent more solar energy than a similarly sized system using traditional panels.

Bifacial panels have the potential to boost energy output for large-scale solar installations due to their ability to absorb energy on both sides. When a solar panel is mounted above the ground, as is the case in most commercial systems, sunlight that strikes the ground beneath the panel is reflected up and can be absorbed by back-facing solar cells. Additionally, depending on the surface below, more or less light will be reflected back up to the bifacial panels. Generally, lighter colored surfaces like sand will lead to more reflected sunlight than darker surfaces like asphalt or dirt.

Can you use bifacial solar panels for residential installations?

In general, bifacial solar panels are not best suited for residential rooftop solar installations. Given their likely price premium when compared to traditional monocrystalline or polycrystalline panels, they make the most sense for larger solar projects that allow for reflected light to easily reach the back of the panels.

While bifacial panels are best suited for commercial or utility-scale solar installations, they can be used in select residential cases. Free-standing structures like pergolas can benefit from bifacial panels, which will provide partial shade in addition to generating energy. Bifacial panels can also be used in any other case where there is nothing directly behind the solar panels. For example, awnings and canopies made from bifacial solar panels allow for reflected light to reach the back of the panels.

solar pergola with bifacial solar panels
A solar pergola made with bifacial panels; project by Alternative Energy Southeast

If you’re considering a ground-mounted solar system instead of a rooftop installation, bifacial panels may be suitable for you as well. Similar to in commercial and utility applications, a residential ground-mounted system is propped up above the ground, allowing for light to reach the backside of bifacial panels.

Find the right solar panels for your installation

Bifacial solar panels may be worthwhile for commercial and utility solar developers, but they typically don’t make as much sense for residential rooftop projects. Regardless of project size, geography, or other factors, the best way to get a good deal on a solar panel installation is to compare multiple quotes. On the EnergySage Solar Marketplace, you can register your property for free and begin receiving solar quotes from high-quality, pre-screened installers in your area. If you are interested in bifacial solar panels, simply make a note in your profile so installers can provide a quote based on your preferences.

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About Jacob Marsh

Jacob is a researcher and content writer at EnergySage, where he focuses primarily on current issues–and new technology!–in the solar industry. With a background in environmental and geological science, Jacob brings an analytical perspective and passion for conservation to help solar shoppers make the right energy choices for their wallet and the environment. Outside of EnergySage, you can find him playing Ultimate Frisbee or learning a new, obscure board game.

8 thoughts on “Bifacial solar panels: what you need to know

  1. Aditya Kiran

    what happens when we keep junction box on backside where bifical cells comes, will it create hotspot
    please reply

    1. Artisanal PV

      In every bifacial panel I’ve seen, the junction box is pushed out to the very edge of the panel and is much thinner (think very long rectangle) than the square-ish box used on mono facial panels. The bifacial junction box pretty much only covers glass edge area. I’m not sure if there is a “hotspot”, but if there is it would be relatively small and probably wouldn’t have any effect on the panel or its performance.

  2. Steve C

    how would bifacial solar panels work on a boat? What if we placed them over our Davies for our dingy and during the day while the dingy is tied off the water reflects back up to the bottom side? Would that surpass the efficiency of traditional panels

  3. Stephen Cerro

    What would happen if you placed the bifacial panels on a residential rooftop that has a highly reflective angled roof or mirrored roof? Would the efficiency jump or would that be too much and burn out the cells?

    1. Artisanal PV

      I can visualize what you’re getting at, but having trouble putting it in to words. Bifacials absorb the reflected light on the downward facing side. Having greater surface area underneath the panel provides better irradiance back up away from the surface (ground diffusion), so to get best performance you don’t want to have the panel too close to whatever surface its resting on – closer to the surface, less diffuse light being reflected back up. Thus why not recommended for roofs. As for the heat issue, solar panels are less efficient the hotter they become, the suns heat has nothing to do with the energy produced rather the light itself (photons)…

  4. J F P L

    How do you estimate the efficiency for Bifacial Solar Panels?. I assume it is different than the traditional solar panels.

  5. madhu

    This article is so interesting! Bifacial solar panels may not be worthwhile for residential rooftop projects but are a great option for commercial projects. There are several companies that offer storable solar solution for residential projects as well. One of which is YouPower. The good news is they provide solar power at night! The Storable Solar System takes excess energy collected by your solar panels during the day and uses that excess energy to power home at night. This Storable Solar System lets customers “unplug” from the Utility company and their Time of Use pay schemes. Homeowners can use their own supply of energy to power their homes throughout the night and not have to worry about their electricity bill breaking the bank. Not only do our customers have the choice of how they can power their home but their Storable Solar System helps them save money every month on their electricity bill.


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