Bifacial solar panels: What you need to know

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 faces. This design creates an interesting new solar solution for certain types of installations.

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- instead, these types of panels have solar cells on both sides. This enables the panels to absorb light from the back and 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 modules can be effective in residential applications like pergolas and ground-mounted systems. But, for the majority of property owners considering a rooftop installation, bifacial panels don't make sense – bifacial modules 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.

The majority of solar panels are monofacial. This means they have one photovoltaic side, which can absorb light from the sun and convert it into energy. Bifacial solar panels can absorb light on both sides and require less space.

Because bifacial panels have more surface area to absorb sunlight, they are more efficient than traditional panels. If bifacial modules are set up vertically, they can capture energy at two of the sun's peak times: sunrise and sunset. Vertically set-up panels are also more resistant to weather like snow & sun that could cover a panel and block some of its efficiency. Bifacial solar panels are also more durable than traditional panels.

Despite some advantages, there are also many reasons that monofacial panels could still be better for you than bifacial solar panels. Because bifacial panels are so unique, they often require additional work and equipment. Despite their higher efficiency ratings, they may cost more for homeowners because of things like ground mounts required for vertically mounted panels. There are also additional needs like solar tracking systems, which are necessary.

Compared to traditional panels, there are relatively few manufacturers of bifacial panels. Here is a list of some of our favorites.

Hyundai Energy Solutions

Hyundai is a large and trustworthy manufacturer of panels and other equipment worldwide. They have an extensive offering of bifacial panels, including the GI Series. They have an average power of 2.5-2.7W per cell and around 19% efficiency.

LG Solar Panels

LG Solar Panels manufacture some of the market's highest-rated and most efficient solar panels. One of their most popular offerings is the LG NeON2 BiFacial series of panels. They have an average power of 5.6W per cell and 19.5% efficiency.

Jinko Solar

Jinko Solar is known for its low-cost offering of solar panels. Their Tiger Bifacial series has an average power of 3W per cell and are 20% efficient on average.

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 also exist. One of the most noticeable physical traits of bifacial panels is their slim profile - many bifacial plans 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 back sheet.

The design of bifacial solar panel mounting systems is also different from traditional solutions. Bifacial panels need the least amount of shaded space possible to capture the most energy 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.

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 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 can potentially 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 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 up to the bifacial panels. Generally, lighter-colored surfaces like sand will lead to more reflected sunlight than darker surfaces like asphalt or dirt.

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

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 and generate 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 reflected light to reach the back of the panels.

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 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.

Tariffs on solar panels and equipment have affected the industry in the last few years. Starting in 2018, President Trump leveled tariffs on solar panels produced non-domestically. These tariffs were intended to spur US solar manufacturing and production industry growth—this limited access to cheaper solar panels.

Since taking over the presidency, the Biden administration has maintained these tariffs, deciding to extend them for an additional four years in 2022. They made a crucial decision, however, in choosing to exempt bifacial solar panels. This is extremely important for consumers in that it allows you to have access to cheaper panels.

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. Their higher cost from additional required equipment means that average homeowners would still probably be paying more to install bifacial panels when compared to the amount they save from their increased efficiency. Regardless of project size, geography, or other factors, comparing multiple quotes is the best way to get a good deal on a solar panel installation. 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, make a note in your profile so installers can provide a quote based on your preferences.