If you knew there was a solar panel system for your home that delivered up to 50% more solar power compared to conventional solar panels, would you be interested? Then look no further than bifacial solar panels.
Industry insiders predict that the market for bifacials will increase tenfold in the next four years. The primary reason is that production costs are becoming competitive with those of the industry standard: monofacial solar panels.
This statistic represents a veritable explosion in solar technology since bifacial solar panels hit the market only about a decade ago.
In this article, you’ll learn everything you need to know about bifacial solar panels. Included is information on the companies spearheading this solar energy technology and how to purchase their bifacial solar products for your home solar energy project.
At the end, there’s a checklist to determine if bifacial solar panels are right for you.
What is a bifacial solar panel?
A bifacial solar panel is a double-sided energy factory that transforms sunlight into electrical energy on both its top and bottom sides. They are different from monofacial solar panels which only use one side for solar energy production. The word bifacial comes from the prefix “bi-” (meaning two), and “facial” (for face).
Bifacials are equipped with solar cells on both the top and the rear of the panel. They are usually monocrystalline, although polycrystalline can be used. Because they are slim, they resemble thin-film panels. Bifacial solar panels are frequently frameless, too.
The top of each solar module is covered in protective glass. The flipside may be glass or a clear backsheet. This is different from conventional solar panel systems with opaque backings.
Here is a diagram of a side view of a bifacial solar panel:
The hardware used to mount a bifacial solar array is designed to minimize shading. This means there are only very narrow support rails and corner-only vertical supports.
The typically backside-placed junction box─the electronic guts and brain of your solar panel system─is smaller than in traditional solar arrays. So, it takes up less space and casts less shade on the back solar cells. The result? More solar power for you.
How does a bifacial solar panel work?
The top solar cells of a bifacial solar panel system face the sun, so they capture incident sun rays directly, absorbing only certain wavelengths. The top solar cells function like those of a conventional solar panel array.
The bottom solar cells absorb light that is reflected off the ground. This light is called albedo light. White or light colors reflect better than dark colors. Painting a white or silver surface on a roof or concrete driveway under the panels provides the same effect, too. Studies show that a white surface reflects more than 80% of albedo light. (Grass, by comparison: 23%).
To optimize the operation of the underside cells, using superior silicon in monocrystalline cells is preferable.
Unlike monofacial solar panel systems that are placed in racks parallel to a surface such as a rooftop, bifacials produce more energy when they are angled off of the roof or ground at varying degrees.
In these types of titled installations, there is a great amount of reflection. Because sunlight bounces off of all objects reflectively at many different angles, bifacial solar panels are better able to capture more of it. They are even productive on cloudy days when monofacial solar cells are at a greater disadvantage.
There are other installation setups that capitalize on the earth’s daily rotation in relation to the sun. To produce two energy peaks throughout the day, half of the bifacials in an array can be tilted toward the east to capture sunrise and morning rays; the second half, to the west, to soak up afternoon intensity and sunset rays.
Another installation alternative places bifacials vertically. This arrangement will also have a double peak each day. During each peak, the reflection of sunlight on the other side of the solar panels will also contribute to energy production. An advantage of a vertical system is that snow or sand blown over in weather events won’t block its functioning.
Due to glass covers on both sides of bifacial solar panels, they are more durable than conventional solar panel systems. As a result, warranties, in some cases, are typically 5+ years longer (that is, 30+ years versus 20–25 years).
Efficiency comparisons between bifacial and monofacial solar panels
Efficiency refers to how well a solar cell converts the total amount of solar energy impinging on its surface into electrical energy.
You may think that bifacial solar cells would exactly double the efficiency of a monofacial solar cell—since there are twice as many solar cell surfaces—but this is not yet the case.
A 2018 study by LONGi Solar showed that bifacials can increase efficiency by 11% compared to a conventional solar panel system.
The bifacial solar cell efficiency increase can be as high as 27% with a solar tracking system that tilts solar cells continuously toward the sun during its trajectory across the sky. This system maintains a perpendicular panel orientation toward the sun throughout the day for maximum direct exposure of the cells to radiant solar energy.
To achieve the same degree of solar power as a typical monofacial solar array, fewer bifacial solar panels are needed. As the bifacial solar panel price becomes competitive with monofacials, consumers searching for maximum efficiency with fewer panels, (because of limited space, for example), would do best by choosing bifacial solar panels.
Here’s a summary table that illustrates the differences in solar cell efficiencies between the major commercial options in solar power today.
|Type of Solar Panel||Total Solar Cell Efficiency|
|Monofacial Monocrystalline||18% +|
|Bifacial Monocrystalline||20% +|
Bifacial solar panel installations: Is it right for your home?
Residential applications of bifacial solar technology are also possible, but it depends on your:
- Goals for energy independence
Here’s an example of a pergola on a home in Oklahoma:
In this example, bifacials make a great awning for shade or rain/snow protection while slashing your electricity bill. Integrated into your home’s appearance, bifacial solar panels provide aesthetic—and functional—appeal.
Checklist for residential bifacial solar panels
If you’re considering a bifacial solar panel installation for your home, consider each of these questions before purchasing them. If you check off even one of them, a bifacial solar panel installation would work for you. If you select more than one, bifacials are for you!
- Are you considering a ground-mount solar system for your property?
- Is there snow cover on my property for a significant part of the year?
- Is there a sandy area on my property (desert, beach), or would I be willing to create a mini desert or mini beach on my property?
- Do I have or would I like to construct one or more pergolas (elongated or small) on my property?
- Do I have or would I like to add awnings around the outside of my home or above windows?
- Is my roof white or silver or could I paint it one of these colors or install a white or silver covering?
Because bifacial solar panels take up less space to provide the same amount of solar power as some conventional solar panel systems, you don’t need as much land, but you do need a light-colored surface for optimal performance.
Bifacial solar panel manufacturers
There are many bifacial solar panel makers around the world offering a wide variety of bifacial solar panels. For a great start locating bifacial solar panel manufacturers, check out this general directory. Here are some of the major ones and their products taken from that list.
- Amerisolar: based in California with modules made in the USA and in China; maker of bifacial solar panels; list of sales offices around the world
- Silfab Solar: North American manufacturer of bifacial solar panels committed to onsite sustainability and end-of-life recycling; contact Silfab to find local distributors
- Sunpreme: R&D located in California and production in China; can install a ground-mount system with 3 daily peaks; Sunpreme has several sales partners around the world
If you’re interested in the bifacial products of a specific manufacturer, the next step is to contact them about local availability. Sometimes, your local solar installer can special order them for your project if they don’t already carry them.
Major takeaways on residential bifacial solar panels
One of the newest solar power innovations─projected to grow exponentially in popularity in the next few years─is bifacial solar panels.
Bifacial panels have solar cells on both sides. The front captures incident sunlight while the back absorbs reflected light. More captured sunlight means greater solar cell efficiency compared with traditional solar arrays with only frontside solar cells.
Now competitively priced with conventional solar panel systems, bifacials deliver greater efficiency and can take up less space. Residential uses are most productive on light-colored surfaces. Bifacial solar panels work well as awnings or pergolas.
There are many manufacturers of bifacial solar panels all over the world, contributing to the renewable energy revolution. comment