Bifacial Solar Panels: How They Work and When They’re Worth It

Updated October 2026.

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Bifacial panels have gone from a niche product to the standard on large solar farms. Now homeowners and businesses ask us whether they’re worth it on their own projects. The honest answer is that it depends almost entirely on how the panels are mounted. Here is how they work, what real-world tests show, and why Minnesota, Wisconsin and Iowa winters can work in their favor.

How bifacial solar panels work

A standard (monofacial) panel has solar cells behind glass on the front and an opaque backsheet on the back. A bifacial panel uses cells that can make power from both sides, with clear glass or a clear backsheet on the back. Sunlight hits the front as usual, and light that bounces off the ground, snow or a roof reaches the back.

How well the back side works is called bifaciality. A bifaciality of 80% means the back produces 80% of what the front would under the same light. In independent testing by Kiwa PVEL, average bifaciality was about 69% for PERC panels, 75% for TOPCon and 87% for heterojunction (HJT). PVEL also found that none of the 50-plus TOPCon designs it tested reached the 80% printed on most datasheets, so treat spec-sheet numbers as a best case.

One thing that confuses buyers: some panels use bifacial cells but have a solid backsheet, so they only collect light from the front. A panel is only bifacial if light can actually reach the back.

How much extra power do bifacial panels make?

The gain comes from reflected light, so three things decide it:

• What’s under the panels. Surfaces reflect different shares of sunlight (called albedo). Grass reflects about 15 to 25%, concrete about 25 to 35%, and fresh snow about 80%.
• Height above the surface. More space behind the panel lets more light in. Panels close to a roof get very little.
• Racking and spacing. Rails and frames behind the panel block light. Wider row spacing and trackers help.

Here is what field studies have measured:

Why snow helps bifacial panels

Snow is the Midwest’s built-in reflector. A field of fresh snow bounces back roughly four times more light than summer grass, and that light lands on the back of a bifacial panel just when days are shortest.

Snow also slides off bifacial panels faster. In the Ontario study, standard panels lost about 16% of their yearly output to snow cover, while bifacial panels in the worst case lost about 2%. Researchers in Vermont saw the same pattern: light reaching the back warms the panel slightly and helps snow slide off, especially on steeper, frameless panels.

For a farm, acreage or business with room for a ground mount, that winter boost is the best argument for bifacial panels in our region.

Where bifacial panels make sense (and where they don’t)

Good fits

• Ground mounts on farms and acreages, especially over gravel or with winter snow cover. We install many residential ground mounts and barn-mounted systems in the 40 to 60 kW range across the Midwest.
• Solar carports, canopies and pergolas, where light reflects off pavement or concrete and the open structure lets it reach the panels. See our solar canopy installation work.
• Trackers, which raise panels high and follow the sun. Nearly all new US utility-scale solar uses single-axis trackers, and most of those use bifacial panels.
• Commercial flat roofs with a white membrane, when the panels sit on tilted racking with space underneath. Expect the gain to drop as the roof gets dirty, so plan on keeping the membrane clean.
• Agrivoltaics, where panels are raised high above crops or pollinator plantings.

Usually not worth paying extra for

• Flush-mounted residential roofs. With only a few inches of space and a dark shingle roof behind them, bifacial panels gain very little. Here, panel efficiency, warranty and price matter more.

Durability, weight and warranties

Many bifacial panels use glass on both sides (glass-glass). That protects the cells from moisture and cracking and often comes with a longer performance warranty, commonly 30 years. A few tradeoffs:

• Weight. Large glass-glass commercial panels can weigh 75 to 85 pounds each, so racking and roof loads need to be checked. Some bifacial panels use a clear backsheet instead of rear glass, which saves weight.
• Thin glass. Kiwa PVEL’s testing found glass-glass panels with thin 2.0 mm glass broke more often in hail and load tests than panels with thicker front glass. In hail country, ask about glass thickness and hail ratings.
• Warranty examples. Qcells’ Q.PEAK DUO XL bifacial panel carries a 30-year performance warranty (at least 84.95% of rated power at year 30). Silfab’s bifacial SIL-590 XM+ carries a 30-year performance warranty (at least 89.3% at year 30).

For more on how long panels last in general, read our guide on how long solar panels last.

Do bifacial panels cost more?

The panels themselves usually cost only a little more than comparable standard panels, because most cells made today are already bifacial. The real cost difference is in the mounting: getting light behind the panels means taller racking, wider spacing or a tracker. On a ground mount or carport, that extra cost is often small next to the added production. On a flush roof mount, the gain is too small to justify paying a premium.

Bifacial vs. monofacial: quick comparison

Thinking about bifacial panels for your project?

Wolf River Electric designs and installs residential and commercial solar across Minnesota, Wisconsin, Iowa, Illinois, North Dakota and South Dakota, including ground mounts, barn mounts, carports and commercial roofs. We’ll tell you plainly whether bifacial panels will pay off for your site or whether a standard panel is the better buy. Get a free quote, or learn about our commercial solar work.

Frequently asked questions

Are bifacial solar panels worth it for a house?

On a typical flush-mounted roof, usually not as a reason to pay more. The back side gets little light, so the gain is often 2 to 4%. On a ground mount, pergola or carport at your home, they can be worth it.

Do bifacial panels work in winter?

Yes, and often better than standard panels. Snow reflects about 80% of sunlight onto the back side, and bifacial panels tend to shed snow faster.

How high should bifacial panels be mounted?

Higher is better, within reason. Panels raised a few feet above the ground, on a carport or on a tracker collect far more rear-side light than panels a few inches off a roof.

Do bifacial panels need a special inverter?

No special type, but the inverter and wiring must be sized for the extra current the panels can produce on bright, snowy days. Your installer should account for this in the design.

How long do bifacial solar panels last?

About as long as or longer than standard panels. Glass-glass bifacial panels often carry 30-year performance warranties.

Sources

• Kiwa PVEL 2024 Module Reliability Scorecard: bifaciality results
• Sandia National Laboratories PV Performance Modeling: albedo
• NREL: bifacial PV field performance on single-axis trackers
• Burnham et al.: bifacial performance in a snowy climate (Vermont), IEEE PVSC 2019
• Hayibo et al.: monofacial vs. bifacial snow losses (Ontario), Renewable Energy 2022
• Politecnico di Milano: bifacial gain at low mounting height (2024)
• Muehleisen et al.: bifacial panels on a white flat roof (2021)
• Kiwa PVEL: hail stress testing
• Qcells Q.PEAK DUO XL bifacial datasheet
• Berkeley Lab: Utility-Scale Solar 2025 edition

More from Wolf River Electric: home battery backup, Generac standby generators and solar panel removal and reinstall when you need a new roof.