Bifacial Solar Panels in Snow: Surprising Power Gains

When snow covers the ground, most solar panels see their output plummet. But what about bifacial panels designed to capture light from both sides? I put two bifacial solar panels to the test in a snowy backyard, and the results were truly impressive.

What I Built

My setup for this experiment included two distinct bifacial solar panels. The first was a large, full-sized residential panel, rated at 370 watts. The second was a smaller, 200-watt Callsun N-Type TOPCon Bifacial Solar Panel, which I sourced from Amazon. Both panels were set up in my backyard, angled to catch the sun, with a fresh blanket of snow on the ground to provide maximum reflection. I used an Anker Solix F2000 portable power station to measure the power input from each panel.

Why It Works

Bifacial solar panels are designed with solar cells on both their front and back surfaces. This allows them to capture not only direct sunlight but also reflected light from surfaces like snow, light-colored roofs, or even the ground itself. Snow is an especially effective reflector, boasting an albedo (reflectivity) of up to 80-90%. This additional reflected light hitting the rear of the panel significantly boosts overall power generation. Another factor is temperature. Solar panels generally perform more efficiently in cooler temperatures. While the sun was out and bright, the ambient air was cold, which further enhanced the panels' ability to convert sunlight into electricity, even if the open-circuit voltage (VOC) might be slightly lower once the panel warms up.

Parts & Specs

• Residential Bifacial Solar Panel:
  • Module Type: DNA-120-BF26-370W
  • Max Power (at STC): 370W
  • Open-Circuit Voltage (VOC): 41.4V
• Callsun N-Type TOPCon Bifacial Solar Panel:
  • Model: Callsun-DB200W
  • Max Power (at STC): 200W
  • Open-Circuit Voltage (VOC): 27.31V
• Portable Power Station: Anker Solix F2000
• Stands: Adjustable, telescoping stands (for the 370W panel)

Math & Run-Time Numbers

First, testing the **370W bifacial panel with snow**: The open-circuit voltage (VOC) measured around 39.33V. When connected to the Anker Solix F2000, the input power fluctuated between 360W and 393W. This was very impressive, as it often exceeded the panel's rated 370W output due to the bifacial gain from the snow.

Next, the **200W Callsun bifacial panel with snow**: The VOC measured an impressive 29.78V, which was actually *over* its rated 27.31V. When hooked up to the power station, it consistently delivered around 232W. That's 32 watts over its rated capacity, a truly excellent performance.

For comparison, I cleared the snow from under the **370W panel**: The VOC dropped slightly to 38.57V. The power input to the Anker Solix F2000 then ranged between 332W and 373W. While still decent, it didn't reach the consistent high outputs seen with the snow, confirming the snow's beneficial effect.

Similarly, the **200W Callsun panel without snow** measured a VOC of 27.95V, still slightly above spec, and an input of 220W. This showed a loss of about 10 watts compared to the snowy conditions, but still delivered over its rated output.

Pros & Cons

Pros:

• Significant power boost in snowy conditions due to reflected light.
• Both panels, especially the Callsun, demonstrated excellent performance, often exceeding their rated wattage.
• Adjustable stands for the larger panel offer great flexibility in angling and positioning, maximizing sun exposure and reflection.
• Smaller bifacial panels are incredibly powerful for their size and can be a good option for portable setups like RVs.

Cons:

• Higher VOC in cold, bright conditions can be a concern for charge controllers if not properly managed.
• Full-sized residential panels, while adaptable with stands, are not truly portable for easy transport.
• Shipping costs for large solar panels can be prohibitive, making local pickup or pallet purchases more economical.

When To Use This vs. Alternatives

If you live in a region with regular snowfall, bifacial solar panels are a fantastic choice to maximize your energy harvest, even in winter. The extra reflection from snow can turn what might otherwise be a low-production period into a highly efficient one. Adjustable stands are key here, allowing you to optimize the panel's angle to capture both direct and reflected light.

For those looking for a more "portable" solution for an RV or off-grid cabin, the smaller Callsun-style bifacial panels offer incredible performance for their footprint. They're easy to deploy and can provide substantial power without permanent installation. However, always be mindful of the VOC, especially in cold weather, to avoid damaging your charge controller.

For homeowners and tinkerers who want to build a significant solar array without pouring concrete footings or dealing with permanent roof installations, flexible ground-mount options with bifacial panels can be a perfect fit. If you're buying large panels, consider checking local suppliers like Payoff Solar (mentioned in the video) to avoid high shipping costs, or look for deals on Amazon for smaller units.

Bottom Line

The tests clearly demonstrate that bifacial solar panels, particularly when combined with reflective surfaces like snow, can deliver exceptional power output, often surpassing their nominal ratings. This technology offers a compelling advantage for anyone seeking to maximize solar energy production, especially in colder, sunnier climates. The Callsun panel, in particular, proved to be an outstanding performer for its size and accessibility.

Final Wrap-Up

I certainly learned something new today, and I hope you did too. If you found this information valuable, please consider doing the five free things: like, comment, share, subscribe, and hit the notification bell. These metrics help push my videos to a wider audience, allowing me to continue bringing you more educational and testing-focused content. You can also book a one-on-one video consultation with me or submit a guaranteed-to-be-answered question through the links in the description. Stay safe, and we'll catch you all next time!