A common concern for potential solar buyers in northern climates is snow: how effective are solar panels when it's snowy, and will they be efficient enough during the winter to be worth the investment? In areas with significant snow accumulation and inclement weather throughout the winter months, it might seem like going solar isn't an option. However, with the wide range of sophisticated solar technologies on the market, even people in the snowiest of climates can make the change to solar energy for their home or business.
Solar Panels and Snow
It's true that snow can affect panel effectiveness, because the amount of energy a panel produces depends on the amount of light that is able to reach it. That means that if your panels are covered in snow, they won't be giving you the energy yield you can typically expect from your system. They will still be producing energy, just at a lower level than they would be otherwise. The key is to use a solar racking system that will maximize power production, even when it's snowy out.
Advantages of Dual-Axis Solar Trackers in the Snow
Snow removal is an issue for fixed systems because they're static, meaning that snow buildup is a frequent problem. Not only does the snow cover the panels and impede their function, they don't shed much snow on their own (although you can usually expect most panels to naturally shed some snow over the course of the day, this will typically only account for a small amount of snow buildup in a fixed system). You or your solar installer will need to clear the panels off every time it snows to ensure your system is producing energy, which takes time and energy.
On the other hand, because dual-axis solar trackers are always positioned at the optimal angle to the sun, panels warm up much faster than fixed systems and any snow buildup will melt more quickly. They're also tilted at a steeper angle than fixed arrays, so the panels can shed snow more easily, and their natural movement facilitates snow shedding. Typically, on the first sunny day after it snows, most snow buildup will completely melt and slide off the tracker on its own, meaning you won't experience any reduced energy production.
Unlike fixed systems, a tracker is also tall enough that any snow on the ground generally won't impede the system's function, both in terms of snow buildup on the panels and in terms of the movement of the panels. Some systems, like the AllEarth Solar Tracker, also come equipped with built-in snow mode functions to speed up the snow shedding process, meaning less downtime for your system.
Not only that, but because solar trackers follow the sun, they produce significantly more energy than fixed systems (up to 30% more than fixed ground-mount systems, and up to 45% more than roof-mount arrays). This means that even if the panels are covered by snow, you'll still be getting more energy out of your tracker than you would be getting out of a comparably-sized fixed system.
Solar Trackers in Action
45% more energy sounds like a lot, especially in the middle of winter. So to test out our claim, we did a side-by-side comparison of two systems, one roof-mount and one tracking, installed at a residence in Chagrin Falls, Ohio. Both systems had identical shading profiles, inverter selection, and module selection. Dealer partner Bold Alternatives collected a month's worth of data in January 2016, and the results speak for themselves: the 6.84kW solar tracker outperformed the 8.55kW roof-mount system by nearly double, producing 442kWh in one month versus the roof-mount's 228kWh.
Want to learn more about how well solar trackers perform in northern climates? Download the complete case study here.