Ontario's electricity demand is shifting in a way that makes winter performance a pressing concern when it comes to solar. Solar panel performance during winter is something many wonder about, and the answer isn’t as clear as you think. Keep reading to find out how solar works in winter and how it may actually help offset winter electricity demand.
Does Solar Actually Work in Winter?
Yes, contrary to popular belief, solar panels do work in the winter. Solar panels are rated for peak performance at 25°C, however they actually gain efficiency in colder temperatures rather than losing it. Heat is actually what reduces panel performance, not cold.
That efficiency gain doesn't fully offset shorter days and lower sun angles, though, so total winter output is still lower than summer output. For southern Ontario, winter production typically runs in the range of 30-40% of summer peak output, but that’s far from the misconception that solar panels basically shut down during winter.
What Affects Winter Solar Output Specifically
Two factors have the biggest impact on solar production in Ontario:
Daylight Hours
Winter days are shorter, which means fewer hours of sunlight for solar panels to generate electricity. Better cold-weather performance can help, but it can't make up for the reduced daylight hours.
Snow Cover
Snow can temporarily reduce or stop solar production while it covers the panels, but system design plays a big role in minimizing the impact. Steeper panels and elevated systems like trackers and solar carports tend to shed snow more easily, while low-tilt rooftop systems can hold it longer.
Panel technology matters too. VCT Group uses bifacial panels as a standard on its projects. Unlike traditional panels, which have an opaque backsheet, bifacial panels use transparent materials such as double glass on the rear side, allowing them to generate electricity from both the front and back. The front captures direct and diffuse sunlight, while the rear absorbs light reflected off the surface below, known as albedo.
Snow is one of the most reflective ground surfaces, which makes this especially valuable in Ontario winters. On elevated systems like solar carports and trackers, the rear side has more room to capture that reflected light, so even when the top of a panel is covered, the underside can keep producing. The effect is much smaller on rooftop systems, where panels sit close to the roof surface.
The takeaway: Ontario's winters don't automatically make solar inefficient. The right combination of system type and panel technology can make a meaningful difference in how well an installation performs through snow and shorter daylight.
How Solar Carports Perform in Ontario Winters
Solar carports are well suited to Ontario's climate. Their elevated design sheds snow more easily than low-tilt rooftop arrays, and with bifacial panels, the underside can keep capturing light reflected off snow-covered ground even when the top surface is covered.
VCT Group's Heliostation™ solar carports were designed and engineered for harsh Ontario winters. Each canopy includes a patented rain, ice, and snow management system as standard and is built to withstand temperatures down to -30°C. For snow-heavy sites, the pitched apex configuration is designed to manage snow load and optimize power generation year-round.
The benefits go beyond energy. A Heliostation turns an underused parking lot into a power plant while protecting what's underneath. Vehicles, inventory, and people are sheltered from snow, rain, and hail, which means no clearing cars on winter mornings and less wear on vehicles and parking surfaces over time.
Ontario's Winter Electricity Demand: Why It Matters Now (And Will Matter More Later)
2025 saw Ontario's highest electricity demand peak in 12 years, mostly thanks to a plethora of summer heat waves. Ontario is a summer-peaking system, meaning electricity demand is typically at its highest during the summer. However, it might not always be that way, and many predict that change will come sooner than later.
The Independent Electricity System Operator (IESO)'s own long-term planning forecasts that Ontario will shift to a dual-peaking system by the early 2030s, with winter demand eventually rivaling summer demand.
The rise of winter electricity demand can be attributed to the higher use of electricity-based heating systems, especially in metropolitan areas like Toronto. Additionally, EV charging tends to increase during the winter, adding load to a season that historically saw far less strain.
That shift matters for how commercial property owners think about on-site solar generation. A system evaluated only on its summer output is being evaluated against yesterday's demand pattern, not the one Ontario's own grid planners expect over the system's operating life.
How On-Site Generation Still Helps During Winter Demand Peaks
Even at reduced winter output, on-site solar is still offsetting consumption during the winter season. As winter demand climbs toward matching summer demand over the next several years, generation that reduces draw from the grid during that period becomes more valuable, not less, even if the raw output number is lower.
This is the same logic behind evaluating a solar investment on total annual value rather than peak-month output alone: a system that performs strongly for eight months and moderately for four is still offsetting real consumption across winter.
Designing a System That Accounts for Ontario's Winter Conditions
The gap between a system that handles Ontario winters well and one that doesn't comes down to design choices made before installation. Panel tilt and orientation affect how much snow naturally sheds, and inverter and system sizing should account for the real seasonal range a property will see, not just the summer average.
Curious what your property would actually produce across all four seasons?
Start with a site assessment. At VCT Group, we specialize in delivering solar array designs curated to your local climate and property’s energy needs, so you can make the most of your solar investment. We'll model your property's real seasonal output, including how it performs through an Ontario winter.