Alberta solar yields 1,309 kWh/kW, beating European model predictions

Firefly Solar has analyzed real-time, panel-by-panel performance data from more than 4,100 home solar systems, according to pv magazine. The company says the analysis focused on a clean sample of 573 Alberta systems that maintained an uninterrupted monthly record for all of 2025.

The company reports that the average rooftop system in this sample generated 1,309 kWh of electricity for every kilowatt of installed panels.

Performance vs. Models

According to Firefly Solar’s records, the majority of installations in Alberta yielded outputs ranging from 1,170 to 1,469 kWh/kW, situated on rooftops oriented toward the south, east, or west. These figures surpass the European Commission’s PVGIS estimates for optimally tilted, south-aligned roofs in Frankfurt (1,030 kWh/kW) and London (972 kWh/kW). As a result, standard Alberta rooftops delivered roughly 25% greater energy production than the optimal German scenario. The firm credits this additional yield to the region’s significant altitude, arid atmosphere, and extended daylight hours during summer.

The collected data is concentrated largely in Alberta, supplemented by smaller cohorts from Nova Scotia, British Columbia, and New Brunswick. Between January and August 2026, an average Alberta system recorded 987 kWh/kW. Over that identical timeframe, a typical Nova Scotia installation generated 773 kWh/kW. This disparity results in a 28% difference in performance between the two provinces.

Winter Resilience

From January 31 to February 19, 2025, Calgary endured a harsh cold snap where daytime temperatures fell to −24.5 C and new snowfall occurred on most days. Cold weather typically boosts solar panel efficiency. However, during the peak freeze period from February 4 to 19, the average system in Firefly’s data yielded only 0.04 to 0.14 kWh per kilowatt per day. By February 5, 88% of these systems were generating under 0.1 kWh per day.

A Chinook wind, a warm, dry air mass moving down from the Rockies, raised Calgary’s daytime high from −17 C to 3.7 C overnight. As snow slid off the panels, typical system output rebounded to over 4 kWh per kilowatt per day within three days. This figure is roughly two-thirds of what a standard June day produces.

In the frozen February 2025, these systems averaged 35 kWh per kilowatt. In February 2026, the identical group averaged 63 kWh per kilowatt. This gap equates to approximately 29 kWh per kilowatt lost, or about 2% of the annual total.

Seasonality and Calculators

Canadian solar generation is heavily skewed toward summer. In 2025, the four-month winter period from November to February contributed just 9.8% of total annual fleet power, while the four months from May to August accounted for 54%. This disparity is stark at the individual system level: a typical installation generated only 17 kWh/kW in December but produced 186 kWh/kW in June.

Metric	Value
Winter output share (Nov–Feb)	9.8%
Summer output share (May–Aug)	54%
Typical December generation	17 kWh/kW
Typical June generation	186 kWh/kW

Standard solar calculators often miss this because they don’t account for snow. While tools like PVGIS predict a Calgary roof will produce between 14% and 21% of its yearly power during winter, these estimates can be far too optimistic. A calculator may arrive at an accurate annual total while significantly overestimating winter months. From January to August, 533 systems made within 2% of the same kWh/kW in 2025 and 2026, even though individual months swung by as much as 84%.

Market Context

• Canada’s trade tribunal scrapped extra import taxes on Chinese solar panels that had been charged since 2015.
• The United States is adding tariffs reaching up the supply chain to polysilicon.
• Installers in both countries are now buying equipment under completely different rules for the first time in a decade.
• The federal Greener Homes program, which helped put solar on more than 50,000 homes, wound down in October 2025.
• From January to August 2026, the number of new systems connected to monitoring was 39% higher than in the same months of 2025.

The removal of the Canadian import tariff reduces costs, though not every panel will get cheaper overnight. Some savings are absorbed before reaching customers, and panels represent only part of the total system price, with labor, permits, sales, and financing making up the rest. For residential solar, the earlier end of the Greener Homes program was a bigger shakeup than the current trade shift. Being honest with homeowners about winter output—such as explaining that a system will make about 10% of its June output in December—helps manage expectations. Panel-level monitoring also allows installers to distinguish weather-related dips from actual equipment failures; if all systems dip simultaneously and recover on the first warm day, it is snow, whereas a single system remaining offline after a thaw indicates a need for maintenance. With tariffs gone, well-built systems on the prairies may soon cost less to install, and winter is just part of the plan.