Icy Interference: Investigating Snow's Effect on Solar Panels

Did you know over 43,000 buildings in Canada have solar panels? And we are the second snowiest country in the world. How much power is lost when snow covers panels in the winter? How much power could be gained by clearing those panels?

My home gets its energy from solar panels. I live in a neighbourhood called Treehouse Village Ecohousing, an environmentally-friendly housing community of 30 homes with 513 roof-mounted solar panels generating enough power (over the year) to supply all our energy needs. For energy resiliency, a back-up battery system in our community hall powers that building during grid outages.

In January 2026, a blizzard caused a major power outage. We depleted the community hall’s backup battery and wondered what could be done to replenish it. The panels were covered with snow; the battery-tied panels could not generate power. My neighbors asked, “Dylan, should we clear off the panels?”. It’s their question that inspired this project.

How does snow affect solar panel energy production? How much snowfall will reduce the power production to zero? Do cloud cover and temperature affect power production? When is it worth clearing snow from panels? Understanding these topics can help Canadians make informed decisions about whether to clear snow from solar panels.

I hypothesize that after 5cm of snow accumulation on the panels, production will drop to zero, on sunny days and on cloudy days. Additionally, I hypothesize that snow accumulation has more significant impact on power production than cloud coverage.

MATERIALS

Solar panels (4 x 440W)

Measuring stick (ruler and broom handle)

Snow brush

Snow shovel

Clipboard & recording sheet

PROCEDURE

Background research consulted several sources: scientific publications, interviews with topic experts, and internet search (see References).

Four equivalent panels were chosen based on their accessibility for clearing and their comparability. An ANOVA test demonstrated that panels A, B, C, and D generated equivalent power when completely clear (ANOVA p = 0.999). This validates the study design, in which any of the four panels could be used for clearing.

Observations were recorded on 38 occasions in varying weather conditions between January 18 and February 18, 2026. Measurements were taken when all four panels received unobstructed daylight, between 11:30AM and 3:45PM.

To measure the depth of snow accumulation without disturbance, a measuring device was constructed from a broomstick and a ruler.

Observations were recorded on a clipboard and transferred to a spreadsheet.

After measurements were conducted, panels A & D were cleared, providing a direct side-by-side comparison between panels with and without snow coverage.

Additional data were obtained from an external thermometer and a solar monitoring system

The data was used to calculate the theoretical maximum power production in 5-minute increments for each panel, and the value ($) of power generated

Graphs were produced to illustrate relationships between the variables.

CONTROLLED VARIABLES

There are many variables that could affect power generation on this solar array. The side-by-side experimental design was used to control many of these variables. Taking measurements immediately before and after clearing reduced the influence of cloud cover, time of day, date, and temperature on power production.

Hypothesis 1: Power Production vs. Snow Accumulation

The hypothesis that after 5cm of snow accumulation on the solar panels, the power production will drop to zero, was partially supported by the data.

Results shown in Figure 1 reveal that after 4.5cm of snow accumulation the power production dropped below 3% of the theoretical maximum for those dates and times.

Furthermore, the data shows that power production follows an exponential decay with increasing snow depth, not a linear relationship. The exponential fit (R² = 0.49) is better than the linear fit (R² = 0.363) - a power series fit is even better (R² = 0.841) except that power series cannot model zero snow as it would result in infinite power. This means that even a small amount of snow inhibits power production significantly. Figure 2 summarizes the average percent of maximum power for each depth range.

The side-by-side experimental design controlled for environmental variables and allowed for direct comparison. Cleared panels significantly outperformed snow-covered panels. When Panels A & D were clear and B & C had snow, cleared panels averaged 53.5% of theoretical max vs. 11.9% for snow-covered panels. Paired t-test: p = 0.0000036, Cohen's d = 1.58 (very large effect). See Figure 3 and Figure 4.

Some measurements show panels producing more than 100% of their theoretical maximum. This could be due to increased output efficiency at lower temperatures and/or the theoretical maximum calculation being slightly conservative.

Hypothesis 2: Snow Accumulation vs. Cloud Cover

The hypothesis that snow accumulation has a more significant impact on power production than cloud cover was partially supported by the data. The side-by-side design allowed for separation between the impact of snow accumulation and cloud cover. Both had impacts, though different relationships to power production.

Snow’s effect on power production is exponential. Even at 2-3 cm of accumulation, the power production drops to near zero and stays there no matter the additional accumulation. Cloud cover’s effect on power production is more linear. On the cloudiest days, panels still produce meaningful power. Cloud cover had a strong effect on clear-panel output (R² = 0.61: about 60% of the remaining variation in power is explained by cloud cover).

While both snow accumulation and clouds impact power production, snow accumulation at any real-world depths effectively eliminates production, while cloud cover only reduces it.

Temperature Influence

There is extensive research on the impact of temperature on solar panels; silicon panels lose about 0.3–0.5% efficiency per degree above 25°C, and gain some efficiency below it. In this study, temperature did not significantly affect panel output (R² = 0.038). It is likely that the variation in the observed temperature range (-12°C to +4°C) was insignificant compared with the substantial influence of snow accumulation and cloud cover.

Energy, Economic, and Environmental Analysis

The 33 panels studied in this array feed an 18.6 kWh backup battery located in the community hall. Every kilowatt hour produced at Treehouse Village by the solar panels saves $0.20 and 0.528 kg of eCO2. Figure 5 indicates the extra power generated by clearing single panels on select sunny days during the study period, the percent of backup battery capacity met by clearing those panels, and the money and emissions saved. It extrapolates those figures to an estimate for clearing all 33 panels.

To Clear or Not to Clear?

While this study’s hypothesis was initially focused on the impacts of snowfall and cloud cover on solar panel power production, it was found that a broader set of factors influenced real-world decision-making about snow clearing (Figure 6):

Accessibility

Financial savings

Greenhouse gas emission reduction

Availability of battery storage

Weather forecast

Guidance for Treehouse Village

The following factors justify clearing snow from the 33-panel battery-connect array on the community hall:

Battery storage capacity

Accessible panels

Money and emissions savings matter

The other 480 panels have different characteristics and therefore the same conclusions cannot be drawn without further study.

Guidance for Homeowners

Snowfall significantly hinders solar power production during Canadian winters. However, by keeping panels clear, significant energy, money and GHG savings could be gained. Figure 6 provides guidance to homeowners about factors to consider when determining whether clearing is justified for their specific situation.

This project could be extended or improved by:

Including analysis of all panels at Treehouse Village, since this study focused on one array

More precisely calculating the impact of partial cloud cover

Better understanding why some measurements were over 100% of the theoretical maximum

Further exploring the effects of temperature on power output

Investigating how different types of snow (e.g. wet, powdery) impact power output

Increasing baseline measurements on clear panels

Future research could explore ways beyond snow shovelling to remove snow from panels. For example, different panel installation angles or surface coatings could reduce snow accumulation.

Thanks to

Wayne Grozsko, solar expert, for helping with the calculation for the angle of sun and doing an interview

Scott Drennan, for providing me with the solar power data and doing an interview

Cate & Leon de Vreede, for their help and support

Susan Harvie, for lending me the paper cutter

Graham Mann, for helping with data and statistics

Becky Hogue, for helping with video editing

Brennan Caverhill, for inspiring me

Background Information

In Canada, there are currently more than 43,000 solar (PV) energy installations on residential, commercial and industrial rooftops, providing power directly to those homes and businesses.

Reference: Canadian Renewable Energy Association. (2026). Solar Energy. Retrieved from https://renewablesassociation.ca/solar-energy/

The effect of snow accumulation on solar panels has been well studied (metastudy).

Reference: Olusola Bamisile, Caroline Acen, Dongsheng Cai, Qi Huang, Iain Staffell. (2025). The environmental factors affecting solar photovoltaic output. Renewable and Sustainable Energy Reviews, (vol 208). ISSN 1364-0321. https://www.sciencedirect.com/science/article/pii/S1364032124007998

Due to absorption and reflection, snow inhibits photons from striking the surface of the panels.

Reference: Erlend Andenæs, Bjørn Petter Jelle, Kristin Ramlo, Tore Kolås, Josefine Selj, Sean Erik Foss. (2018). The influence of snow and ice coverage on the energy generation from photovoltaic solar cells. Solar Energy, (Volume 159, pages 318-328). ISSN 0038-092X. https://www.sciencedirect.com/science/article/pii/S0038092X17309581

A side-by-side comparison study of snow covered and cleared panels concluded that clearing panels reduces the overall power production by 5% over the year

Reference: Marni Sandell. (2012). The effect of snowfall on the power output of photovoltaic solar panels in Halifax, NS. Honours Thesis in Environmental Science, Dalhousie University, (April 2nd 2012). https://dalspace.library.dal.ca/items/0b202d23-270b-40d2-bc94-fa0154e91a91

How solar panels work

Reference: U.S. Department of Energy. (2026). How Does Solar Work? Retrieved from https://www.energy.gov/eere/solar/how-does-solar-work

Spray-on coating could make solar panels snow-resistant

Reference: A.Dhyani, C.Pike, J. L.Braid, E.Whitney, L.Burnham, A.Tuteja, Facilitating Large-Scale Snow Shedding from In-Field Solar Arrays using Icephobic Surfaces with Low-Interfacial Toughness. Adv. Mater. Technol.2022, 7, 2101032. https://doi.org/10.1002/admt.202101032

The solar panels used in this study were rated at 440W

Reference: product specifications sheet provided by Treehouse Village

Silicon panels lose about 0.3–0.5% efficiency per degree above 25°C, and gain some efficiency below it.

Reference: SolarTech. (2026). Solar Panel Operating Temperature: Complete Guide for Maximum Efficiency. Retrieved from https://solartechonline.com/blog/solar-panel-operating-temperature-guide/

The Nova Scotia Power rate paid by Treehouse Village for power in 2026 is $0.20

Reference: recent power bill (December 16 2025 to January 18 2026) provided by Treehouse Village

The Nova Scotia Power average GHG emissions intensity for 2025 is 0.528 kg of eCO2

Reference: Nova Scotia Power. (2026). Air Emissions Monitoring. Retrieved from https://www.nspower.ca/cleanandgreen/air-emissions-reporting

Images

[How do solar panels work?]. [Diagram]. Four Corners Clean Energy Alliance. https://fourcornerscleanenergyalliance.org/harnessing-the-suns-power-the-future-of-solar-energy/

(2007). [Picture of The Nakaya snow crystal morphology diagram]. [Diagram]. American Institute of Physics. DOI: 10.1063/1.2825081 https://physicstoday.aip.org/quick-study/snow-and-ice-crystals

(2018). [Pictures of panels with different angles with snow]. [Photograph]. Northern Alberta Institute of Technology. https://techlifetoday.nait.ca/articles/2018/solar-shines-in-dead-of-winter-even-in-edmonton

Burnham, L. (2022). Image of panels with snow-resistent coatings. Source: [U-M macromolecular science and engineering graduate researcher Abhishek Dhyani applies ice-and-snow-repellent coating to a solar panel in Fairbanks, Alaska.] [Photograph]. University of Michigan. https://news.engin.umich.edu/2022/01/spray-on-coating-could-make-solar-panels-snow-resistant/

Data Sources

Solar power production at treehouse Village: https://global.hoymiles.com/website/plant/detail/3347400

Outdoor temperature measurements at treehouse Village: CSV file emailed by Scott Drennan on February 16th 2026

Topic Experts

Wayne Grozsko, solar expert and instructor at Nova Scotia Community College

Scott Drennan, resident solar expert and technician at Treehouse Village

Graham Mann, statistician