Yes, solar panels work in winter and snow. Despite common misconceptions, solar panels actually perform more efficiently in cold weather and experience minimal production losses from snow coverage. Research shows that snow-covered panels lose only about 3% of their annual energy production compared to cleared panels, making solar a viable investment even in the snowiest climates.
This comprehensive guide covers everything you need to know about winter solar performance, including real-world data, safety considerations, and strategies to maximize your system’s effectiveness year-round.
How Solar Panels Actually Work in Winter Weather
The Science: Solar Panels Convert Light, Not Heat
Solar panels generate electricity through the photovoltaic effect, which occurs when sunlight hits solar cells and creates an electric current. This process depends on light, not temperature, meaning panels continue producing power as long as sunlight reaches them, regardless of how cold it gets outside.
Why Cold Weather Improves Solar Panel Efficiency
Contrary to popular belief, cold temperatures actually boost solar panel performance. Solar panels are more efficient in colder weather than hot, with cold temperatures typically improving solar panel output because:
- Electrons move more freely in cooler temperatures
- Less resistance occurs in the electrical circuits
- Panels avoid efficiency losses from overheating
Temperature Coefficient Explained with Real Examples
Every solar panel has a temperature coefficient that measures how efficiency changes with temperature. Most panels are rated at 77°F (25°C), and their output power starts to degrade when the panel’s temperature rises above this point.
Typical temperature coefficient ranges:
- Crystalline solar cells typically have temperature coefficients of about -0.5% per degree Celsius
- Advanced technologies like HJT have lower coefficients of -0.2% to -0.3% per degree Celsius
- Most solar panels have temperature coefficients ranging from -0.3% to -0.5% per degree Celsius
In winter temperatures of 32°F, panels with typical temperature coefficients would operate at 10-13% higher efficiency than their rated capacity.
Snow Coverage Impact: Real-World Performance Data
NAIT 5-Year Edmonton Study Results
The Northern Alberta Institute of Technology (NAIT) conducted a comprehensive 5-year study on snow’s impact on solar panels in cold climates. The study found that snowfall on photovoltaic solar panels results in about a 3% energy loss, which was significantly less than the 20% drain that industry had traditionally estimated.
Key findings from the study:
- 3% total annual energy loss from snow coverage
- The angle of the solar panels has a far greater impact on energy production than snowfall, with the ideal angle for maximum energy production with snow accumulation being 45 degrees
- Accumulating dirt and dust on panels can affect production loss more than snow
How Snow Affects Different Panel Angles
The NAIT study tested panels at various angles including 14°, 18°, 27°, 45°, 53° (site latitude) and 90°. Key findings:
- Lower angles (14°): Higher snow accumulation, greater production loss
- 45° angle: Optimal balance for snow shedding and energy production
- Steeper angles (90°): Minimal snow accumulation, best snow shedding
Most residential installations use 30-45° angles, which provide excellent snow shedding while maximizing annual energy production.
Regional Performance Data from Cold-Weather States
According to recent data from the Solar Energy Industries Association (SEIA), several northern states with harsh winters rank highly for solar installations, including Illinois, Ohio, New York, Indiana, Wisconsin, and Maine.
These states wouldn’t lead in solar adoption if winter weather significantly impacted system performance.
Why Snow Doesn’t Kill Solar Performance
Natural Snow Shedding from Angled Panels
Solar panels are typically installed at angles, and snow typically melts or slides off of panels due to this angled installation. The smooth glass surface provides minimal friction, allowing even light winds to help clear accumulated snow.
Panel Heating Accelerates Snow Melt
Snow is likely to melt off of panels faster than most other surfaces. Once part of the panel is exposed to sun, the panel begins operating, which raises the temperature of the panel surface, leading to faster melting.
Light Penetration Through Thin Snow Layers
Light is able to penetrate through 5 to 8-centimetre layers (2 to 3 inches) of snow, enabling panels to continue generating electricity even when covered. The combination of light penetration and panel heating quickly clears thin snow accumulations.
Albedo Effect: Snow Reflection Boosts Performance
In some cases, colder temperatures like snowy ones can positively affect the output of a solar panel system via the albedo effect. This is because the snow, when at the right angle and when it is not obscuring the panel itself, reflects sunlight up to solar cells from the ground, allowing panels a bit more sunlight. On cold, clear days, snow from the ground can reflect extra sunlight onto your solar panels like a mirror, enabling panels to produce even more electricity in cold weather.
Net Metering Balances Seasonal Variations
Most solar installations use net metering, which credits excess summer production against winter consumption. Since 70-80% of annual solar production occurs during March-October, summer surplus easily compensates for any winter reductions.
Winter Solar Panel Maintenance & Safety
Why You Should NOT Climb on Your Roof to Clear Snow
Safety Warning: Never attempt to clear snow from roof-mounted solar panels yourself. Snow should only be cleared if it’s safe to do so, such as on a flat commercial roof. For pitched roofs, experts recommend against clearing snow, as it’s just not worth it for the minimal gain in power efficiency.
- Icy roof conditions create extreme fall hazards
- Panel damage voids warranties
- Minimal production gains don’t justify the risks
- Insurance may not cover injuries from DIY maintenance
Safe Ground-Level Snow Removal Techniques
For ground-mounted systems or easily accessible panels:
- Use a soft-bristled brush on an extension pole
- Clear snow from the base to allow natural shedding
- Work from the ground level only
- Never use metal tools or sharp implements
Tools That Won’t Damage Panels
If you must clear accessible panels:
- Recommended: Soft foam brushes, rubber squeegees
- Acceptable: Leaf blowers for light, powdery snow
- Never use: Metal rakes, shovels, or ice scrapers
When Professional Cleaning Makes Sense
Consider professional solar panel cleaning services only if:
- Heavy snow persists for more than a week
- Ice dams form around panel edges
- You have a ground-mounted system requiring specialized equipment
For detailed maintenance guidance, refer to our comprehensive guide to solar panel cleaning for year-round care tips.
Maximizing Winter Solar Performance
Optimal Panel Angle for Snow Shedding
The ideal panel angle balances year-round production with snow shedding:
- 30-35°: Best for southern regions with occasional snow
- 40-45°: Optimal for northern climates with regular snowfall
- 45°+: Consider for areas with heavy, wet snow
Snow Guards: When and Why to Use Them
Snow guards prevent large snow sheets from sliding off panels suddenly. Install snow guards if:
- Panels are mounted above walkways or entrances
- Your area receives heavy, wet snow
- Local building codes require them
Battery Storage for Winter Backup Power
Solar battery storage provides crucial backup power during winter storms when grid outages are common. Benefits include:
- Power during extended cloudy periods
- Backup electricity during winter storms
- Ability to store midday winter production for evening use
Cold Climate Solar Success Stories
Northern States Leading Solar Adoption
Northern states are some of the states with highest solar usage, with states experiencing rough winter weather among the top states for installed solar capacity.
Antarctic and Alaska Solar Installations
Solar panels work in the world’s most extreme climates:
- McMurdo Station, Antarctica: Solar arrays are used in U.S. facilities like McMurdo Station in Antarctica
- Alaska installations: Solar panels are even used in Alaska despite harsh winters
- Arctic conditions: Residential solar panels are manufactured to function to at least -40 degrees
Winter Solar Installation Considerations
Can Panels Be Installed in Winter?
Yes, solar panels can be installed year-round in most climates. Installation considerations:
- Most installation time involves planning and permitting, not rooftop work
- Physical installation takes 1-3 days in suitable weather
- Installers work in temperatures above 20°F with proper safety measures
Winter Installation Advantages
Installing solar in winter offers several benefits:
- Lower prices: 10-15% discounts during off-peak season
- Faster scheduling: Less competition for installation dates
- Ready for summer: System operational for peak production season
- Immediate savings: Start offsetting winter heating costs
If you’re considering winter installation, explore our residential solar panel installation services to learn more about the process and benefits.
Financial Impact of Winter Performance
Annual Production vs Daily Variations
While daily winter production may drop 25% to 50% compared to summer peaks due to fewer sunlight hours, annual production remains highly predictable:
- Summer months (April-September) generate 70-80% of annual production
- Winter months (October-March) contribute 20-30% of annual production
- Net metering allows summer surplus to offset winter deficits
ROI Calculations Including Winter Performance
Solar ROI calculations already account for seasonal variations:
- Typical payback period: 6-8 years in snowy states
- 25-year savings: $20,000-$40,000 even with winter reductions
- System lifespan: 25-30 years with minimal performance degradation
Expert Tips for Winter Solar Success
Professional Installer Recommendations
Leading solar installers in cold climates recommend:
- Install panels at 40-45° angles for optimal snow shedding
- Use micro-inverters to minimize impact of partial shading
- Consider panel placement to avoid persistent shade from snow buildup
- Ensure proper system grounding for safety in wet conditions
Monitoring System Alerts
Modern solar monitoring systems help track winter performance:
- Set alerts for production drops exceeding 80% for more than 3 days
- Monitor individual panel performance to identify snow coverage
- Compare actual production to weather-adjusted estimates
Long-Term Performance Expectations
Over a 25-year system lifespan, expect:
- Year 1-10: 95-100% of rated production annually
- Year 11-20: 90-95% of rated production annually
- Year 21-25: 85-90% of rated production annually
Frequently Asked Questions
Do I need to shovel snow off my panels?
No, you should not shovel snow off your panels. Snow usually melts quickly and slides off the solar panels, requiring zero maintenance from homeowners. The minimal production gains don’t justify the safety risks.
Will heavy snow damage my panels?
Solar panels are designed to withstand heavy snow loads. You’d need a lot of snow for panels to be in danger of being damaged due to the weight of the snow. However, if you’re concerned about extreme snow accumulation, consult your installer about snow load calculations for your specific installation.
How much does winter reduce solar production?
Solar panels lose between 25% to 50% efficiency during the peak winter months (December and January) compared to summer peaks, but annual production only decreases modestly due to net metering balancing seasonal variations.
Should I wait until spring to install solar?
No, winter installation offers advantages including lower prices and faster scheduling. Installing in winter ensures your system is operational for the high-production summer months, maximizing first-year savings.
Do solar panels work during blizzards?
Solar panels produce minimal electricity during active blizzards due to heavy cloud cover and snow accumulation. However, they resume normal operation quickly once conditions clear, often within hours of storm passage.
Bottom Line: Solar panels work effectively in winter and snow conditions, with minimal impact on annual energy production. The combination of improved cold-weather efficiency, natural snow shedding, and net metering makes solar a smart investment even in the snowiest climates. Focus on proper installation angle and safety rather than worrying about winter performance—your solar investment will pay off year-round.