Published: 22 Nov, 2025 | By Solar
As soon as winter hits, users with an intent to switch to solar power are in a dilemma when choosing the right rooftop solar panel for homes and other applications. Their primary concern generally is around the ROI during the colder months. A pertinent concern often bugs them: Do solar panels work in winter? Are there performance issues when the temperatures dip?
For most, it would be astonishing to know that solar panels actually work better during colder months of the year. Let’s understand why this is so and what users can do to ensure a consistent and optimum energy production performance during winter.
Although perceived as an unlikely phenomenon by most solar power supporters, solar panel efficiency in winter actually improves due to various factors. In winter, every photovoltaic cell on a solar panel can produce higher units of electricity than in summer. This is because of the cooling effect on the cells that prevents overheating, boosting their generation performance.
Every panel is rolled out of the factory after being tested to function in 25°C. This is the optimum temperature that ensures maximum operational efficiency of a solar system. Every centigrade above 25° causes the panels to lose 0.3% to 0.5% of production efficiency. In summer, the efficiency of a panel can take a major hit when temperatures cross the 50°C mark.
The situation is opposite in winter, where panel efficiency improves beyond the rated performance metrics even when the mercury dips to 2°C or 5°C. Colder conditions allow the cells to churn out more voltage from the same or even lower amount of sunlight.
Take, for instance, the installations in most Himalayan states, i.e., Ladakh, Himachal Pradesh, Uttarakhand, Assam, Sikkim, Arunachal Pradesh, etc. The average per unit improvement in power production efficiency ranges between 12% to 18% in December and January. The wind chill causes the panels to get way colder than the testing conditions, enhancing the production ability of each cell.
Some of the best solar panel companies in India keep track of these seasonal temperature changes while testing the panels for locations such as the ones mentioned before.
It’s not the temperature that causes a decline in solar energy production in winter; it’s the availability of consistent sunlight and shorter day length. Be it an off-grid or an on-grid solar system, the limited availability of surface sunlight disrupts the ability of the photovoltaic cells to capture and produce electricity at peak efficiency.
First, the sun follows a lower arc across the sky. By the time it’s December and early January, the sunrays cease to drop as sharply as in summer. This is due to the dense atmosphere, which hinders the light, scattering or absorbing it before it reaches the panel surface.
Second, right after 21st June (summer solstice), days in India and most of the Northern Hemisphere start getting shorter as these regions start getting farther from the sun. This affects the day length, and by the time it is December and January, the sunlight duration decreases from an average of 14 hours for a city like Delhi in summer to 10 to 10.5 hours in winter.
This 30% decrease in daylight hours contributes significantly to the reduction in solar electricity production. Moreover, the estimate excludes early morning and evening light availability during winter days, another detrimental factor that further reduces the production capability of your panels.
Northern Indian states witness a 35%-45% drop in production when compared to the summer production levels. There is, however, a different side to this argument; installations in most of the states in India, except the Northern ones, receive plenty of sunlight and therefore witness only 15% to 20% reduction in power production capacity.
Gaining clarity on these metrics makes a difference in setting real ROI expectations and revenue prospects when calculating solar system prices for home price estimates. It’s a definite red flag if a company is offering the same production efficiency for every season and geographical location.
If you live in Lucknow, Kanpur, Chandigarh, or anywhere across the northern plains, you know winter fog. Dense fog episodes can reduce the performance of solar panels in winter far more than temperature or daylight duration ever could.
When visibility drops below 500 meters during those thick morning fog conditions, your system's output can plummet by 80% to 90%. A rooftop solar panel for home installation with a 10-kW capacity is able to generate only 400 to 600 watts during foggy days.
This is where having an off-grid solar system price estimate with battery backup becomes valuable. While it won't solve the fog problem, it does mean you're drawing from stored energy generated during clearer days rather than depending entirely on real-time production during foggy mornings.
Interestingly, when you compare the seasonal impact on solar panel efficiency, monsoon often hits harder than winter in many parts of India. July and August cloud cover across Maharashtra, Karnataka, and coastal regions can suppress generation by 60% to 70%.
The difference is timing and duration. Monsoon's severe impact concentrates into two to three months, while winter spreads its moderate reduction across four to five months. Over the course of a full year, both seasons balance out in terms of reduced production from optimal conditions. This is why the best solar panel company in India calculates annual returns rather than focusing on any single season's performance.
For most Indian installations, snow isn't a major concern. Only high-altitude regions and northernmost cities occasionally deal with significant snowfall. But when it does happen, understanding the dynamics helps.
Light snow under 2 centimetres typically melts within hours. Your panels generate heat when sunlight penetrates through thin snow layers, warming the surface to several degrees above ambient temperature. The dark backing sheet accelerates this melting process naturally.
Heavier accumulation above 10 centimetres blocks sunlight completely until it clears. The good news is that proper installation angles between 30 and 40 degrees help snow slide off naturally within a day or two. Panels mounted at steeper angles shed snow faster than those installed nearly flat.
Here's an unusual benefit: once panels clear, the white snow covering surrounding ground and rooftops reflects additional light onto your panels from below. This reflected light can boost production by 15% to 20% temporarily, partially compensating for lost generation during the snow cover period. Most importantly, never try to manually clear snow from your panels. The risk of damaging the glass surface or the mounting structure far outweighs any benefit from slightly faster clearing. Trust the system design and natural melting process.
Generic maintenance advice doesn't account for winter-specific challenges. Here are tips for solar panels in cold weather that actually matter for Indian conditions.
Winter may turn out to be a blessing in disguise for installations, based on different geographical and climatic conditions. An on-grid solar system is the ideal choice when you want to generate income from surplus power output that you can sell to the public grid through net metering. Reduced consumption during winter opens the window for your system to store excess power, which is added to your bill through net metering in the form of tariffs.
Many net metering policies value the electricity you export during winter similarly to summer, even though the grid's demand patterns differ. This temporal arbitrage means your winter kilowatt-hours sometimes provide better economic returns than summer production that gets consumed by your air conditioners.
When evaluating the solar system for home price proposals, insist on seeing monthly production estimates, not just annual figures. Any installer showing identical output across all twelve months either lacks experience or is overselling the system.
A properly sized system will under-produce relative to your consumption during January and February, requiring some grid imports. It will over-produce during April, May, and June, creating net metering credits. Over a full year, these balance out to deliver the promised returns. Understanding this seasonal rhythm prevents disappointment during your first winter with solar.
The key metric is annual production and annual savings, not any individual month's performance. December's lower output doesn't mean your system failed; it means it's performing exactly as designed within natural seasonal constraints.
Even with reduced winter generation, solar panels in winter continue providing value. They're generating clean electricity every single day, reducing your grid dependence and reducing your electricity bills. The technology doesn't hibernate or shut down; it adapts to available conditions and keeps working.
India's climate actually favours solar economics despite winter challenges. Our harsh summers with long days and intense sunlight produce enormous generation that more than compensates for winter's shortfall. Southern and western regions experience even less winter variation, making year-round production quite consistent.
The best solar panel company in India provides transparent projections accounting for seasonal variations specific to your location.
Do solar panels work in winter? Absolutely. Despite the fog, shorter days, and dew accumulation, panels still function during winter. Although the output capacity is not as much as it is in summer, the technology is not crippled by the harsh frost.
Through a comprehensive understanding of winter solar panel efficiency, users can get a realistic idea of what system size to choose, when to schedule regular maintenance, and the cost estimate for the installation, components, batteries, ROI, savings, and revenue after the break-even period.
For brands like Spectra Solar Power, every solar installation is a commitment to quality, performance, and cost-efficiency delivered with utmost consistency. Users can get their rooftop solar panels for home use installed with zero repair & replacement costs and a 25+year warranty.
Our experienced installers carry out an installation within 30 days and ensure a Plant Performance Guarantee (PPG) through which every plant installed generates 20% more electricity than panels from other brands. Government subsidies from the state and centre are also taken care of by us for your convenience.
