Do solar panels work in winter, snow and clouds?

Yes. Solar panels work in winter whenever light reaches them, and cold itself helps: the Department of Energy (DOE) says photovoltaic (PV) modules run more efficiently in cold.¹ Short days, a low sun and snow cut winter output. In a PVWatts model of an eight-kilowatt Silver Spring array, December comes out at about 53 percent of July.²

Do solar panels work in cold weather?

Yes. PV cells make electricity from sunlight, and the cold works in their favor.³ DOE says PV modules operate more efficiently in colder weather, because temperatures above 77°F cause voltage to drop.¹ Winter output falls for another reason: shorter days and a lower sun.

Higher efficiency still doesn’t mean higher output. Efficiency is how well a panel converts the light it gets. Output is what you collect over a whole day, and a winter day hands the panel much less light. DOE’s solar radiation page says that in the middle latitudes the sun’s rays are far more slanted during the shorter days of winter. Its example is Denver, near 40 degrees north, which gets nearly three times more solar energy in June than in December.⁴ The Silver Spring location modeled below sits at about 39 degrees north.⁵ A frosty, clear January morning is good for the panels, but it can’t give back the missing daylight hours.

PVWatts, the model used later in this guide, handles the cold bonus on its own. The National Laboratory of the Rockies (NLR) help page says the tool calculates temperature-related losses from cell temperature, so you shouldn’t add a temperature loss yourself.⁶

Do solar panels work on cloudy winter days?

They do, at lower output. Clouds, dust and air pollutants scatter sunlight, which DOE calls diffuse radiation. DOE also says atmospheric conditions can reduce direct-beam sunlight by 10 percent on clear, dry days and by 100 percent on thick, cloudy days.⁴ Thicker cloud means less light reaches the cells, so output falls with it.⁴

A thin, bright overcast and a dark storm deck are very different days, so a flat “cloudy-day discount” is a guess about the weather. The monthly figures below come from a typical-year weather file. They smooth over gray weeks instead of predicting them.⁵

How much less do panels make in a Maryland winter?

In a PVWatts run on October 17, 2026, an eight-kilowatt Silver Spring array makes 615.8 kilowatt-hours (kWh) in December and 1,166.5 kWh in July, about 53 percent as much.² December through February add up to roughly 18 percent of the modeled year’s 11,024 kWh.²

The three winter months total about 2,037 kWh, and June through August total about 3,347 kWh.² PVWatts comes from NLR, which was the National Renewable Energy Laboratory until December 2025.⁷ The table uses the model’s monthly alternating-current (AC) output. An array’s capacity is a direct-current (DC) rating, so it isn’t the energy you get each month.⁵

The weather file is the NLR National Solar Radiation Database (NSRDB) typical meteorological year, labeled tmy-2020. It represents a typical year, not a forecast for the coming winter.⁵

A hypothetical reading. Say a household used the same amount of electricity every month, and an array covered all of it in July. Because the modeled December output is about 53 percent of July, that same array would cover only about half of December’s use before any additional snow losses are counted.² The grid, and any net-metering credits you’ve banked, fill that gap.

Your roof will differ from the example in three ways. Direction and tilt change the inputs. Shade at your property may be heavier or lighter than the assumed losses. And real winter weather, snow included, won’t match the weather file.^5,6 A site-specific estimate starts with a residential solar assessment. Our guide on how many panels a house needs shows how a household’s usage drives sizing.

Do solar panels work when it snows?

Yes, with pauses. DOE says ice and snow can limit production, but most snow melts quickly off PV systems or blows off.¹ A DOE weatherization-program FAQ gives melt times of several hours to several days and says snow typically doesn’t cost a significant amount of production, partly because winter output is already low.⁸

That FAQ was written in August 2022 for weatherization-program households, so treat it as general guidance. How much a particular snowfall costs depends on your equipment and roof.

Four things set how long snow stays: how much fell, the air temperature, how sunny it is, and the pitch of the roof and the system.⁸ Tilt matters. DOE says steeper tilt sheds snow faster, with significant gains around 30 to 35 degrees, which it notes is steeper than a typical roof.¹ The 20-degree tilt in the model above is shallower than that, so the table isn’t a snow-clearing forecast.

Snow is a structural issue as well as a production one. Because panels sit at a tilt, DOE says snow slides down and piles up unevenly along the lower frame, which puts more stress on the bottom of the module. Ice adds weight and can shift it unevenly across the modules and the structure underneath.¹

Those figures come from DOE’s winter-weather guidance, which is written for system designers.¹ Only a qualified professional can judge your roof and your equipment.

Should I clear snow off my solar panels?

Rooftop snow removal is hazardous work. The Occupational Safety and Health Administration (OSHA) says falls cause the most worker deaths and injuries during rooftop ice and snow removal, from roof edges, skylights and ladders, and it lists roof collapse, falling ice and power-line shocks among the other hazards.⁹

OSHA wrote that guidance for employers and workers, but the hazards are the same on any snowy roof. For damage, snow that won’t shed or a heavy buildup, call a qualified solar professional. Your manufacturer’s instructions and your installer can say whether any clearing method suits your equipment. The DOE FAQ mentions carefully removing snow with a long-handled snow rake after a heavy snowfall on a low-pitch roof in cold, cloudy weather.⁸

If production stays low after the snow is gone, something else may be wrong. Our guide to a solar system that isn’t producing lists what to check, and what to do when monitoring goes offline covers the app side. Soleil’s monitoring and maintenance service covers performance monitoring and fault diagnosis, including on systems other companies installed.

How do you read a winter production estimate?

A good estimate shows its assumptions, so you can see what drives the winter number. Check the weather file, tilt, shading and snow loss. PVWatts, for example, splits its default 14 percent system loss into named categories, and snow is one of them.⁶

Default (percent)

• Soiling2
• Shading3
• Snow0
• Mismatch2
• Wiring2
• Connections0.5
• Light-induced degradation1.5
• Nameplate rating1
• Age0
• Availability3

View the data as a table

PVWatts loss category	Default (percent)
Soiling	2
Shading	3
Snow	0
Mismatch	2
Wiring	2
Connections	0.5
Light-induced degradation	1.5
Nameplate rating	1
Age	0
Availability	3

Look at the snow line. A zero means the estimate assumes snow never sits on the array, or that someone clears it.⁶ That’s a fair simplification for a typical-year model, but keep it in mind when you compare a winter figure against your own January bills.

Four details tell you how far to trust any estimate:

1. Weather file. Is it a typical-year file, and does it assume any snow loss?
2. Tilt and direction. Do they match your actual roof?
3. Shading. How much does it assume, and where does that number come from?
4. Units. Is the monthly figure AC energy delivered, or just the array’s DC rating?

Do net-metering credits cover the winter?

Sometimes, if your account has a balance. Under Maryland’s net-metering statute, the utility carries unused net excess generation forward until your grid use eliminates it, your accrual period expires, or the account closes.¹⁰ A summer credit can offset a January bill.

That credit is a billing entry, not stored electricity, and you still rely on the grid whenever you import power.¹⁰

The rules differ by election. As of October 25, 2026, the statute reads like this:

An example, not a customer. Say a household on the 12-month election ends September with a surplus balance. That balance can offset imports in December and January. Whatever is left at the end of the April cycle gets paid out rather than carried into the next summer.¹⁰ The same surplus under an indefinite election would keep rolling forward.

These are bill credits, not tax credits. Our guides on the Maryland net-metering deadline and the successor program go deeper on the dates, and is solar worth it in Maryland puts seasonal output next to the bill.

How should you plan for a Maryland winter?

Think in seasons. In the modeled example, December came out near half of July. Treat snow as a short interruption unless a professional tells you something is damaged, and look at your utility account’s credit balance before you judge a winter bill.

To see how this plays out on your own roof and electric bill, book a free consultation or call (301) 953-4140.

Solar savings and incentive eligibility depend on your roof, your usage, your utility, and your tax situation. Incentive programs change and some have limited funding. We are not tax advisors — we will review your bill with you and tell you what you may qualify for. Confirm any tax credit with a qualified tax professional.

Sources (11)

1. U.S. Department of Energy, Solar Photovoltaic Hardening for Resilience: Winter Weather, published May 4, 2023, last modified May 11, 2026, https://www.energy.gov/cmei/femp/solar-photovoltaic-hardening-resilience-winter-weather; read October 25, 2026. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

2. Illustrative calculation, run October 2026, with the inputs sourced at ⁵. Monthly AC outputs come from the PVWatts run on October 17, 2026. The December-to-July comparison (about 53 percent), the December-through-February total (about 2,037 kWh, roughly 18 percent of the 11,024 kWh annual figure) and the June-through-August total (about 3,347 kWh) are arithmetic on those outputs. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

3. U.S. Department of Energy, How Does Solar Work?, published September 9, 2020, last modified October 21, 2026, https://www.energy.gov/cmei/systems/how-does-solar-work; read October 25, 2026. ↩

4. U.S. Department of Energy, Solar Radiation Basics, published October 27, 2020, last modified July 21, 2026, https://www.energy.gov/cmei/systems/solar-radiation-basics; read October 25, 2026. ↩ ↩² ↩³

5. National Laboratory of the Rockies, PVWatts model run on October 17, 2026, https://pvwatts.nlr.gov/, and PVWatts v8 API documentation (current page, read October 25, 2026), https://developer.nlr.gov/docs/solar/pvwatts/v8/ (inputs are illustrative assumptions). The weather file is NSRDB PSM V3 GOES tmy-2020 3.2.0. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

6. National Laboratory of the Rockies, PVWatts System Losses help page, https://pvwatts.nlr.gov/docs/help_system_sysloss.php (current page, undated; read October 25, 2026), which lists the default loss categories, the 14 percent default total and the zero snow default, and says temperature losses are calculated from cell temperature; and the PVWatts calculator page, https://pvwatts.nlr.gov/pvwatts.php (System Losses Categories, current page, undated; read October 25, 2026), which says the snow default is zero, “assuming either that there is never snow on the array, or that the array is kept clear of snow.” ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵

7. National Laboratory of the Rockies, NLR Style Guide (current page, undated), https://www.nlr.gov/comm-standards/editorial/full-text; read October 25, 2026. ↩

8. U.S. Department of Energy, Solar Frequently Asked Questions (Weatherization Assistance Program), PDF titled “August 2022” (hosted in the department’s February 2024 uploads), https://www.energy.gov/sites/default/files/2024-02/wap-solar-faqs_022624.pdf; read October 25, 2026. ↩ ↩² ↩³

9. Occupational Safety and Health Administration, Snow Removal: Know the Hazards, OSHA 3966-01, 2019, https://www.osha.gov/sites/default/files/publications/OSHA3966.pdf; read October 25, 2026. ↩

10. Maryland General Assembly, Public Utilities Article section 7-306(f)(5) and (f)(6), current statute text (undated), https://mgaleg.maryland.gov/mgawebsite/Laws/StatuteText?article=gpu&section=7-306&enactments=false; read October 25, 2026. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

11. Maryland General Assembly, 2026 Laws of Maryland, Chapter 353 (House Bill 1532), the Utility RELIEF Act, amending section 7-306(d) and adding successor-program provisions in new section 7-306.4, enrolled text, https://mgaleg.maryland.gov/2026RS/chapters_noln/Ch_353_hb1532E.pdf; read October 25, 2026. ↩ ↩²