Should You Clear Snow Off Solar Panels?

The storm ends, the sun comes out, and you look up at the roof. The array is a flat white sheet, and the monitoring app, if you have one, says the system is producing nothing. Every instinct says to get that snow off. Before you reach for a ladder or a rake, it helps to know what the snow is actually doing, how long it usually stays, and what can go wrong when someone tries to move it.

This article is about snow on solar panels and the decision in front of you: clear it, wait it out, or call someone. If you want to know how much power panels make across a whole New England winter, we cover that separately in do solar panels work in the winter. Here we stay on the snow itself.

What Snow Does to Solar Production

Panels make electricity from light. Snow that covers the glass blocks the light, so a fully covered array produces little or nothing until the snow slides off or melts. SolarReviews says panels cannot generate power if they are covered in snow. Thick cover can stop production. Thinner cover may let some light through and leave a little output.

Snow cover usually costs you production for a while and then passes, but very heavy buildup or visible damage is worth a professional look. The Sandia National Laboratories page on snow and photovoltaic performance says published estimates of energy loss from snow range from 1 to 12 percent annually, with monthly losses as high as 100 percent, depending on location and weather conditions. Those are published research estimates, not a forecast for any one house. Sandia also notes that systems which shed snow quickly make more energy available.

Two things work in your favor. First, panels sit at an angle, and EnergySage notes that snow often slides off without any help. Second, SolarReviews notes that dark panels attract heat, which makes it easier to melt snow.

Cold itself is not the enemy. EnergySage points out that cold temperatures usually improve panel output, and that output starts to decline once panels get hot. The trouble in January is cover and short days, not the temperature.

Will Snow Damage the Panels?

Usually not. EnergySage says snow and ice accumulation will usually not be heavy enough to cause damage, and that panels carry weight ratings, with higher pressure ratings meaning better resistance to heavy snow. Panels and mounting systems have specific load limits, so if snow piles up unusually deep, ask your installer to take a look instead of assuming it cannot do harm.

We are not going to quote a snow load number for your roof. The rating of your specific panels and the way they are mounted are in your installation paperwork, and your installer can read them to you if a heavy snow worries you.

Should You Clear It or Leave It?

The safest answer is usually to leave it. Here is why.

• – The loss is temporary. Snow tends to move on its own once the sun and the tilt of the array go to work.
• – Clearing it yourself carries risk, which the next sections cover.

Leaving ordinary snow cover alone is usually reasonable. Very heavy buildup, dangerous ice or signs of damage are different, and call for a professional.

Why Sliding Snow Is a Hazard

Panel glass is smooth and the array sits at an angle, so when snow finally lets go, it often moves all at once. A sheet of snow and ice can drop off the roof edge with little warning, and it can be heavy.

That matters most below the eaves. Think about what sits under the array: a front walk, a driveway, a spot where a dog likes to lie, a child’s play area. SolarReviews describes snow guards as a way to keep snow from sliding off unexpectedly and landing on people or landscaping below.

A few habits cut the risk:

• – Keep people and pets away from the area under the panels after a heavy snowfall and while the sun is warming the roof.
• – Park cars out from under the roof edge when you can.
• – Do not shovel or stand directly below the array right after a thaw begins.

If snow sliding off the roof is a recurring problem at your house, mention it to your installer. Ask whether snow guards make sense for your roof and your layout. Whether they do depends on the roof, so it is a question for someone who can look at it.

What Not to Do

You will find plenty of advice online about getting snow off panels, and some of it is risky.

• – Do not climb on the roof or lean a ladder against it to reach the array. Snow and ice on a roof make for very poor footing, and a fall from a roof is a serious injury.
• – Do not use a roof rake from a ladder, and do not stretch a pole across the roof to scrape the panels.
• – Do not pour hot water on the panels. Water can refreeze into ice on the roof.
• – Do not scrape or chip at the panels with a shovel, a metal tool, or anything hard.
• – Do not touch the panels, the wiring, the inverter, or the batteries to “help” snow along.

SolarReviews notes that cold and icy conditions can be hazardous for installation work, which is part of why the safest answer for a homeowner is to stay on the ground and let the weather do the work.

Electrical and Damage Concerns

After a storm, if you see a panel that is cracked, shifted, hanging off the roof, or a cable that is exposed or dangling, do not touch it and do not go near it. Call a professional.

If you ever see smoke or flames, see or hear sparks, smell gas or something burning, or a carbon monoxide alarm sounds, get everyone out of the house and call 911 from outside first.

When It Is Worth Calling a Pro

Waiting is fine for most weeks of most winters. A call makes sense in a few situations:

• – Snow has covered the array for a long stretch and the production loss is bothering you, for example after several storms in a row.
• – Ice has built up along the bottom edge of the array or the roof edge above an entry, walkway, or driveway.
• – Snow stays on the array far longer than it stays on nearby roofs.
• – You notice something that looks wrong after a storm: a displaced panel, damaged wiring, or a monitoring app that shows a fault and not just zero production.
• – You are not sure whether what you are looking at is normal.

Winter roof work is a job for a professional. Rooftop Power offers solar panel snow removal, so if you want snow cleared, that page explains what the service covers and how to ask for it.

A professional visit is also a good time to ask the other questions that come up in winter: whether the system is performing the way it should, whether a monitoring alert needs attention, and whether anything needs service. Our maintenance and service page covers what we can look at on an existing system.

How to Tell If Snow Is the Reason Production Dropped

Zero production on a snowy day does not always mean snow is the cause. A few checks from the ground or from inside help you decide.

1. Look at the roof from the yard if you can see it clearly. If the array is visibly covered, snow may explain it, but check for monitoring faults and call your installer if anything else looks off. 2. Check whether the production reading is zero across the whole array or only for part of it. Part of an array can clear before the rest. 3. Check the weather. A heavy overcast day cuts output too. 4. If the roof is clear and the sun is out and production is still zero, call for service. That points to something other than snow.

Do not go up to look closer. A view from the ground, plus the monitoring app if you have one, is enough.

Where Rooftop Power Fits

Rooftop Power has worked on more than 4,000 solar and roofing projects, is BBB Accredited with an A+ rating, and uses in-house crews, not subcontractors. If snow is sitting on the panels, we offer solar panel snow removal so you do not have to go near the roof. If you are still deciding on solar and want to see how it fits a New England house, you can request a quote.