Guide to Solar Panel Cleaning

May 16, 2025

Your solar panels work hard every day to convert sunlight into clean energy—but if they’re covered in grime, they can’t do their job as efficiently. Over time, things like dust, pollen, bird droppings, and leaves can build up on the surface of your panels and block sunlight. Even a thin layer of dirt can lower your system’s performance, meaning you’re getting less power and potentially higher energy bills.

Think of it like trying to see through a dirty window. The light still gets through, but not nearly as much as it should.

Keeping your solar panels clean doesn’t have to be a big lift. In this guide, we’ll walk you through everything you need to know—including how often to clean your panels, the safest ways to do it yourself, when it’s better to hire a pro, and what tools you’ll need. We’ll also share some simple safety tips, especially if you need to get up on the roof.

Let’s dive into how to keep your solar investment working its best!

Table of Contents

Why Cleaning Your Solar Panels Matters

Solar panels are all about soaking up the sun—but when they’re coated in dust, grime, or bird droppings, they can’t do that as efficiently. Even a light layer of dirt can block sunlight from reaching the solar cells, which means your system has to work harder and ends up producing less power. Over time, that adds up to lower energy output and potentially higher utility bills—basically the opposite of what you want from solar panels.

Plenty of everyday stuff can collect on your panels:

  • Pollen—a big one in the spring, especially if you live near lots of trees or plants
  • Bird droppings—yeah, it’s gross, but also stubborn and sticky
  • Dust and dirt—especially in dry or windy areas where rain doesn’t rinse things off
  • Leaves and sap—common if your roof is shaded by nearby trees
  • Air pollution and smog—if you live near a busy road or in a city, this can leave a thin film over time

Signs to Watch For

If you live in a dry climate where it rarely rains, you’ll probably need to clean your panels more often since there’s nothing to naturally wash off the grime. Spring can also be rough because of all the pollen flying around, and homes surrounded by trees tend to deal with a combo of leaves, shade, and sap. Any of these can impact your panels’ performance if left unchecked.

Keeping your panels clean helps make sure you’re getting the most energy (and value) out of your system. Think of it like washing your car’s windshield—things just work better when there’s nothing blocking the view. Up next, we’ll talk about how often to clean your panels and what to look out for.

How Often Should You Clean Solar Panels?

So, how often should you actually be up there giving your panels a good scrub? For most homeowners, a general rule of thumb is to clean your solar panels every 6 to 12 months. That’s usually enough to keep them in great shape and operating efficiently—unless you live somewhere with extra dust, pollen, or critters doing their thing.

But instead of marking your calendar every 6 months like clockwork, it’s more helpful to keep an eye on your system’s performance. Most solar systems have an app or online dashboard that shows how much energy you’re generating. If you notice a dip in your usual output—and it’s not due to weather or seasonal daylight changes—it could be a sign your panels need a little attention.

Seasonal changes can also play a big role. For example:

  • Spring is prime time for pollen buildup, especially if you’ve got a yard full of trees or blooming plants nearby.
  • Fall brings leaves, twigs, and sap—particularly if your panels are near overhanging branches.
  • Winter doesn’t usually require cleaning unless you live in a snowy climate, but even then, most snow melts and slides off on its own thanks to the panel’s smooth surface and tilted angle.

If your area rarely gets rain or you’re dealing with heavy dust, like in a desert or near ongoing construction, you might need to clean more frequently. On the flip side, if you live somewhere with regular rain and minimal debris, a good rinse from Mother Nature might be enough for a while.

Bottom line: check your panels every few months, keep an eye on your energy production, and give them a proper cleaning when they start looking a little dull or your numbers dip. It’s all about keeping things running smoothly with minimal hassle.

DIY Solar Panel Cleaning: Step-by-Step

Good news—cleaning your solar panels isn’t some complicated, high-tech task. In fact, with a few basic tools and a little bit of time, you can do it yourself and help keep your energy production on point.

Here’s what you’ll need:

  • A soft brush or sponge with an extension pole (no steel wool or anything rough!)
  • A garden hose with gentle water pressure
  • A squeegee to clear off excess water
  • A bucket of mild soap and warm water (think dish soap—not heavy-duty cleaners)

Aim for early morning or late evening for cleaning. During the midday sun, panels can get super hot, and spraying cold water on hot glass is a recipe for cracks—or just a streaky mess. Plus, you’ll avoid working in the heat and get better cleaning results when panels are cool.

Step-by-Step Cleaning Instructions:

  1. Shut off your system
    Check your solar panel manufacturer’s recommendations. Some systems suggest shutting off the inverter or disconnecting from the grid before cleaning, just to be safe.
  2. Rinse the panels with water
    Use your garden hose to gently rinse away loose dirt and dust. Avoid blasting it—gentle water pressure is key.
  3. Scrub lightly with soapy water
    Dip your soft brush or sponge into your soapy water and give the panels a gentle scrub. Work in sections and be careful not to put too much pressure on the glass.
  4. Rinse again
    Use the hose to rinse off all the soap and loosened grime.
  5. Squeegee dry (optional)
    If you want a streak-free finish, use a squeegee to remove leftover water—especially helpful if you live in a hard water area where spots are a problem.

What to avoid:

  • Harsh chemicals – Bleach, ammonia, or strong cleaners can damage your panels or leave behind residue.
  • Pressure washers – Too much pressure can crack the glass or mess with wiring. Stick to a regular hose.

Professional Solar Panel Cleaning Services

Sometimes, cleaning your own solar panels just isn’t in the cards—and that’s totally fine. If your roof is tricky to access, your panels are way up on a second story, or they’re covered in stubborn gunk that a garden hose just can’t handle, it might be time to call in the pros.

So, when should you hire a professional?

  • If your roof is steep, high, or unsafe to walk on
  • If your panels have heavy buildup—like caked-on dirt, bird droppings, or sap that won’t budge
  • If you have a large solar array and don’t have the time (or energy) to clean them all
  • Or honestly, if you just want the peace of mind that it’s done right!

What’s it going to cost?

On average, professional solar panel cleaning runs anywhere from $150 to $400, depending on how many panels you have, how dirty they are, and how tricky your roof is to access. Some companies charge per panel (like $10–$20 each), while others offer flat rates. If your system is part of a solar lease or maintenance package, the cleaning might even be included—so it’s worth checking.

What to look for in a solar panel cleaning service:

  • Licensed and insured – Always important when someone’s climbing around on your roof.
  • Experience with solar panels – Not all window washers or general cleaning services know how to handle delicate solar components.
  • Gentle, eco-friendly cleaning methods – Ask about the tools and solutions they use. Avoid anyone using high-pressure washers or harsh chemicals.
  • Positive reviews or references – A quick online search can tell you a lot about how professional and reliable they are.

Hiring a professional might cost a little more upfront, but it can be worth it for the convenience, safety, and results—especially if you’re not comfortable working on your roof. Plus, pros usually have the right equipment to clean efficiently and safely without damaging your panels.

Safety Tips for Roof Cleaning

Roof work comes with its share of risks, so if you’re tackling the job yourself, safety should be your top priority. Here are some simple tips to help you stay safe while getting the job done.

Start with ladder safety

Always use a sturdy ladder that’s tall enough to reach your roof without stretching or standing on the very top step. Make sure it’s set on level ground and locked in place. If possible, have someone hold the base of the ladder while you climb. And take your time—rushing up or down is how accidents happen.

Watch for slippery surfaces

Morning dew, leftover rain, or soapy water can make your roof slicker than you’d expect. If your panels are already damp or if you’re using water to clean them, be extra cautious. Wear non-slip shoes with good grip, and never step directly on the solar panels—they’re not designed to support your weight and can crack under pressure.

Use a hose extension or water-fed pole when you can

If your roof is too steep or you’re just not comfortable climbing up there, consider staying on the ground and using a hose with an extension or a water-fed pole with a soft brush. These tools let you reach your panels from a safer spot, especially if they’re mounted on a low-slope roof or carport. You may not get the deepest clean, but it’s often enough to rinse off pollen and dust between more thorough cleanings.

Preventive Measures to Minimize Dirt Buildup

Want to spend less time cleaning your solar panels? The best strategy is to keep them from getting too dirty in the first place. While you can’t avoid all the dust and pollen floating around, there are a few simple things you can do to cut down on grime and help your panels stay cleaner, longer.

Install critter guards or bird deterrents

Birds love rooftops—and unfortunately, they also love to hang out under solar panels. This leads to nests, feathers, and yes, plenty of droppings right where you don’t want them. Installing critter guards or bird deterrent mesh around the perimeter of your panels can keep pigeons and squirrels from turning your system into their new favorite hangout spot. It’s a small investment that can save you a lot of hassle.

Trim overhanging trees

Got branches hanging out over your roof? It might be time for a trim. Overhanging limbs drop leaves, sap, and other debris onto your panels—not to mention they provide extra shade, which can lower energy production. Keeping trees neatly trimmed not only helps reduce buildup but also improves sunlight exposure so your system works more efficiently.

Consider self-cleaning panel coatings

If you’re installing new panels or upgrading your system, ask your installer about self-cleaning or hydrophobic coatings. These special coatings help water and debris slide right off, kind of like rain-x for your solar panels. It doesn’t mean you’ll never have to clean them again, but it can definitely cut down on how often you do.

Common Myths About Solar Panel Cleaning

When it comes to solar panel maintenance, there’s a lot of well-meaning advice floating around—but not all of it’s accurate. Let’s bust a few of the most common myths that might be keeping you from giving your panels the care they actually need.

“Rain does all the cleaning.”

This one’s probably the most common myth—and while rain does help a little, it’s definitely not a substitute for a proper cleaning. Think of it like your car. Sure, it looks better after a downpour, but it’s not actually clean. Rainwater can leave behind streaks, spots, and a thin layer of grime. Plus, it won’t do much for stuck-on stuff like bird droppings or pollen buildup. If you want your panels working at full capacity, they still need a good scrub now and then.

“You need special equipment.”

You don’t need fancy tools or a solar tech certification to clean your panels. In most cases, a garden hose, a soft brush or sponge, and a little bit of mild soap will do the trick. As long as you’re being gentle and avoiding things like pressure washers or harsh chemicals, you’re good to go. If your panels are tricky to reach, a hose extension or water-fed pole can make the job easier—and safer.

“Cleaning voids your warranty.”

This one makes people nervous, but it’s not true—as long as you’re cleaning your panels properly. Most warranties stay intact as long as you avoid damaging the glass or electrical components. That means no abrasive scrubbers, no harsh cleaning agents, and definitely no standing or walking on the panels. In fact, some manufacturers recommend routine cleaning to maintain performance. If you’re unsure, just check your warranty terms or ask your installer what they suggest.

Conclusion

Keeping your solar panels clean might not be the most glamorous home task, but it’s one of the easiest ways to make sure your system keeps cranking out energy efficiently. A little dirt might not seem like a big deal, but over time it can chip away at your energy output—and that means lost savings.

Regular cleaning doesn’t have to be complicated or time-consuming. Whether you hose them off a couple times a year or bring in the pros for a deeper clean, staying on top of maintenance can help your panels last longer and perform better.

So keep an eye on your system’s output, check for visible dirt or buildup, and clean when it makes sense. And if you’re already in the habit of doing spring or fall home maintenance, go ahead and add solar panel care to that checklist.

FAQs 

Do solar panels need to be turned off to clean them?

It depends on your system. Some manufacturers recommend turning off the inverter or disconnecting the panels from the grid before cleaning—especially if you’ll be using water near wiring or connectors. Always check your user manual or ask your installer for guidance.

Can I walk on my solar panels to clean them?

Nope—don’t do it. Most panels aren’t designed to support body weight and walking on them can crack the glass, damage the cells, or void your warranty. Use a long-handled brush or hose extension, or hire a professional if you can’t safely reach them from the ground or a stable ladder.

Does cleaning solar panels really make a difference?

Yes! Studies have shown that dirty panels can lose 10–25% of their efficiency depending on how much grime has built up. Regular cleaning—especially in dusty, dry, or pollen-heavy areas—can help your system produce more energy and run more efficiently.

Additional Solar Resources