How to Clean Solar Panels and Increase Efficiency

cleaning solar panels

Transitioning to solar energy brings with it many advantages and facets, but two of them stand out most: You’re investing in a lower energy bill at the end of each month. And, you’re investing in the betterment of the environment by reducing your carbon footprint and minimizing your usage of fossil fuels.

But unlike dividend stocks or rental properties, a solar panel isn’t a passive investment, at least if you intend to maximize its value. Instead, you should remain proactive as a solar panel owner to ensure it remains at peak performance, giving you all the benefits it should.

Failing to maintain and monitor your solar panel’s performance leads to problems with efficiency and limited savings. Beyond that, your panel won’t last nearly as long as it should. These pitfalls almost defeat the purpose of shifting to solar energy in the first place. Part of ensuring long-term peak performance is cleaning your solar panel properly–the topic of this very article.

Why Is It Important To Keep Solar Panels Clean?

Solar panels operate via light entering the solar cells. Without keeping solar panels clean, dirt will accumulate over time, preventing light from entering. This type of buildup also results from bird droppings, pollen, or dust. All these debris types prevent light from reaching solar cells. Over time, less energy gets produced, and your panel fails to serve its purpose. In fact, dusty solar panels experience something in the neighborhood of 35% drop-off in energy production, according to studies.

Normal Grime Hardly Affects Solar Panels

On many standard solar panels, everyday grime isn’t that much of a factor. A lot of the time, the rain washes such debris away, keeping your panel relatively clean. One study shows that cleaning your panel only amounts to a 1% increase in output. Though, the above notion isn’t anything close to a hard-fast rule. Many areas don’t get much rain, and you could also live where dust, dirt, and more substantial debris are more abundant.

Note that you’ll experience a 2% yearly output improvement in rainier areas by cleaning your panel twice per year. That’s relatively insignificant, but these installations last a long time, so minor short-term changes might prove valuable in the long run. You’ll also need to weigh in the factors below to determine how much cleaning your panel requires:

Flat Solar Panels Need Regular Cleaning

Rain only washes the grime from angled panels. When a panel is flat, there’s nowhere for the water to travel, so it creates little pools and puddles after rainfalls. It will then evaporate and leave behind grime. Also, more substantial debris such as leaves might land on your panel, lingering over the long haul and draining output. While a thin layer of grime allows enough light to pass through, leaves block light greatly reducing your panels’ energy output. For these reasons it is recommended that any solar panel installed on a flat roof should be tilted at least 10-degrees. In the case that installing your panels with a tilt is not possible, you’ll need to clean them to maintain peak performance. To that point, research shows that cleaning flat panels will double their output over time.

Frameless Solar Panels Stay Cleaner At Low Angles

Many scenarios exist where homeowners can’t install their solar panels at 10 degrees. In which case, frameless panels are a potential answer. Around their edges, frameless panels don’t have metal frames. These are often called double-glass panels or glass-on-glass panels since the solar cells are sandwiched in the glass. Since there’s no frame, water and debris falls off more easily, and the panel remains clear, at least compared to panels with a frame.

How Often Should You Have Your Solar Panels Cleaned?

This question causes plenty of debate between solar panel specialists. Still, there does appear to be at least one general consensus on the matter. Namely, it’s agreed you should get your solar panels cleaned – at least – every 6 months.

As was discussed in a previous section, there are other factors (e.g., location and geography) where you might need your panels cleaned more or less frequently.

How Location Affects Solar Panel Cleaning

Living in arid, desert climates means you’ll need to get your solar panels cleaned more frequently. Without the rain, all the dust and debris will continue to build up, hampering performance. Living in wooded areas where bird droppings and leaf debris is unavoidable also means your panels will require more frequent cleaning.

On the other hand, in areas with plenty of precipitation and strong winds, your solar panels won’t require much cleaning as nature will take care of the majority of the work for you.

How To Gauge When It’s Time To Clean Solar Panels

You’ll have an obvious sign you need to clean your solar panel when it starts to decline in output and efficiency. There’s more pollution during winter compared to summer because pollutants closer to the ground get trapped in the cold air. So, your best bet is to clean your solar panel during the spring–especially since they’re too hot during the summer for touching. (Pro tip: clean panels during the morning or early evening when it’s cooler)

Types Of Solar Panel Debris

Debris isn’t all one and the same. It comes in different forms and presents various types of challenges for your solar panels:

Dust & Grime

Dust and grime don’t impact your panel’s performance too much and are easily washed away by the rain. Depending on where you live, you might need to watch for dust and grime buildup, primarily if you reside in a drier area. That said, these pieces of debris are the least of your concern when it comes to cleaning your solar panel.


More substantial than dust and grime, leaves are proven to adversely impact your solar panel’s performance. Keep an eye out for leaves blocking the light from reaching the cells.

Snow & Ice

Thankfully snow and ice are easily melted by the heat solar panels generate and they’ll typically be gone before causing any damage to your panel. Unless you have your panels installed completely flat, snow and ice shouldn’t be of much concern in terms of solar panel damage. That said, even if snow builds up on your panels it’s best not to physically brush snow off your solar panels as it may be hard to see what you’re doing and any damage you cause would likely void your warranty.

How To Clean Your Own Panels

When your solar panel isn’t caked down with any sticky debris, and it’s mostly just dirt and grime, cleaning doesn’t take much effort. Merely spraying your panel from the ground with a garden hose should do the trick.

If your roof is low enough to spray from the ground but tall enough that a pressure washer is required, don’t directly blast your panel. This would be too harsh, creating scratches, casting tiny shadows on the cells beneath the tempered glass layer. In turn, you’ll cut into your panel’s efficiency, defeating the purpose of cleaning in the first place.

Of course, sometimes heavier dirt buildup might accumulate on your panels. For these situations, you’ll need the following materials:

  • Squeegee and a soft brush (long enough to reach where you’re working)
  • A long enough water hose to get to your panel
  • Water combined with some mild soap in a bucket

Now, here’s what the process of cleaning should look like:

  • With clean water from the hose, rinse your solar panels to loosen dirt.
  • Gently wash the surface of the panels with your soft scrubber after dipping it into your soapy water bucket.
  • Rinse panels again with your hose.
  • Use squeegees until the panel is dry.
  • Keep repeating this process and change your position when required until the panels are cleaned.

Cleaning Panels Yourself May Not Make Economic Sense

For roof-mounted solar panels, you’ll require a ladder to reach it, which you might not own. Furthermore, you might have to purchase the other tools needed for cleaning.

Now, DIYing makes sense when you use all those appliances listed in the previous section for other tasks around the house. But for the most part, you’ll only be cleaning your solar panel once per year (maybe twice). So, if you only need those tools to clean your solar panels, buying them doesn’t really make much sense.

There are also physical risks involved when your solar panel is on the roof. And since you aren’t a professional, it’s likelier you make mistakes and potentially hurt yourself. While that may not be an immediate economic risk, medical bills can pile up pretty fast.

How Much Does It Cost To Clean Solar Panels?

Nationally, there’s a $150 to $330 average to get your solar panels professionally cleaned. And the per-panel average rate comes in at around $15 to $35.

Averages being what they are, the above numbers will fluctuate depending on these factors:

  • How much work is needed
  • Panel size
  • Location
  • Slant and height of your roof

Why It’s Best To Leave Solar Panel Cleaning To Professionals

One of the first reasons you’ll want to leave solar panel cleaning to the professionals is your safety. In most cases, roofs are high off the ground, slanted, and slippery–and not worth the injury risk of DIYing. The professionals have the safety equipment and skills to prevent accidents and get the work done 100% right, the first time. There’s also the fact that professionals know the ins and outs of cleaning your solar panels and have done it many times before. These skilled individuals will find any potential discrepancy impacting performance that you might miss. This could play a massive role in enhancing your panel’s output and lifespan.

On average, it shouldn’t cost more than $330 to get a full solar panel system cleaned, so it’s not too expensive for peace of mind alone. Provided your solar panel is easy to reach and low maintenance to clean, then, by all means, go ahead. However, if the process of cleaning presents various challenges, go with the pros. They’ll do it safely, successfully, and affordably. If you’re interested in learning more about solar panel cleaning, solar panel maintenance, solar panel pricing, or would just like to speak to someone about a solar panel installation quote, contact us today!