How to clean solar panels: Your guide to solar panel cleaning

How to clean solar panels: Your guide to solar panel cleaning

Published 9/25/2023

Hello, solar panel owners and enthusiasts! Eager to dive into solar panel maintenance? You're in the right spot.

Solar panels are a fantastic investment in renewable energy, but they’re not completely maintenance-free. Dust, bird droppings, and even snow can diminish their efficiency, so it's a good idea to ensure that panels are kept clean regularly.

Whether you're a homeowner with an existing solar panel system or you’re contemplating going solar, consider this guide as your source for keeping panels clean and running efficiently. We’ll break down the what, when, and how of solar panel cleaning, so you can be sure to maximize your investment. 

What's inside:

  • Why clean solar panels?: Discover why a clean panel array ensures maximum panel output.

  • When to clean: Recognize signs indicating your panels require a thorough scrub and the frequency for doing so.

  • How to clean: From soap-less brushes to advanced nanoparticle coatings, we'll discuss every method available.

  • Safety first: Tips for ensuring safe, effective cleaning.

  • FAQs: Answers to all your pressing questions about solar panel cleaning.

When to clean solar panels?

Cleaning solar panels can actually be pretty subjective. Depending on things like your area, local weather conditions, or solar design, you may never have to clean your solar panels. It actually takes a lot of buildup of dirt or ash to negatively impact solar production, and typically, most areas around the country receive enough rainfall throughout the year to keep the panels clean.

That being said, if you live in a really dry climate with lots of dirt in the air, if you’ve recently experienced some intense weather, or if you’re just a little more concerned about cleanliness than the average person, we suggest you go ahead and clean your panels. When cleaning your panels, please consider the following:

Your personal safety. Please do not get on the roof to clean your panels. Getting up on the roof can be dangerous without the proper safety precautions. 

Local weather conditions. Does it seem overcast to you? Did your local meteorologist predict a high chance of showers tomorrow? If yes, then we say wait. Why do the work of cleaning your panels when Mother Nature could do it for you?

The time of day or year. Is it crazy hot outside? If yes, then putting cold water on your panels may actually damage them. Better wait until it cools down. Is it slick or wet outside? Maybe wait until it’s safer to maneuver equipment.

In the end, the best thing to do is to use your intuition. If you think the runoff from rain or snow will take care of the cleaning naturally, or if it’s mild enough that you can easily use a long hose to clean the panels from the safety of the ground, then go ahead and clean those panels.

Quick take: Lowered energy efficiency and apparent dirt indicate it's time to clean.

How often to clean solar panels?

So, what's the ideal frequency? As we mentioned, things like your location and environmental conditions are significant factors when it comes to how often to clean your solar panels. If your solar system has performance monitoring (more on that later) and you do not notice a decrease in efficiency, you do not need to clean the panels. For those that do find their panels require cleaning in order to maintain performance, the average cleaning frequency is bi-annually.

Quick take: Cleaning intervals vary, but cleaning twice a year works for most people when conditions otherwise decrease efficiency.

Methods for cleaning solar panels

Cleaning solar panels isn't a one-size-fits-all task. Different methods suit different needs, each with its own set of pros and cons.

Manual cleaning

The soft brush and mild, eco-friendly soap method.

Note: If you use this method, be sure to use a long-handled roof brush so you can clean your panels from the safety of the ground. 

  • Pros: Straightforward

  • Cons: Labor-intensive, risk of soap residue if not rinsed well.

Tools for cleaning solar panels:

  • Soft-bristle brush. Choose a long-handled brush that’s specially-designed for solar panel cleaning. 

  • Hose with spray nozzle

  • Bucket

  • Mild detergent or soap-free cleaner

Step-by-step guide:

  1. Turn off the solar panel system for safety.

  2. Fill a bucket with water and mild detergent.

  3. Gently scrub the panel surface using a long-handle soft-bristle brush while standing on the ground.

  4. Rinse using a hose, opting for a gentle flow via the spray nozzle.

Soap-free brushes and sponges

Excellent for removing dirt and grime without residue. Make sure to use specialized solar panel cleaning brushes or sponges.

  • Pros: Designed for cleaning without soap residues, eco-friendly.

  • Cons: They may not be as effective at removing stubborn grime.

Safety measures:

  • Deactivate the solar panel system before cleaning.

  • Use a long-handled roof brush or sponge so you don’t need to climb onto your roof

  • If extra length is needed, utilize a sturdy ladder, a safety harness and always have someone spot you.

  • Wear rubber-soled shoes for better grip.

Professional services

When to consider professional solar cleaning:

Depending on the size of your home and the orientation of your panels, you may find that it’s best to bring in professionals to clean the panels versus using a long-handled brush to tackle the job yourself. Here are some other situations where it may make sense to bring in the pros:

  • Post-storm or natural disaster

  • After a significant drop in panel efficiency

  • Annually, for a thorough cleaning, if you live in a dry or dusty area

Cost range:

Prices range from $100 to $300, depending on system size and location (may differ significantly by region).

Automated cleaning systems

Types of automated systems:

  • Robotic cleaners

  • Sprinkler systems

  • Electrostatic cleaning

Cost and efficiency:

  • Systems range from $400 to $1,200.

  • Up to 95% efficiency, reducing manual labor.

Using robotic systems

These advanced systems clean panels autonomously. Should you invest in a robotic solar panel cleaner for automated cleaning? For most homeowners, it’s likely not necessary, but it’s still interesting to see the technology advancements here!

  • Pros:  Efficient cleaning without manual effort.

  • Cons: High initial cost, may need an external power source.

Geographic and placement suitability:

  • Ideal for large installations or dust-prone areas.

  • Not advised for slanted or vertical panel placements.

Waterless vibration

Employs sonic vibrations to dislodge dust and debris. If you’re interested in this solution, opt for a waterless vibration cleaner.

  • Pros: Saves water, highly effective.

  • Cons: Limited availability, potentially expensive.

Quick take: Your approach to cleaning solar panels depends on various factors like budget, time, or environmental considerations. 

Tips for cleaning solar panels

Cleaning your solar panels involves not just dirt removal but also safety and efficiency. Here are some tips to optimize your cleaning efforts:

Safety considerations

  • Always have a partner for support.

  • We advise against getting up on your roof to clean your solar panels whenever possible, but if you feel that it’s necessary, opt for a safety harness or hire a professional solar panel cleaning service.

Eco-friendly cleaning solutions

  • Choose biodegradable soap.

  • Collect rainwater for use when feasible.

Frequently asked questions: Cleaning solar panels

What is the best thing to clean solar panels with?

Soft-bristle brushes and plastic-blade squeegees are ideal. Attach them to a long pole for hard-to-reach areas.

What cleaning products can I use on solar panels?

Mild, biodegradable soap is recommended. Avoid abrasive cleaners or chemicals. Vinegar and water mixtures are also eco-friendly.

Can I use Dawn dish soap to clean my solar panels?

Yes, Dawn dish soap is gentle, effective, and biodegradable. Rinse thoroughly to avoid residue affecting performance.

Can I just rinse my solar panels?

A simple water rinse removes loose dirt but may not eliminate stubborn grime. For thorough cleaning, soft-bristle brushes and mild solutions are advised. However, rinsing serves as good maintenance between deeper cleanings.

Should you use Windex on solar panels?

Avoid Windex or ammonia-based cleaners. These can leave residues affecting panel performance.

How to clean solar panels from snow?

Snow can significantly reduce the efficiency of your solar panels. In order to clean snow from your panels, start by shutting off your system. Then, use a soft roof rake with a plastic blade to remove snow. Start from the lower edge and work upwards, applying minimal pressure. For hard or icy snow, natural melting is safer to prevent damage.

How to clean solar panels on the roof automatically?

Automatic systems, often using sprinklers or robotic brushes, offer a hands-off approach. While convenient, they can be costly and require upkeep. Research to find a system that fits your specific needs and location.

Can you clean solar panels with bleach?

Avoid bleach or harsh chemicals, as these can damage solar cells and reduce efficiency. Opt for mild, eco-friendly solutions for best results.

How do professionals clean solar panels?

Professionals often use deionized water systems and specialized solutions. They may also use extendable brushes for hard-to-reach areas and drones for pre and post-cleaning inspections.

What should you not do when cleaning solar panels?

  1. Don't use abrasive tools: Hard bristles can scratch panel surfaces.

  2. Avoid harsh chemicals: Avoid bleach and ammonia-based cleaners.

  3. Don't use pressure washers: High-pressure hoses can damage the solar cells.

  4. Avoid cleaning during hot days: Sudden temperature changes can stress panels.

  5. Don't walk on the panels: This could break the glass or damage cells. In fact, we advise that you don’t get on the roof at all!

Maintenance and monitoring: Sunrun's comprehensive approach to solar efficiency

One of the best ways to understand the performance of your solar panels and how things like dirt may impact output is to use a monitoring system. After installing your solar panels, the journey to efficient and sustainable energy doesn't stop. Sunrun offers a robust maintenance and monitoring package to ensure your solar system is always at its best:

Sunrun's 24/7 system monitoring

Sunrun employs best-in-class monitoring technology that proactively informs us of any possible issues with your solar system. This ensures that your system is always operating at peak performance. You don't have to worry about constantly checking your system's status; Sunrun does it for you.

Comprehensive warranty and service coverage

Sunrun offers a 25-year coverage on all their equipment. This includes free equipment replacement and system repairs, including all parts and labor. Sunrun also guarantees that their roof penetrations are watertight for a full decade.

Insurance for your solar panels

Sunrun's monthly lease plans come with full insurance coverage to protect your entire solar system against theft or damage. This means you're covered in case of unforeseen circumstances.

Dedicated customer support

Every Sunrun customer receives dedicated support from the initial design phase to powering on your system. We walk you through every step and even provide email updates on your project's progress.

What if something breaks?

With Sunrun, you pay nothing for repairs. We cover your system’s maintenance and take care of all the paperwork, scheduling, and more.

Quick tip: By choosing Sunrun, you're opting for a worry-free, comprehensive approach to solar energy. From monitoring to maintenance, Sunrun has you covered.

Government incentives for panel maintenance

Did you know that some jurisdictions offer incentives for proper solar panel maintenance? These can come in the form of tax credits or even grants. It's a win-win: you save money, and the planet benefits from more efficient solar energy production. 

  • Quick tip: Research local and federal government incentives for solar panel maintenance. Apply for any that you qualify for.

The future of solar panel cleaning: What's on the horizon?

Solar panel technology is always evolving, and so are the methods for keeping them clean and efficient. 

In the future, we may see cleaning drones and advanced coatings repelling dirt. As tech advances, expect more efficient, less labor-intensive cleaning methods. Imagine a future where your solar panels clean themselves or where cleaning services use advanced robotics to do the job in half the time.

  • Quick tip: Keep an eye on emerging technologies and methods. Be open to changing your cleaning routine as new options become available.

So, there you have it—a deep dive into the world of solar panel maintenance and monitoring, environmental considerations, and a sneak peek into the future. By staying informed and proactive, you can ensure that your solar panels will continue to provide efficient, eco-friendly energy for years to come. Let's quickly recap what we've covered:

  • Why clean solar panels?: Dirty panels can reduce your system's efficiency and, consequently, your energy savings.

  • When and how to clean: Timing is crucial. We discussed various methods, from manual cleaning to automated systems and even specialized cleaning solutions like nanoparticle coatings.

  • Safety and eco-friendly practices: Prioritize plant-based cleaners with safe ingredients for your family's health. Harsh chemicals harm more than dirt. Look for third-party certifications like Safer Choice—they take the guesswork out of going green.

  • FAQs: We tackled common questions about cleaning materials, techniques, and special circumstances to give you a well-rounded understanding.

  • Maintenance and monitoring: Beyond cleaning, regular maintenance and monitoring are vital for optimal performance. With 24/7 cutting-edge monitoring technology from Sunrun, we don’t just keep an eye on things; we ensure your system's optimal performance around the clock.

The key takeaway here is that regular maintenance goes hand in hand with solar panel efficiency. It's not just about cleaning your panels but also about monitoring their performance, following manufacturer guidelines, and staying updated on new cleaning technologies and methods.

At Sunrun, we simplify this process for you. Our expert Solar Advisors guide you through every facet of solar care, from understanding how to optimize your system's efficiency to staying updated on the latest cleaning technologies and methods.

As the nation's #1 home solar & battery installer, Sunrun offers dedicated support from the initial design of your custom-tailored solar system to the moment it powers on. With Sunrun, you're not just installing solar panels; you're investing in a stress-free, efficient, and sustainable energy solution for your home.

And remember, by taking a proactive approach to maintenance, you're not just extending the life of your solar panels—you're also maximizing their efficiency, which translates to more energy produced and potentially more money saved. Plus, you're contributing to a greener, more sustainable future for us all.

Armed with the right knowledge and tools, your investment will pay off in the most efficient, eco-friendly manner possible.

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