Solar panels work best when they’re clean, but many people don’t realize how much dirt can mess up their efficiency. Dust, bird droppings, and grime can block sunlight, leading to lower energy production.
Keeping your panels in good shape doesn’t have to be complicated. Follow these dos and don’ts to avoid damaging your investment and keep everything running smoothly.
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Things to Do
| Action to Take | Why It’s Important | Best Practices |
|---|---|---|
| Use Soft Tools | Prevents scratches on panels | Use a soft brush, sponge, or cloth |
| Clean with Water | Avoids damage from chemicals | Use plain water or mild soap |
| Clean in Cool Weather | Reduces risk of streaks | Clean early morning or late afternoon |
| Inspect Panels Regularly | Detects dirt buildup early | Check for dust, bird droppings, or debris every few months |
| Follow Manufacturer Guidelines | Prevents warranty voids | Check your manufacturer’s instructions |
1. Use Soft Tools
Use soft brushes, sponges, or cloths to clean your solar panels. Hard bristles or abrasive materials can scratch the panel’s surface, lowering energy production. A soft squeegee works well to remove excess water and dirt without causing any damage.
However, keep in mind that you should always turn off the panel before cleaning. As Hannah Glenn explains in her article on Solar.com, refer to your panel manufacturer’s instructions before shutting down the system for cleaning, if required. Avoid going on the roof for cleaning, as it poses risks to both you and your panels.
2. Clean with Water
Plain water is safe for solar panels and effectively removes dirt and debris. If needed, use a small amount of mild dish soap to tackle stubborn spots like bird droppings. Be sure to rinse thoroughly to prevent streaks.
Also, learn more about monofacial and bifacial solar panels.
3. Clean in Cool Weather
Clean panels in the early morning or late afternoon when they’re cooler. Cleaning in direct sunlight can make the water evaporate too quickly, leaving streaks. This also helps avoid accidental damage from working on hot panels.
4. Inspect Panels Regularly
Regular inspections help spot dirt before it affects performance. Check for dust, grime, or bird droppings every few months. If you live in a dusty area, you may need to inspect and clean more frequently.
According to The National Renewable Energy Laboratory, Dust accumulation on solar panels can reduce efficiency by as much as 7% in parts of the U.S. and up to 50% in the Middle East.
5. Follow Manufacturer Guidelines
Always follow your manufacturer’s cleaning recommendations to avoid voiding the warranty. Using the wrong cleaning method or tools can lead to damage that might not be covered.
Things to Avoid
| Action to Avoid | Why It’s Harmful | Better Alternatives |
|---|---|---|
| Using Pressure Washers | Can damage solar panels | Use a garden hose with light pressure |
| Harsh Chemicals | Damages protective coating | Use plain water or mild soap |
| Cleaning in Hot Sun | Causes water to evaporate too fast, leaving streaks | Clean in the early morning or late afternoon |
| Abrasive Tools | Scratches panel surface | Stick to soft brushes or sponges |
| Skipping Safety Precautions | Increases risk of accidents, especially on roofs | Always prioritize safety or hire professionals for roof-mounted panels |
1. Avoid Using Pressure Washers
High-pressure water can crack or damage solar panels. Stick to using a regular garden hose with gentle pressure to avoid causing harm.
2. Don’t Use Harsh Chemicals
Strong chemicals can damage the panel’s protective coating, reducing efficiency. Stick with plain water or mild soap to clean panels safely.
3. Don’t Clean in Hot Sun
Cleaning panels under direct sunlight causes water to evaporate quickly, leaving streaks. Choose cooler parts of the day, like early morning or late afternoon, to prevent this.
Experts from Cleaner Times explain that cleaning solar panels when they are too hot can cause cracking, especially if the surface temperature reaches 140–150°F.
4. Don’t Use Abrasive Tools
Abrasive materials, such as steel wool or hard-bristle brushes, can scratch the panel surface, leading to reduced sunlight absorption. Soft brushes or sponges are much safer for cleaning.
5. Don’t Skip Safety Precautions
Cleaning roof-mounted panels without proper safety equipment can lead to accidents. Always use safety gear like harnesses, or consider hiring professionals for hard-to-reach panels.
How Often to Clean Solar Panels?
The frequency of cleaning your solar panels depends heavily on where you live and environmental conditions. In general, cleaning every six months to a year is often enough for most residential installations.
However, this changes based on certain factors.
Location and Climate
If you live in a dry, dusty area, such as a desert, more frequent cleaning may be needed. Dust storms or heavy wind can cause significant grime buildup on your panels. Coastal areas, where salt can accumulate on the panels, also require more frequent maintenance.
In contrast, places with regular rainfall might not need as much cleaning since rain naturally helps to wash away some dirt. But relying solely on rain isn’t always effective, as heavier debris like bird droppings or pollen can remain even after a downpour.
Panels that are installed flat or at a low angle tend to collect more dirt and will need more regular cleaning than those at a steeper angle, which helps debris slide off.
Monitor the Energy Output
A noticeable drop in energy output often indicates the need for cleaning. Many solar systems come with monitoring apps or tools, so you can track your system’s performance. If you notice a significant drop in production without changes in weather or sun conditions, it’s time to check for dirt buildup.
Seasonal Changes
Certain seasons may require more frequent attention. For example, fall can lead to leaf buildup, while winter snow may cover panels. Snow usually melts and slides off naturally, but heavy snowstorms may call for manual clearing to prevent extended blockage.
DIY or Hire a Pro?
Choosing between cleaning your solar panels yourself or hiring a professional depends on a few things: panel location, your comfort level, and safety concerns.
When DIY Cleaning Makes Sense?
If your panels are easy to reach and you feel comfortable handling it, DIY is a simple, cost-effective option. All you need is a hose, a soft brush, or sponge, and water. Avoid fancy tools—just basic items from around the house.
However, safety is a priority. Only attempt this if the panels are accessible without getting on the roof. Working from the ground is always safer.
If you see dirt buildup but no major grime, a quick rinse with a garden hose might be all it takes. Panels mounted at angles tend to stay cleaner, as rain helps with basic cleaning. Inspect the panels regularly to know when more than a rinse is needed.
When to Hire a Pro?
For roof-mounted panels or hard-to-reach setups, hiring a professional is often the smartest move. Professionals have the right equipment to clean safely and thoroughly. If you’re uncomfortable with heights or climbing on your roof, leave it to the experts.
The average cost for professional cleaning services ranges from $150 to $500, or $10-$20 per panel, depending on size and location. It’s a small price to pay to avoid the risks of falling or damaging the panels.
Additionally, some solar panel warranties require professional cleaning at least once a year to stay valid. Professionals also inspect for potential damage, like cracks or bird droppings that could harm the panels over time. If you’re dealing with a large system or commercial installation, automated cleaning systems or hiring professionals regularly might make sense.
FAQs
Can dirty solar panels overheat?
Yes, when dirt and debris accumulate, solar panels can become less efficient and overheat. This happens because dirt traps heat, preventing proper cooling. Overheating can reduce energy production and shorten the lifespan of the panels.
Do solar panels need cleaning after heavy rain?
Rain helps clean some surface dirt but isn’t enough for heavy grime like bird droppings or built-up dust in dry areas. After heavy rain, it’s good to check your panels and do a light cleaning if you still see debris or streaks.
Is snow on solar panels a problem?
Snow usually melts off solar panels due to their dark surface, which absorbs heat. However, in heavy snowstorms or long periods of snow cover, you may need to remove snow manually to ensure your panels produce energy.
Can solar panels get damaged if I don’t clean them?
Dirt and grime can cause long-term damage if left untreated. They can scratch the surface, cause corrosion, or create hot spots that reduce efficiency. Regular cleaning helps prevent these issues.
Summary
Regular cleaning of solar panels ensures they operate at peak efficiency. Use soft tools, clean with water, and follow manufacturer guidelines to avoid damage. For hard-to-reach areas or roof-mounted panels, hiring a professional is the safest option. Keep an eye on energy output and the environment around your panels to determine the right cleaning frequency.
By sticking to these simple dos and don’ts, you’ll protect your investment and keep your solar system working smoothly.