You’ve invested in solar panels for your home or business, making a smart choice for the environment and your wallet. It’s true that your solar energy system is a powerful asset, but its performance is largely determined by one factor: sunlight. When dirt, dust, pollen, and bird droppings accumulate on the surface of your panels, they act as a barrier, blocking the very thing that makes them work.
Despite what it may seem, it’s important to perform a thorough cleaning every year to keep the system running well. Neglecting this simple maintenance task can significantly reduce your energy output and increase your electric bills. So, what is the best way to clean solar panels? You’ll find everything you need to know here, from “why” and “when” to “pros and cons” of DIY and professional cleaning.
How Dirt Steals Your Energy
To understand why cleaning is so important, let’s talk about the impact of “soiling”—the industry term for dirt accumulation on solar panels. Solar panels are designed to capture photons from sunlight and convert them into electricity. Even a thin layer of dust can partially block these photons, reducing the number of electrons that can be excited within the photovoltaic cells.
According to studies by the National Renewable Energy Laboratory (NREL) and other research bodies, dirty solar panels can lose anywhere from 15% to 25% of their efficiency. In some extreme cases, with heavy soiling from bird droppings or industrial pollutants, this loss can soar to 30% or more. This isn’t just a minor dip in performance; it’s a tangible financial loss that adds up over the lifespan of your system.
Common Culprits of Solar Panel Soiling:
- Dust and Airborne Pollutants: This is the most common form of soiling, particularly in urban areas with vehicle emissions or rural areas with agricultural dust.
- Pollen: During spring and summer, a thick, yellow layer of pollen can settle on panels, creating a stubborn film that rain often can’t wash away.
- Bird Droppings: A single, large bird dropping can cause a significant “hot spot” or “partial shading” effect. This is particularly problematic because if one cell in a panel is shaded, it can dramatically reduce the output of the entire panel.
- Tree Sap and Leaves: If your panels are located near trees, falling leaves and sticky sap can create a difficult-to-remove residue.
- Hard Water Stains: If you’ve tried cleaning your panels yourself with tap water, you may have noticed stubborn streaks. These are caused by minerals like calcium and magnesium, which can leave a residue that further hinders sunlight absorption.
How Often Should You Clean Your Solar Panels?
The frequency of cleaning depends on several factors, but a good general rule is to have your panels cleaned at least once every 6 to 12 months.
However, you should adjust this schedule based on your specific location and circumstances:
- Location: If you live in a rural area near farmland or in a desert region, you may need to clean your panels more frequently due to a higher concentration of dust. Conversely, if you live in a city or a coastal area, a higher level of traffic emissions or sea salt can necessitate more frequent cleaning.
- Weather: A good amount of rainfall can help rinse off loose dirt, but it won’t remove stubborn grime or hard water stains. If you experience long dry spells, a cleaning may be necessary to restore efficiency.
- Panel Tilt: The angle of your panels matters. Panels with a steeper tilt are better at shedding dirt and debris with the help of rain. Flatter panels will require more frequent cleaning.
- Monitoring Your System: Many modern solar systems come with a monitoring app that allows you to track your energy production. If you notice a sudden and unexplainable drop in efficiency, it’s a strong sign that your panels need a clean.
The Great Debate: DIY vs. Professional Solar Panel Cleaning
When it comes to cleaning your solar panels, you have two primary options: doing it yourself or hiring a professional. While DIY might seem like a cost-effective solution, it’s crucial to understand the risks and benefits of each approach.
DIY Solar Panel Cleaning: The Pros and Cons
For those who are confident working at height and have easily accessible panels, a DIY clean can be a viable option.
Pros of DIY Cleaning:
- Cost Savings: The most obvious benefit is that you save money on professional service fees.
- Control: You can clean your panels whenever you feel they need it, giving you complete flexibility.
The DIY Process (If Done Correctly)
- Safety First: Always prioritize your safety. If your panels are on a rooftop, consider whether it’s safe to access them. Never attempt to clean panels on a hot day, as cold water on a hot surface can cause thermal shock and crack the glass. The best time is early morning, late evening, or on a cloudy day.
- Power Down: Before you begin, switch off your solar panel system to eliminate any electrical risks.
- Gather Your Tools: You will need a soft-bristled brush, a squeegee, and a garden hose with a low-pressure nozzle.
- Use the Right Solution: Use a small amount of a gentle, biodegradable, and non-abrasive soap mixed with pure, deionized water. Avoid harsh detergents, abrasive chemicals, or window cleaners, as these can leave a film, cause streaks, or even damage the panels and void your warranty.
- Gentle Cleaning: Begin by rinsing the panels with the hose to remove loose dirt. Then, use your soft brush to gently scrub away any stubborn grime. Finally, rinse thoroughly and use the squeegee to remove excess water and prevent spots.
Cons and Risks of DIY Cleaning
- Safety Hazards: Climbing onto a roof, especially with water, is extremely dangerous. Without proper training and safety equipment, the risk of a fall is very high.
- Damage to Panels: Using the wrong cleaning tools (e.g., a hard-bristled brush, a pressure washer, or a harsh chemical cleaner) can scratch or corrode the protective glass on your panels. Even micro-scratches can significantly reduce their long-term efficiency.
- Warranty Issues: Many solar panel manufacturers have strict guidelines for cleaning and maintenance. If you use an unapproved cleaning method or product, you could inadvertently void your warranty, leaving you financially exposed if a problem arises.
- Ineffectiveness: Without a pure water system, using regular tap water can leave behind mineral deposits (hard water spots) that can be as bad as or even worse than the original dirt.
Professional Solar Panel Cleaning: A Safe and Effective Choice
Hiring a professional is, for most people, the safest and most effective way to maintain your solar investment. A professional service provides peace of mind and guarantees a superior result.
The Benefits of Professional Cleaning
- Safety and Expertise: Professional cleaners are trained, insured, and equipped with the right safety gear to work at height. They understand the risks and have procedures in place to mitigate them.
- Specialised Equipment: The best professional cleaners use state-of-the-art pure water systems. This process involves deionizing and demineralizing water, which ensures a completely spot-free and streak-free finish without the need for chemicals. This is the single most effective way to clean solar panels and prevent future soiling.
- Maximum Efficiency: By removing all forms of grime, including hard water spots, a professional clean ensures your panels are operating at their absolute maximum efficiency, generating as much electricity as possible. This increased output often pays for the cost of the cleaning service itself.
- Warranty Protection: Professional companies use industry-approved methods that will not void your manufacturer’s warranty. This is a critical factor in protecting your long-term investment.
- Visual Inspection: During the cleaning process, a professional will also conduct a visual inspection of your solar system, checking for any cracks, loose wiring, or other potential issues that you might not have noticed from the ground. Catching a small problem early can prevent a major, costly repair down the line.
The decision to clean your solar panels yourself or hire a professional comes down to a balance of safety, effectiveness, and convenience. For a homeowner, the risk of injury and the potential for damaging your expensive solar panels often outweigh the small cost savings of a DIY clean. A professional cleaning service not only restores your system’s efficiency but also provides a level of care and expertise that ensures your investment is protected for years to come.
Newcastle District Cleaning provides solar panel cleaning in Newcastle upon Tyne and surrounding cities, using advanced pure water systems to ensure a safe, effective, and streak-free clean for your home or business.