Cleaning Your Solar Power System

May 22, 2024\Burlington, Washington, USA

Congratulations! You’ve invested in a solar system to power your home or business. 

You are seeing lower electricity bills and are more aware of the sunny days that power your building. Keeping those panels clean is an important part of ensuring you get the most from your solar system. Solar panel maintenance is relatively easy.

Tips and Tricks to cleaning solar panels

Cleaning Preserves Efficiency

Over time, panels get dirty, which impacts energy output. Solar panels are designed to perform at near full capability for more than 25 years, tending to only degrade less than 1/2 percent per year over their lifetime. Regular cleaning is recommended to ensure maximum performance. Often, rainfall can be an effective method of washing them. However, it is advisable, particularly in more arid climates where there is less rainfall, to clean solar panels 2-4 times a year.

Module cleaning should be done when solar irradiance is low: in the early morning, evening, or on cloudy days. Using the right tools and taking certain steps should avoid damaging the anti-reflective coating (ARC) that is on most panels. If the coating is damaged it will lower the effectiveness of the panel and possibly void the warranty.

When cleaning your panels, wear clean gloves. Avoid touching the glass with your bare hands and leaving dirt or fingerprints. Never use tools like blades, knives, steel wool, high pressure washers, abrasive brushes, cleaners, polishers, or substances that contain sodium hydroxide, benzene, nitro-thinners, or alkali chemicals. Any type of commercial glass cleaner containing isopropanol or ethanol can be used. A homemade option is a gentle, non-abrasive soap mixed with one part vinegar and eight parts water.  

First, shut off the system, something you can learn how to do from the manufacturer specifications. If you’re working on a rooftop array, consider using a hard hat, ladder support, and harness. Then whisk away debris like dust and leaves with a dry cloth, and gently scrape harder matter like dirt, bird droppings, and plant branches, with non-woven fabric or a hairbrush. Keep in mind that careful, focused cleaning is better than aggressive scrubbing that might scratch the panel. Follow up by spraying water (deionized or distilled is ideal but not mandatory) onto dirty regions, making sure to keep the pressure below 690Kpa (100 PSI). Use soap sparingly as it can leave a residue that leads to streaky panels which are unsightly and compromise the functionality of the panel.

If your panels have snow coverage you can either wait until it melts and falls off or gently remove it with a brush. Don’t remove frozen snow or ice – many modules can withstand heavy snow pressure up to 5400 Pascal (1 PSI).

Silfab Solar Install Top View

Know When to Hire a Pro

Your safety is the most important thing to consider. The safest option is to clean panels from the ground with extension tools. But if your system is two or three stories up, or set in a steep or slippery location, it’s better to hire a solar professional to avoid potentially serious injuries. Complex cleaning should be handled by a solar professional. Commercial arrays or those that are larger or situated on carports often require working with an experienced maintenance team.

Once a year, hire a professional to inspect the system to make sure it’s working properly and check for damage to the panels and components. The national average cost for an annual solar panel maintenance is between $150 and $300, something that is often covered by your installer warranty. Most manufacturers give equipment warranties that cover the panels against defects, equipment failure, and environmental issues. For example, Silfab Solar offers extended 25-year product and 30-year linear power warranties.

Monitor System Performance

Watch for system performance dips and changes in output levels. It’s important to regularly monitor your system output to measure the impact of cleaning. Some output fluctuations within the predicted range for your system are normal but if the panels are dirty, they will more consistently produce energy at the low end of the range. It can be helpful to review your energy bills before and after a cleaning to determine its impact.

Your Silfab Solar Warranty

Silfab Solar warrants that within the first year from the warranty start date, Silfab Elite BG, QM, QD, Silfab Prime QD, Silfab Commercial QM, XM product will have a power output that is 98%. of the nameplate maximum power output specified for the product (“Pmax”) in the case of mono-crystalline modules  (subject to the conditions and exclusions in the warranty). Silfab Solar further warrants that from years 2 through 30, degradation will not exceed .3% of Pmax per year for mono crystalline modules.

The good news is solar panels don’t need constant cleaning and other maintenance. However, removal of build-up and some monitoring is needed to keep them at peak performance and to avoid degrading in efficiency. If you take these simple steps to care for them each year, your panels will do an excellent job of producing all the clean energy and savings you expect.

Independent Solar Arizona Solar Power Install Shot (5)

Photo Credit: Independent Solar

Solar Calculator

Calculate your solar and energy bill savings based on your location, roof, energy rates and offers in your area.