Should I be cleaning my solar panels?
You’ve made the decision to go solar. Great! Now you want to learn how to make the most of your investment. In the winter, snow and ice are the biggest enemy of solar generation, but the warm weather has its own challenges keeping you from reaching your maximum efficiency: dust.
In fact, dust, dirt, moss, bird droppings, and anything else that accumulates on top of your panels can have a significant impact on how much power you are producing. A 2017 study from Duke University reported on by Popular Mechanics showed that dirt and dust can reduce the efficiency of solar arrays by up to 25%. Depending on the size of your residential array, this could represent a loss of hundreds or thousands of dollars in generation revenue over the course of a year. In the worst conditions in very dusty environments, primarily in arid regions of the world, the study found that…
“…for solar panel surface cleanings that occur every 20-30 days, power generation increases by on average 50% after each cleaning.”
How do I know if my panels need cleaning?
Here’s the good news: in our climate in south-western Ontario, wind and rain wash away much of the dust and debris that accumulates on solar arrays. Most residential solar arrays are roof-mounted and are not exposed to a lot of dust. Many of our residential customers have had their solar arrays operating for more than a decade without any cleaning, and they have not seen a substantial decrease in production due to dust.
However, you live downwind of farming or a gravel pit, or you have a ground-mounted solar array, dust accumulation may be costing you Watts. A visual inspection of your panels is usually enough to determine if they need a cleaning. Panels should be black or blue and shiny. If they look brown and dull, you could benefit from a cleaning. If you are monitoring your production through a program like mySolarEdge of the Enphase App and you notice a gradual decline in your power production year over year, it may be worthwhile contacting Merlyn Power to find out why. Regular cleaning could be the solution.
Do’s and Don’ts
If you inspect your panels and notice that they’re looking a little dirty, or you just want to get the maximum efficiency out of your system, here’s the dos and don’ts of solar panel cleaning:
DO
- rinse panels with a stream of water from your garden hose
- contact your installer or your panel manufacturer for the proper cleaning product to use. Different manufacturers recommend different products, but typically a mild plant-friendly detergent
- lightly scrub the panels and rinse the dirt away with water
- be sure you are using your ladder correctly and safely, and using any necessary safety equipment before climbing your roof. If you don’t have the equipment and know-how, hire a professional!
DON’T
- wash your panels with a pressure washer as this can damage the panels and electronics mounted underneath it
- spray cold water onto hot panels. In extremely hot weather this can cause the glass covering the panels to crack
- use chemicals or harsh detergents that are not safe for plants or wildlife
- climb on a ladder or roof without proper training and safety equipment
We hope this quick guide has helped you to understand how to get the most out of your solar installation. If you have any questions or concerns about the operation of your solar array, or if you are interested in getting started with a new installation, contact us.