Since SunPower panels can be one of the most efficient panels on the market they’ll make more energy than competing panels in a variety of low-light situations, but any panels covered with too much dirt or debris will produce less power.
In most cases, the loss of power isn’t significant — maybe 1 to 4.7 percent. But one study found that long-term dirt buildup can reduce a solar panel’s electricity production by as much as 20 percent.
How to Clean Your Solar Panels
The good news is that seasonal rain and snowmelt usually washes off any dirt that may have accumulated. But if your area receives very little precipitation and has dusty, windy weather, you may need to occasionally clean your panels. Some homeowners are able to do this themselves or they may choose to have them professionally cleaned.
Fortunately, cleaning solar panels is easy for ground-mounted systems, or for rooftop solar systems on a typical one-story house. We recommend homeowners use a soft-bristle brush with an extended handle, like the type used to clean off an RV. And don’t forget to choose an environmentally friendly soap.
If the panels are hard to access, such those on a two-story home, we suggests buying a high-pressure hose nozzle with an attachment that holds soap. These can be found at any home maintenance store. Find a safe place to stand, spray soapy water on the panels and then quickly rinse them off.
It’s really that simple!
Do-it-yourselfers should keep some other things in mind:
- As a rule, stay on the ground. Never get up on your roof without a secure ladder and proper fall-protection equipment.
- Avoid using hard, or mineral rich, water. It can damage panels over time. If your area only has hard tap water, you can buy an inexpensive water-softening hose attachment to filter out minerals. Otherwise, you can use distilled or de-ionized water.
- Use soft brushes and squeegees. Don’t use abrasive brushes, pads or powders.
- Clean early in the morning or in the evening when the panels are cool. During the heat of the day, water and soap can evaporate quickly, which risks smearing the soap and dirt.
- When using a high-pressure water nozzle, don’t get close to the panels. While they’re extremely durable, you don’t want to damage them.
Of course reach out to us anytime if you have any maintenance questions!