How to Clean Solar Panels Safely and Easily

Cleaning solar panels on a regular schedule is essential to maximizing energy output, lowering power bills, and maintaining the panels for the long term. Dirty solar panels produce less energy than clean panels. This results in higher electricity bills because the solar supplement is reduced. Learn how to clean solar panels safely for crystal-clear front glass that generates as much power as possible.

Why You Need to Clean Solar Panels

When dust first settles on solar panels, there is a steep drop-off in energy output. If a great amount of dust is allowed to accumulate on the solar panels, the reduction in energy production can reach as much as 30-percent after just one month.

Investing in a solar panel system is expensive, and the system pays for itself only in the long term. Given that solar panels typically last about 25 years, you'll want to do everything you can to extend their lifespan and maximize their efficiency.

How Often to Clean Solar Panels

Solar panels should be cleaned every six months to once a year. Clean the panels once in fall and once again in spring.

Regional fires, pollen, high winds, or nearby construction work settle debris on panels, triggering the need for additional cleanings.

Solar panels mounted with a lower pitch or angle require more frequent cleaning than steeply-pitched panels.

When to Clean Solar Panels

Solar panels should be cleaned in the early morning when the front glass is still cool or in a later part of the day when the glass has cooled down. The temperature difference between the water and the glass may crack the glass. Also, water on hot glass evaporates before you've had a chance to squeegee or wipe it off, which can leave mineral deposits on the glass.

Solar Panel Cleaning Solutions

Most solar panel manufacturers recommend plain tap water or de-ionized water as the primary cleaning solution for solar panels. When coupled with a scrubbing brush, water is enough to remove dust, dirt, or other debris.

Ethanol, glass cleaner, or isopropyl alcohol can be used for spot-cleaning solar panels. Soap is generally not recommended for cleaning solar panels because of the residue it leaves behind. Avoid abrasive cleaners or alkali-based chemicals, including any ammonia-based solutions.

Removing Stubborn Stains From Solar Panels

Aggressive stains and deposits on solar panels may require different cleaning methods.

• Paint: Avoid scraping off paint drips and overspray from solar panels. Instead, use a paint removal agent to dissolve the paint, then wipe it off with a cloth. If that does not work, try lightly rubbing with bronze wool. Though bronze wool is a mild abrasive, using this may be necessary when other methods do not work.
• Pine sap or oil: Clean pine sap or oil off of solar panels with isopropyl alcohol.
• Bird droppings: Clean bird dropping off of solar panels by draping a hot, wet cloth over the droppings and letting the cloth rest for about a minute, then wipe it off.