Do I Need To Clean My Solar Panels?

Do I need to clean my solar panels?

Many Smart Solar Energy customers want to ensure that their solar PV panels operate at their optimum capacity. This helps boost the return on investment of your solar system and increases your solar electricity output. Sometimes, our customers ask us if they need to clean the panels on their solar power system.

In general, homeowners do not need to clean solar panels. However, dust and other particles can slightly decrease your solar electricity generation. Often, this can reduce the PV output by 5 percent. Typically, this isn’t worth cleaning the panels, but some homeowners do decide to clean them.

Solar Panels In The Sun

Determine What is Making Your PV Panels Dirty

Sometimes, it is merely dust that obscures your solar output. Dust is more likely to accumulate on solar panels in dry climates. For example, if tall deciduous trees surround your home, you might get leaves covering your panels, especially in the fall. Likewise, bird droppings are more common if you have trees nearby. Unfortunately, in some places in Oregon, it can be humid enough for moss to grow on solar panels, and this can’t merely be removed by rinsing with a garden hose. Also, ash can accumulate if there are a lot of wildfires in your area.

Typically, we get plenty of rain in the Willamette Valley to keep solar panels clean and working well. However, if you live in a dry part of Oregon with little rain, it might be worth rinsing the dust on your solar panels with a hose on rare occasion. This is an especially appealing option if you can hose off your panels while standing on the ground, and it doesn’t require a ladder.

Also, the flatter your solar panels are mounted, the more contaminants and even leaves can accumulate. If your panels are nearly flush on a flat roof, cleaning them will be more critical. However, if your panels are mounted on a steeply pitched roof, dust, pollen, ash, leaves, and other contaminants can easily slide off. 

Rinse Your Solar Panels if They Are Dusty

Merely rinsing your solar panels might be simpler, safer, and easier than cleaning your solar panels. If there aren’t things like tree sap and bird dropping, which require the panels to be cleaned with a cloth or soft scrubber, then rinsing the panels might be adequate. If you do rinse your panels, make sure you close any open windows before getting started.

If possible, just use the garden hose from the ground. Unfortunately, it might not be possible to spray off your panels from the ground if you have a 2 or 3 story home. In such cases, it might be essential to use a ladder.

ladder against a house

If you do use a ladder, make sure you follow essential ladder safety tips. First, select the right ladder for the job. Then, before you start using it, inspect it to make sure it’s in good condition. Next, set up the ladder with care and ensure that it’s stable. Next, face the ladder while climbing and descending it. Also, use both hands while climbing a ladder. Finally, be aware that your roof might be slippery or have a steep enough pitch that it is difficult to walk on.

Do not spray the panels with high-pressure jets or a pressure washer, as this could damage your panels. Instead, merely spray your panels with a garden hose or low-pressure sprayer and let them air dry.

home owner with a hose

Tips for Cleaning Solar Panels

If you determine that your solar panels have more than just dust, you might be considering cleaning them. Some roofs, such as flat roofs, can be safely and easily accessed without using a ladder. Whether it is worth cleaning your PV modules depends a bit on how difficult it is to access them. It is OK to leave a bit of dirt on the panels and have slightly lower electricity output. If you decide to take action, you can clean them using a mild soap and a cleaner.

Bucket and sponge

As always, safety first. It is critical to ensure that you can safely clean your panels. Depending on the layout of your home, this might be difficult. If so, just forgo cleaning them or hire a professional. Keep in mind that our solar panel installers are highly trained in roof safety and use harnesses. For some roof types, you might not be able to clean your panels effectively without safety gear and knowledge. Also, review the ladder safety tips above before getting started.

If you move forward with cleaning your panels, use a mild detergent and a soft brush, scrubber, sponge, or squeegee. Make sure that you don’t use anything that will scratch or damage your panels. This will create a long-term decrease in solar energy output so it is definitely something to be avoided.

First, wet the solar panels using a hose or low-pressure sprayer. Next, gently clean the panels with a sponge, rag, or squeegee. Finally, rinse your PV panels and allow them to air dry. You do not need to towel dry the panels.

Keep in mind that solar panels can get very hot on summer days. Therefore, it might be best to clean your panels in the early morning or evening when the sun isn’t as powerful.

If you have a ground-mounted solar system, it might be easier and safer to clean your panels, depending on the layout. Apply the same tips of using a gentle soap and soft cleaning tools.

Hiring Someone to Clean Your Solar Panels

Typically, it isn’t cost-effective enough to hire someone to clean your solar panels. However, if you do decide to hire someone, make sure they are bonded and insured.

Most homeowners forgo cleaning their solar panels. However, suppose you live in a dryer area of Oregon and are concerned about dust accumulation. In that case, the Smart Solar Energy team might recommend rinsing the solar panels if you can do so with a hose from the ground.

Smart Solar Energy customers often aim to maximize the efficiency of their solar PV panels, ensuring optimal performance for a better return on investment and increased electricity output. While generally, homeowners may not need to clean solar panels, the presence of dust and particles can marginally reduce electricity generation by approximately 5 percent. Factors such as dry climates, deciduous trees, bird droppings, and wildfires can contribute to panel dirtiness. In regions with little rain, occasional rinsing with a hose may be warranted, especially for panels mounted flat on roofs. The inclination of panels also affects the accumulation of contaminants, with steeper pitches naturally shedding debris. Rinsing panels is typically simpler and safer than a full cleaning process, but if cleaning becomes necessary, it’s advisable to use mild soap and soft tools, ensuring no damage to the panels. Safety precautions, including ladder usage, are crucial, and professionals may be needed for challenging roof layouts. While hiring someone for panel cleaning might not be cost-effective for most homeowners, those in dryer regions may consider rinsing panels as a preventive measure, with more extensive cleaning reserved for specific situations like moss growth or heavy soiling.

More extensive cleaning, with soap and sponge, is more involved and does require following safety precautions. In extreme cases, such as if moss grows on panels or is soiled with bird droppings, it might be worth taking such action.

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