Any obstruction of the flow of sunlight to the panels' photovoltaic (PV) cells may reduce their electricity generation's efficiency. 

But experts disagree profoundly as to the significance of this effect.

How Much Energy does Solar Roof Cleaning Save?

Some estimate the energy lost at as much as 5% a quarter - a potential total loss of as much as 35% by the end of the second year without cleaning.

Others believe that wind and rain's natural action means that no temporary accumulation of dirt or dust will ever reduce your energy output by more than about 5%.

How Dirt and Dust Accumulate

Dirt and dust naturally build up quickly on panels installed close to busy roads, airports, or manufacturing centers. And the particulates deposited in these areas of poor air quality, high carbon emissions, and industrial pollution tend to be sticky and much less easily washed away by rain. 

Pollen, bird droppings, and falling leaves may also contribute significantly to the problem, particularly when installations are close to trees or bushes. 

In relatively dry regions such as Arizona, Nevada, and California, rainfall may be neither frequent nor heavy enough to clean panels adequately.

How the Florida Climate Helps – and How it Doesn’t

But here in Florida, frequent heavy rain will do most of the work required to keep your panels clean. 

That said, it’s also important to pay attention to the roof's condition surrounding your solar panels. The same tropical downpours that wash clean your panels can also be very damaging to roof structures. Simultaneously, the warm and humid conditions usual in Florida encourage the rapid growth of algae, mold, and mosses. 

Left unchecked, these can grow into the tiles, clay, and wood that comprise the very structure of your roof, significantly shortening its life and potentially undermining the fittings that support your solar panels. Worse, algae and moss are also very attractive to insects, small animals, and birds, which will cause further roof and panel damage.

How Often Is Cleaning Required?

Experts recommend a thorough clean of your roof and solar panels at least once every two years. And, depending on the age, general condition, and location of your property, an annual or even six-monthly clean may be indicated. 

If you live in one of the many deed-restricted, gated, condo, or homeowner association properties common in Florida, then the frequency and type of roof cleaning might be implemented by the association. There are some contractors who only offer their services to these kinds of communities. But, at the very least, your community should be able to advise you on the best practices to be observed regarding your solar panels. 

Individual, private householders, though, essentially have to decide whether to hire a professional contractor or to carry out the work of cleaning their roofs and panels themselves.

Safe and Effective Cleaning - Some General Precautions

Depending on the size and type of property, it may be possible to self-clean, but a less frequent cleaning schedule means that it may be more cost-effective –and certainly safer - to use a professional service. ​

That said, the health, integrity, and appearance of your roof are essential to the safe enjoyment and resale value of your home.

So, before hiring any contractor, you should take care to obtain independent references, photos of completed work, and certificates of comprehensive liability insurance.

And, as to the carrying out of the work, you should be sure to take these further precautions -

  • do not use - and don’t allow your contractors to use – any kind of high-pressure wash, which may damage both solar panels and roofs;
  • do not use - and don’t allow your contractors to use – any type of bleach or chlorine-based cleaning material; many far less damaging eco-friendly solvents are now available, and regular dish soap will work just fine;
  • do not use – and don’t allow your contractors to use – any kind of abrasive brush; soft sponges will clean more than adequately without scratching or damaging roofs or panels;
  • if tackling the clean yourself, hose the panels from the ground instead of standing on the roof. Never walk or lean on the panels, it can cause permanent damage. Washing your solar panels will make your roof wet and slippery.

We hope this blog answers your questions regarding cleaning your solar panels. If you have any further questions contact us. Don't expose yourself to any risk.  If you have any doubts about your ability to safely clean your panels, hire a professional.

Vinyasun is your best local solar energy contractor. We are your local experts in the Tesla Powerwall, SunPower, and every aspect of solar installation contracting.

Request a quote online