why Solar Panels Need To Be Cleaned (Important Maintenance)

Like your car that needs a regular oil change and service to maintain its operational condition, solar panels also need to be cleaned regularly to maintain the efficiency of the supply and prolong your PV system’s life. It makes sense to maintain it as you would with any reasonable investment.

Based on the environment you live in, you may need to clean your solar panels once a month or only once every six months, especially if there is dust, you have trees that drop leaves, and have many birds in your area as they are one of the biggest threats to your PV system’s sustainability.

There are areas regarding cleaning solar panels that you need to address :

  • What causes solar panels to get dirty
  • How much energy could you lose if you don’t clean your panels
  • What to use when cleaning solar panels
  • When to clean solar panels
Solar Panels Being Cleaned
Solar Panels Being Cleaned

why Solar Panels Need To Be Cleaned

The glass and the coating are critical to ensure the panels’ efficiency, which is why they need to be cleaned regularly. Solar panels are made from silicon (sand) and layered in silicon wafers with a conducting material (usual boron).

The wafers are then compacted into a matrix configuration, and glass is added with an anti-reflective coating that encourages the absorption of sunlight.

Electricity is generated as the silicon looks to balance its electrons as the sunlight strikes the panel.

What Causes Solar Panels To Get Dirty?

Since most solar panels are installed on the roof at an angle to achieve optimum solar exposure, dust, dirt, leaves, and bird droppings can accumulate on the panels over time.

There is an argument that they would be cleaned after each rain, which is true, but if rain were an effective cleaner, car washes would be out of business during the rainy seasons!

Flat solar panels would need more cleaning and maintenance than tilted ones as they would not benefit from the rain washing the debris off.

This is because rainwater has fine dust that is dissolved and then left behind when the water evaporates. If you have just washed your car and had it rain, you will see that fine layer of dust on your windows afterward.

If you live by the coast, the saltwater vapor that settles on everything will also settle on your panels, and you’d need to clean them possibly every month to maintain the level of light absorbed.

The same happens with solar panels, and while you may not think this could reduce your solar panels’ operational efficiency, that’s not entirely true either.

How Dirt, Dust, And Bird Droppings Affect Your Solar Panels

An ongoing accumulation of dust and dirt on the panel surfaces will cause less and less light to reach the PV cells, and over time ( see below), this could snowball into a significant loss of energy.

Bird dropping is one of the biggest enemies of solar panels as not only would they cover the surfaces, but if it got into the microinverters (if you have them), it could cause the units to show a no current flow.

Workman Cleaning Solar Panels. - Sol Voltaics: Solar Panel Information
Workman Cleaning Solar Panels.

How Much Energy Could You Lose With Dirty Solar Panels?

A few arguments say that dirty solar panels only incur negligible energy losses of around 5% when dirty. Still, that energy loss could reach as much as 35% over two years!

Over eight quarters without regular cleaning, you would lose about 5% per quarter, and if you lose energy, you are losing money!

Regular cleaning, in most cases, is about twice a year, but if your area is prone to dust and other debris, you may need to do that every quarter.

Solar Panel Dusty And Dirty After A Long Summer Without Rain And In Need Of Cleaning. - Sol Voltaics: Solar Panel Information
Solar Panel Dusty And Dirty After A Long Summer Without Rain And In Need Of Cleaning.

What To Use When Cleaning Solar Panels

One of the cardinal rules when cleaning solar panels is don’t use any detergent stronger than dishwashing liquid. This is all you need to get your panels back to the super clean condition they were when first installed.

More potent chemicals like bleach could quickly leave indelible marks on your panels, affecting their efficiency.

Another question is whether you can use a high-pressure washer on your panels, and again, a standard hosepipe or bucket of water is more than enough. High pressure can potentially dislodge components in the system.

All you need is a sponge, even for those problematic bird stains, and a cloth for the rest. As an added tip, try using a long-handled sponge or similar tool to clean your panels, making accessing the whole surface more controllable.

Red Microfiber Cloth Cleaning Solar Panels Or Photovoltaic Module. - Sol Voltaics: Solar Panel Information
Red Microfiber Cloth Cleaning Solar Panels Or Photovoltaic Module.

When To Wash Your Solar Panels

You might think that you can wash your panels anytime. Get on the roof or ladder with your bucket of detergent and hosepipe, and away you go! But, like most things in this life, nothing is ever that simple.

Remember that solar panels get very hot, so cleaning them during the day’s heat may seem like a good idea, but it’s not. Look to clean your solar panels in the morning before the sun gets high or in the later afternoon after the perihelion is over.

The panels will be cooler, and so will the roof temperature, and this will be a lot more comfortable and safer for you to clean your panels and then allow them to dry.

Hire A Professional Cleaning Service To Wash Solar Panels

Another option may be to spend a little money and hire a company specializing in cleaning solar panels. Many installers often have this service available to their customers or subcontracting specialists.

There are good reasons for doing this, including that your panels will get adequately cleaned, and any issues found can be fixed or remedied without delay.

Also, professional cleaners will have specially formulated detergents and cleaning equipment to ensure optimum results.

There have also been some innovations produced regarding the cleaning of solar panels. One of those is dirt and dust-resistant coating that prevents accumulation and coagulation of dust and dirt on the panels, and they are washed clean after the rain or with a hosepipe.

Another one that may seem like science-fiction is robotic cleaners that work at night and use a combination of compressed air and soft brushes to clean and polish those surfaces to a factory state.

General Solar Panel FAQ

What Problems Do Solar Panels Solve?

In environmental terms, solar panels can potentially solve a handful of problems, including;
1. Air pollution
2. Water pollution
3. Greenhouse gases
4. Reduction in fossil fuel use

For individuals, solar energy allows you to become completely self-sufficient when it comes to your electricity needs and can save you a lot of money in the long run.

What Are 3 Important Uses Of Solar Panels?

The three most important uses of solar panels are;
1. Solar electricity. This can be used to power almost any appliance in your home, including TVs, computers, and fridges.
2. Lighting. In addition to the use of low-power, LED lightbulbs, solar panels can provide an efficient, low-cost, and environmentally friendly way to provide lighting to homes. 
3. Portable solar. In our modern, always-connected lives, our phones, tablets, and computers are almost always with us, and all run on batteries. Portable PV chargers can help keep our batteries topped up no matter where we are, as long as there is some sun to charge them.

Do solar panels give you free electricity?

Once the cost of the array is paid in full, the energy it produces is free. There are ongoing maintenance costs, too, such as annual panel cleaning, etc. 

How much will my electric bill be with solar panels?

Suppose your solar array includes a solar battery backup system, and it is large enough to fully cover your energy usage per day. In that case, your monthly electric bill will be next to zero dollars, even with a grid-tied system. 

If your solar array does not include a solar battery backup system, then at night, your house or business will use grid electricity. That cost will vary but expect to pay from 1/3-2/3 of your average electric bill, and that cost will fluctuate seasonally. 

Do you save money with solar panels?

The simple answer is, Yes, you save money with solar panels. There is an initial upfront cost, but since solar panels are warrantied for 25 years, you will save money over time. You will also begin to see monthly savings in energy bills, but there are other ways that solar panels pay you back. Those include:
1. Adding value to your home or commercial building 
2. Monthly decreases in energy costs
3. The ability to add more energy appliances without increased monthly costs
4. The potential for tax credits for going solar

Can solar panels power a house 24-7?

Most definitely! Solar panels can certainly power a house 24-7, with the addition of a high-quality inverter and a suitable battery bank, of course. To power, a house under normal usage will require a massive solar array, though, and there will be a very expensive initial financial outlay.

Do I need to tell my energy supplier I have solar panels?

This depends on where you live, but in most cases, it’s not necessary to inform your energy supplier that you have solar panels. That said, you may be producing excess power with your solar system, in which case you may be able to sell that excess power back to energy companies.

In this case, you’ll naturally need to be in contact with them. 

What Are Solar Cells Known as and Why?

Solar cells are also called photovoltaic (PV) cells. They are called so because the term ‘photovoltaic’ literally means light i.e. photo and electricity i.e. voltaic.

These cells generate electricity through the photovoltaic effect. This effect basically causes the generation of free electrons from the semiconducting silicon material of the solar panel when sunlight hits its surface.

What Type of Solar Panels Are Most Efficient and Why?

There are currently three types of solar panels available in the market that are:
1. Monocrystalline
2. Polycrystalline
3. Thin-filmed

Among these, monocrystalline solar panels are known to be the most efficient among all others.

Does heat enter your home through the roof?

Absolutely. Heat enters your home through your roof, and on a hot day your attic can get up to 150 degrees Fahrenheit or more. Through conduction, heat from the sun warms your roof which then warms your attic and the rest of your home.

Sol Voltaics is an affiliate and an Amazon Associate, we earn from qualifying purchases - at no extra cost to you.


Sol Voltaics Logo Icon green white