Solar panel cleaning is an essential process to improve the efficiency of the panels. Solar panels convert the sunlight into usable electricity. The photovoltaic cells (PV cells) present in the panels help convert solar energy into electrical energy. These cells are kept in a grid-like pattern on the surface of the panels. The panels are usually made of crystalline silicon cells.

The solar energy source is free and renewable. It is one of the most popular renewable resources used in buildings and households for various purposes like lighting, cooking, heating, washing, and operating multiple electrical appliances. In addition, solar helps reduce carbon emissions to the atmosphere. So, it is environmentally friendly.

Solar panel cleaning (Source: Tzahi V from Getty Images Signature on Canva)

Solar panels require low maintenance. Simply, cleaning with water will get the job done most of the time. However, dust and dirt cause the solar panels to work inefficiently. The cleaning process includes removing dirt from the panels' surface to absorb the sunlight properly. In addition, other particles like leaves and bird droppings can also block the solar panels from being exposed to direct sunlight.

The proper way of cleaning solar panels is with water and a sponge. Some also suggest using soap water. But it can leave residues and encourage dirt to stick to them. Often, rain cleans off the dust and dirt. But bird droppings and residues might remain on the surface. So, it is best to use water and soft sponges to avoid scratching the surface.

In this article, we will learn more about cleaning solar panels and their benefits.

When to Clean Solar Panels?

Solar panels are installed in an open environment. Therefore, the solar panels become dirty depending upon the time and space. But the cleaning depends on several factors like your area, weather conditions, exposed time, and solar design. So, it might not necessary to clean them at all during the spring and summer seasons. But, during winters—especially when the sunlight is less available throughout the day—you might need frequent cleaning. Since it rains less in the winter, it is probably reasonable to clean the panels at least once a month.

A dirty and clean solar panel (Source: Tzahi V Canva

You should check the solar panels from time to time. If there is excessive dust, it is time for cleaning. The appropriate time to clean them is early in the morning or in the evening (late afternoon). You can also do it on an overcast day. In the afternoon, the sun falls directly into the panels. So, it can evaporate the water quickly, and the dirt might remain on the surface.

Early morning is a good time because it will form dew on the surface overnight. Further, you will need less water and effort for cleaning. Moreover, in the afternoon, the panels work more efficiently, and you would not want to interfere with it during its most productive time of the day. It might also not be a pleasant experience for you to clean in the hot weather when the sun falls directly during the afternoon.

How to Clean Your Solar Panels?

As we said, the easiest way to clean solar panels is with water and a soft sponge. Some suggest using a mild detergent too. However, do not use water pressure as it can cause damage to the panels' surface. Instead, use the sponge to remove dirt like bird droppings and wash it off with water and detergent.

Technician cleaning solar panels (Source: Arkadiusz Wargula  Canva)

Do not use strong detergents or chemicals. They might also cause damage. Furthermore, always consider safety measures when cleaning. For example, use a long-handled tool to reach the panels while staying on the ground.

Usually, the cleaning requires nothing more than a garden hose. But again, use it at a low water pressure. The hose works in the same way as the rain to clean the surface. If the panels are unreachable from the ground, use a ladder to climb up. You can also use ropes and harnesses if necessary. But, always consider safety measures.

Another way to clean solar panels is to hire a professional cleaning service. Many companies provide this service in exchange for a certain fee. For instance, some companies might charge you annually, while others might charge you for a one-time service.

But, before considering professional cleaning services, you must look into the return on investment of hiring them. If you are spending hundreds of dollars just to get 5 to 10 percent efficiency from the panels, it might not be worth it.

How Often to Clean Your Solar Panels?

Solar panels require low maintenance. You do not have to clean them as often as you might think. Sometimes, particles like bird droppings and leaves can block the panels from receiving sunlight. In such cases, you have to clean them as soon as possible.

An owner cleaning the solar panels (Source: Orietta Gaspari  Canva)

However, solar panels get cleaned on their own. Even though the surface collects dust and dirt throughout the day, they will not be enough to disrupt the working of the panels. A study conducted by the University of California San Diego showed that solar panels left out without cleaning for 145 days lost only about 7.4 percent of efficiency. So, you do not need to clean the panels very often.

In general, you should clean the panels once every spring, summer, and autumn season. However, you should clean it once every month during the winter season because the sunlight is minimum during this time.

But, if unusual events like blockage due to leaves, snow, and bird droppings occur, you must clean them immediately. But, again, several factors like the weather conditions, area, and pollution might impact how often to clean your solar panels.

Some experts also suggest cleaning the panels only once or twice a year. Further, it is also good to observe the panels' energy efficiency changes before and after you have cleaned them. In addition, you must watch how the cleaning time intervals impact the output.

Cost to Clean Your Solar Panels

As said before, you can hire a cleaning service to clean your solar panels. Many companies will provide you with this service. But, before you make the professional cleaning decision, you must look for the cheap option first, which is to clean the panels by yourself. It is not that difficult. You only need water, detergent, and a sponge.

The cleaning companies come with fancy cleaning equipment, tricking you into believing that they will clean it better for you. Therefore, spending money on them might not be worth it if you can do it yourself. However, if you have many solar panels for cleaning, you should consider hiring the companies.

So, if you do not have the time and equipment to clean them by yourself, let these companies handle the cleaning for you. But, again, you must understand that you do not need to clean the panels very often. Having the cleaning companies visit once or twice a year will be enough.

Depending on your area and your solar panels’ size, the cost of cleaning them might differ. Usually, it can cost anywhere from $100 to $600 per visit to hire solar cleaning companies. So, it is your decision; do you want to spend hundreds of dollars cleaning your solar panels? On the other hand, if you can do it yourself with almost zero dollars in cost, why not consider taking the time and effort to do so?

Best Method to Clean Your Solar Panel [Stepwise]

The best solar panel cleaning method uses only water, a soft sponge, and mild soap (or detergent). Consider doing the cleaning by yourself as hiring professional cleaners might not be worth the money.

Cleaning solar panels is quick and easy. If you plan to do it yourself, always consider the safety measures because you might have to climb on the roof. Below is a stepwise process of the basic cleaning process.

• Step 1: Check your solar panel manufacturer if they have any specific recommendations for cleaning the panels.
• Step 2: Consider cleaning in the morning or late afternoon. You can also do it on a cool day.
• Step 3: Clean gently with a garden hose at first. Usually, if there is not much dust and dirt, that will do it. However, if the panels are still dirty and contain bird droppings and other particles, you need more cleaning.
• Step 4: Take a bucket with clean water and mild soap. Use soap water to clean the surface of the panels gently. However, make sure that you don’t leave any residue. You do not have to clean the wiring underneath the panels.
• Step 5: Rinse the panels with clean water with the hose and use a squeegee to dry off the panels. But you can also leave them to dry naturally.
• Step 6: Repeat the process until all panels are clean.

As we said, always consider safety measures if you have to climb up on the roof. Use a ladder, rope, and safety harness if you must climb up. Further, if the places are unreachable with your effort, hire a professional cleaning service. They will have all the equipment and experienced cleaners who can climb and do all the work for you.

Is Solar Panel Cleaning Worth it?

Most experts say that it is not worth it to clean your solar panels by hiring cleaning services. The return on such investment doesn’t justify it.

The average change in the efficiency of solar panels when they are dirty is 5 percent. But, in most climates, the next rain will wash off the dirt and allow the panels to return to their maximum output. So, just because there is some dirt on your panels, you do not have to clean them immediately unless it has extensively affected the efficiency.

Furthermore, solar panels are installed in a tilted form. So, most of the time, the bottom of the panels will collect dirt or water runoff. But this will not decrease the output of the panels. Even if it does, it will be very little. So, it is not something you should be worried about.

Cleaning solar panels can require a lot of effort. It is not easy to climb up on the roof and clean them yourself. It might not be worth it because that amount of effort will only provide a little outcome. However, solar panel cleaning is worth it only if the efficiency has been affected due to the dirt collected on the surface. Especially in the winter seasons, the panels can get dirty when it does not rain for months. During such times, it will be worth it to clean them and regain the panels' performance. Furthermore, cleaning solar panels can increase the system performance and, as a result, reduce your electric bills.

Tips for Maintenance and Cleanliness

A solar panel-based energy system is not only about the panels. It also includes other components like a battery, inverter, and solar charge controller. So, it is not that if you clean your panels regularly, your system will work fine. The performance of harnessing solar power depends on the maintenance of all the components of the system.

A solar panel system requires low maintenance, and solar panels can last for decades. But they will not last forever. Every electronic piece of equipment wears off over time. However, with regular maintenance of the panels and the overall system, you can increase the number of years it lasts and provides good performance.

Cleaning solar panels is only a part of its maintenance. So do not just focus on the cleanliness of the panels. Also, check the overall system and whether all the components are working together to provide maximum efficiency. In addition, you can also hire local electricians or solar technicians to check your system for its maintenance.

Conclusion

A solar-based system for heating, lighting, cooking, washing and other purposes has become popular among most households. Solar is one of the most commonly used renewable energy sources today. Check frequently if the system is working correctly. See if your panels have a lot of dirt on the surface. If there is only a little dirt, you should not be worried. But if these panels are very dirty, then cleaning is necessary to increase the system's energy efficiency.

Solar panels get dirty over time. Dust, bird droppings, leaves, and other particles get caught up on the surface. A lot of dirt reduces the energy efficiency of the panels. Hence, cleaning them would be appropriate. In general, solar panels require low maintenance. Therefore, cleaning them is easy as you only need water, mild detergent soap, and a soft sponge.

Another way to clean your solar panels is to hire professional cleaning services. They will charge specific fees for their service. However, most experts say that it is not worth it to hire cleaners for your solar panels. Plus, you do not need frequent cleaning. Once every season will do it. So, think before deciding to hire anyone to clean your solar panels.

Frequently Asked Questions (FAQs)

1. Why should you clean your solar panels?

The presence of dust, dirt, bird droppings, leaves, and other particles negatively affects solar panels' efficiency. Therefore, you must clean the panels. According to the study conducted by Google, solar panel cleaning is the best way to increase their energy efficiency. Further, the experiment also concluded that rain alone is not enough to clean the solar panels.

So, it is good to rely on rain for natural cleaning. But as time passes and your panels get older, you must clean them at least once or twice a year.

2. What do I use to clean solar panels?

The best way to clean the solar panels is by using water, mild soap, and a soft sponge. Also, you can use a garden hose to spread water on the panels' surface. Further, you must be very careful not to scratch the panels in any way. Do not use high-pressure water on the surface as it will damage the panels. Instead, use mild soapy water and wash the panels with a soft sponge. Then, rinse it with clean water with the help of the hose.

3. Will neglecting solar panel cleaning cost me money?

Probably, yes. Solar panels lose their energy efficiency if you do not keep them clean. Even though they require low maintenance, they can still lose 15 to 25 percent efficiency if you do not clean them for very long.

It means that your solar-based electric system will produce 15 to 25 percent less energy. The primary purpose of installing the system is to reduce the electricity bills. Also, the installation can cost you a lot of money. So, keeping the solar panel clean means that you are utilizing your investment to its full potential. You will be adding a couple more years to the payback time.