While the rain will wash away some of the dust, pollen, and dirt from your solar panels, it won’t be as effective as a manual clean.
Giving your solar panels a good clean on a regular basis can help to maximize their efficiency and save on your electricity bills. But how do you clean solar panels?
This article discusses the best methods to clean the solar panels mounted on your rooftop.
Safety First
First and foremost, do not attempt to work on a dangerous roof. If your rooftop is steeply sloped, then consider calling a professional to clean the solar panels. They’ll have the right equipment and years of experience. Flatter roofs with only a slight slope will be much safer for you to tackle.
Choose the Right Ladder
You’ll most likely need a frame or an extension ladder. If you’re using an extension ladder, extend it three feet above the gutter and use the ladder’s stabilizer.
Cleaning Supplies
Here are the things you’ll need to clean your solar panels:
- A regular garden hose with a spray nozzle
- A soft bristle broom
- A plastic scraper
- Extension poles
- Gloves
- A bucket
- Tap water. However, if your water contains lots of minerals, you may want to use purified or distilled water instead to prevent mineral build-up on the glass.
- Mild liquid soap that doesn’t contain chemicals that could damage the panels. Strong chemicals may negatively interact with your solar panels, so it’s best to keep the cleaning agent you use simple. Plain water would be perfect.
Best Time to Clean Them
The best cleaning time would be either in the morning before the sun has heated the panels, or in the evening once they have cooled down. Note that applying cold water to your solar panels when they’re hot can potentially crack the glass.
Cleaning Technique
Before you begin, check with your solar panel manufacturer or installer to verify the information regarding cleaning your panels. For example, the dos and don’ts, or recommendations when cleaning your specific system.
Next, we’ll discuss two cleaning techniques. One for when your solar panels are not particularly dirty and another for when they’re extremely dirty.
Minimal Dirt Build-Up
If your panels are covered with dirt and dust build-up, then you likely won’t need to do more than give them a quick hose-down. Once you’ve finished doing so, you can leave them to dry off in the sun.
Be sure not to use a high-pressure jet spray or a pressure washer, as the pressure could damage the panels leading to less efficiency and performance.
Extensive Dirt Build-Up
If the dirt on your panels is more than just dust, or pollen, etc., and includes various sticky matter like bird droppings, then a good scrub is required. Use some of the cleaning supplies discussed earlier – without being too hard on the panels.
Here’s how to clean them:
- Fill your bucket with warm water then add a little mild liquid soap.
- Use the spray nozzle on your hose to spray the panels. Rinse off as much of the dirt as possible and loosen the stubborn sticky matter.
- With the soapy water, use your soft-bristled brush to gently scrub each panel. Use your extension pole to extend the length of your brush if necessary.
- Clean the bottom edge of the panels where all the dirt accumulates using a horizontal motion.
- If required, to remove even more dirt, use your scraper and gently scrape the surfaces. Be extra careful on the areas with heavy residue.
- Thoroughly rinse the solar panels to remove any remaining residues and soapy water.
- Now let the panels dry off naturally in the sun.
Solar Panel Cleaning Kits
Alternatively, you could buy yourself a solar panel cleaning kit. These handy kits include biodegradable soap, a small brush or one with a long handle, and a wiper. To clean your panels, do the following:
- Mix the soap with water in a bucket. Advice on how much soap to use will be somewhere on the label.
- Dip the brush in the soap water then gently wipe your panels.
Benefits of Keeping Your Solar Panels Clean
Dust, pollen, dirt, bird droppings, and other debris can negatively affect the efficiency of your solar panels. Google’s innovative experiment conducted at their 1.6-megawatt solar farm found that cleaning solar panels was the best way to maximize the energy produced. When cleaning solar panels that had been in operation for 15 months, their electricity output doubled. They concluded that relying on rain alone is not an adequate way of keeping them clean.
Neglecting Them Could Cost You Money
It’s a reasonable assumption that solar panels can lose between 15%-25% efficiency if they’re not cleaned occasionally. In other words, they will generate 15%-25% less electricity. You’ll need to make up for this loss by sourcing electricity from a utility company at their price.
Enemy Number One: Bird Droppings
Bird droppings on panels are much more damaging than dust or other debris.
Does your system include micro-inverters or a string inverter? This is key. Solar panels with micro-inverters can indicate which section is covered in droppings. During this time, the inverter will stop showing current flow.
If there are a lot of trees close by, especially of the deciduous variety, not only will the leaves fall on your panels, but birds will be attracted by the leaves. Over time, both will create build-up and debris which makes it even more important to clean the panels regularly.
Another thing to consider is the angle of the panels. Flat panels require the most upkeep since standing water can turn into puddles and leave a muddy residue after it evaporates. Angled panels allow the rain to run down, which helps to keep them clean.
Maintenance and Upkeep
Generally, when your solar panels are angled, the rain will help keep them clean. However, monitor how your solar panels are functioning by paying close attention to your energy bills and monthly usage.
If you notice an increase, you can use this to gauge when it might be time to clean your panels or perform some other form of maintenance. After cleaning them, check whether the panels’ efficiency returns to normal. However, if the fluctuations to your bills continue there could be an electrical fault.
Another way to tell how well your solar panels are functioning and performing is by monitoring system alerts. They’re useful for knowing whether there is a problem with your panel’s cleanliness or if there is an electrical or mechanical fault.
How to Clean Your Solar Panels – Recap
Clean solar panels are fundamental to their efficiency. Many people believe that manually cleaning your panels is not necessary as the rain should suffice. However, it has been found that rain alone isn’t enough.
For panels with dirt build-up, a rinse off using your hose should do the trick. When there is significant build-up, use a soft brush and soapy water, then rinse off using the hose. Aim to clean them before the sun has come out or once it’s gone down.
To know whether it’s time to clean your panels in the first place, carry out an eye test to gauge the level of dirtiness. Other ways that confirm its maintenance time are unusual fluctuations in your electricity bill, or if you’re receiving maintenance alerts from the monitoring system.
Keep Things Simple
So, how do you clean solar panels? Keep things simple. Once you’ve decided on a safe way to get onto your roof, all you’ll need is a bucket of mild soapy water, a soft brush, and a spray nuzzled water hose.
Hopefully, our article has given you all the advice your need to keep your solar panels clean and functioning properly.