FREE ebook! All You Need to Know about Residential Solar Panels-Buyer’s Guide

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How To Clean Solar Panels Properly

By
02/04/2020 6:50 PM

Do you have solar panels installed on your roof? Need to clean them? This guide covers how to clean solar panels on your roof. We will also see how to clean solar panels on garden lights.

Thinking about it – do you clean your roof often? Maybe you should.

A lot of people think it’s ok to not clean the roof often thinking that rain is enough to keep it clean. Surprisingly a lot of people think this is also the case for solar panels – that rain will keep them clean. Actually, rain does do a pretty good job at cleaning solar light panels as pollen dust and other dirt get washed off each time it rains.
Also, most residential solar panels are tilted at a high angle so that most dirt actually rolls off the roof rather than sticking in place but there is often some build up on the lowest panel.
It is a good idea to clean your solar panels from time to time however, for example, you may get birds mess that rain won’t clean off easily.
If you live in a climate that has drought conditions on a regular basis then you are not going to get enough rain to keep your solar panels clean and the rain that you do get may be light and misty.

Do debris and accumulated dirt on your solar panels actually reduce the solar panel efficiency?

Too much debris and dirt can reduce the amount of sunlight that gets through to the converter which changes the light to energy. This loss of efficiency is not substantial – often less than 5%.

The most common solar panels on residential households is around 5-kilowatt hours of electricity generation so a reduction of 5% equates to a loss of $20 that you would save on your energy bills for the year so it often doesn’t add up financially to get a professional in to clean your solar panel.

Some of the solar panel companies from Florida provide annual maintenance service as part of the package when you signed up to get your solar panels installed so you should definitely take them up on that offer. If they want you to pay out of pocket, we recommend not doing that as this is likely to be more expensive than the savings you would get on your energy bill.

Dirty Solar Panel

So if you decide that you want to have your solar panels cleaned it’s usually a good idea for you to do it yourself but bear in mind you are going to have to get on your roof with a hose and a bucket.
If you decide to clean your solar panels yourself you will find it very easy – all you need to soap and a hose, you don’t need any particular solvents or specialized equipment.

Let’s say you want to clean the solar panels on your roof yourself, first up you need to check to see if the solar panels actually need cleaning, this is especially true if you live in an area that gets a good deal of rain from time to time.

Related article: Sustainable Building Methods

What you need to do is physically inspect the panels for telltale signs of dirt, bird mess, debris and so on. Some solar panels have systems that monitor performance and will send you text alerts if they are not working as they should so you may not even need to do the manual inspection. These alerts cover electrical performance, mechanical defects, and cleanliness.

Cleaning solar panels is a lot like cleaning a car

You don’t want to get scratches on your solar panel in much the same way you don’t want to get scratches on your car so just take a bucket of soap water up onto your roof and use a hose. Apply the soap water using a non-abrasive cloth or sponge. Make sure you use a hose on a gentle pressure setting, using a high-pressure sprayer will damage the mechanical workings of the solar panels on your roof.

If using water is not working

For example removing birds' mess then you can use a little washing liquid that you use for your dishes but nothing stronger like laundry detergents and industrial-strength solvents.
In terms of environmental health make sure you wait until a cool day, preferably with clouds in the sky to protect yourself from getting sunburned and also from damaging yourself on the solar panels as these tend to run very hot on sunny days.
If you notice fluctuations on your electricity bills or you get an alert from your solar panel system it may be worth cleaning your solar panels yourself but other than that it is not to be recommended.

How much does it cost to clean solar panels?

Cleaning Solar Panels Cost

If you clean the solar panels yourself it’s just your time cost, set aside an hour, get a bucket of soapy water and a hose.
Professional solar panel cleaning can cost a lot.
In the United States, the average cost to have residential solar panels professionally cleaned is around $130. This is compared to the average energy bill savings you will get of $20. Those professional quotes depend on a number of factors including labor laws, the number of panels you have, how accessible it is to access your solar panels such as how many stories you have and the height of your roof and, as always, your zip code.

FREE ebook! All You Need to Know about Residential Solar Panels-Buyer’s Guide

We review the most important companies in the USA, here are a few of them:

The solar panel industry says that your solar panels should be cleaned twice a year in order to maintain the peak power output of the solar panels. Professional cleaning companies usually charge a flat rate or a variable rate depending on how many panels you have.
Flat rate panel cleaning usually costs around $150 for 32 panels. Variable per-panel costs usually run from $8 - $10 per panel depending on panel size, location, and accessibility.
If you decide to hire a professional cleaning company it is usually recommended to hire a company that actually specializes in solar panels. Always check reviews before hiring a contractor. Only hire contractors that have liability insurance, ask them before arranging bookings.

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Another factor you should consider is that if you chose to clean the solar panels yourself with a bucket of soapy water and a hose is that you could damage your solar panels if you use the wrong cleaning fluids or scratchy dishcloths.
If you live in a hard water area, it’s a good idea to leave it to professionals. The same is also advised if your roof is high and if you don’t have the right equipment such as a hose.

If you go about cleaning your solar panels yourself there are a few things you need to keep in mind, first, safely access your roof – climbing onto the roof with a bucket of soap water is not recommended. Ask your solar panel manufacturer for instructions on how to clean the solar panels. Find out if your water will not damage the solar panels, for example, if you live in a hard water area. Use an extension brush that is fine bristled and warm soap water. Pressure washers will damage solar panels. Finally, do not clean panels at hot times of the day as residue from the soap will damage the solar panels.
Using water with high mineral counts leaves stains and water spots on solar panels which damages them.
Some professional cleaners bring water deionizers on-site to make the water softer.

How to clean solar panels from the ground

Clean Solar Panels From The Ground

For safety, you should try to clean solar panels from the ground using a squeegee on top of a plastic blade in addition to a sponge covered by a cloth. Both the squeegee on one side and cloth-covered sponge on the other should be attached to an extension pole so that you can clean the solar panel from the ground.

How to clean solar panels on garden lights

Solar Panel Outdoor Lights Cleaning

IF the solar panels on garden lights get an accumulation of debris and dust they may not charge fully during the hours you get sunlight. This means that the garden lights may not stay on for the full duration of their battery as the battery in the garden lights will not be fully charged. Accumulations of dirt and dust may also reduce the battery life of garden lights so it is important to clean them.

To clean solar panels on outdoor lights you use soapy water and a sponge. If there is a lot of mud on the garden lights you should also use a brush with soft bristles to get rid of debris that won’t get taken out by using a sponge only.
It’s a good idea to clean the solar panels on garden lights about once a month.

How to clean snow off of solar panels

Solar Panels with snow on them

There are a number of ways you can clean snow off solar panels.
First off you could just wait for the snow to fall off. No, I’m serious – this might be a good option if your solar panel is pitched at a bank angle of 35 degrees – the snow melts and falls off of its own accord.
The second option is to sweep the snow off, this can be dangerous though. Be careful if you decide to use a roof rake or something similar attached to a squeegee so you don’t damage your solar panel.
Number 3 is to hose it with a hosepipe. You need to be careful because if the water is too cold the snow could solidify into the ice instead of falling off the solar panels on the roof.
Another way is to use a leaf blower connected to an air hose or pipes made from plastic or PVC to create warm air and blow it onto the snow, melting the snow so it falls off much in the same manner as rainwater also falls off your solar panels. Finally, just throw something at it like a football – this is surprisingly effective for light snowball and does the trick.

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One final thing to bear in mind never use car wax or rock salt on your snow-covered solar panels as this will damage the roof shingles. If you use hot water instead of cold you could fracture your solar panels.

Concluding remarks

  1. You may not need to clean your solar panel as rainwater often removes most pollen dust and other dirt from the panels.
  2. Solar panel manufacturers recommend you clean your solar panels every 6 months and sometimes this is included in the installation package you agreed with the solar panel fitter but other times it is an out of the pocket expense.
  3. Getting a professional solar panel cleaner can cost upwards of $10 per panel up to around $130 for a fixed fee package. You only save around $20 a year on energy bills from having your solar panel cleaned professionally.
  4. Most solar panels have alert features to warn you when you need to clean your solar panel so you don’t need to concern yourself too much about cleaning your solar panels.
    As a rule, it is more cost-effective to clean solar panels yourself using soap water and a squeegee connected to a plastic or PVC extension pole.
  5. Cleaning solar panels is a lot like cleaning a car – you don’t want to get scratches.
  6. Clean solar panels on a cool day to avoid damaging your solar panels as they will be too hot to clean and also you risk injuring yourself.
    If you live in a hard water area, it’s a good idea to leave it to professionals.
  7. To clean solar panels on outdoor lights, use soapy water and a sponge.
  8. Snow can be cleaned off solar panels by waiting for it to fall off, sweep snow using a roof rack or similar pole attached to a squeegee, hose with a hosepipe, use a leaf blower attached to an air hose or simply by throwing a football at it.
FREE ebook! All You Need to Know about Residential Solar Panels-Buyer’s Guide
Eduard Munteanu

We are true environmentalists at heart, with a realization that Earth is our only planet, and a wish to enlighten humanity about how to protect our home.