How Often Should I Clean My Solar Panels?

You finally took the plunge and bought solar panels for your house. Then you start to notice the efficiency drop and you realize that they are in need of a good cleaning. Now you’re wondering how often you should clean your solar panels.

So how often should you clean your solar panels? The short answer to this question is that, at a minimum, solar panels should be cleaned about every six months, or twice per year.  Cleaning the panels twice a year not only gives owners the chance to remove built up residue and grime, but it also gives owners the opportunity to inspect the solar panels up close in order to handle any necessary maintenance or repairs.  Of course, various factors can influence how often and when you perform routine cleaning on your solar panel system.

Depending on where you live, local weather, and other influences, you may have to clean your solar panel twice as much as someone in another state. We combing through the data to put together a detailed guide on how often you should clean your solar panels.

Why Is It Necessary To Clean My Solar Panels?

Solar panels are a wonderful energy option allowing us to harness solar energy in a way that translates the power of the sun into real, useable energy and power that can be used throughout your home.  Although solar panels are rather self sufficient, they do require a moderate amount of routine cleaning in order to keep the solar panels working as efficiently as possible.

A solar panel works by allowing the sun’s rays to gather on the surface, transforming the photons into useable energy.  Much of the mechanisms required to transform the photons relies on having a clear path into the photovoltaic system.  Pollutants, such as dust, leaves, grime, and bird droppings can land on the glass of your solar panels. This creates areas where the sun’s light cannot effectively penetrate the system. 

Without proper removal, the light is not able to enter the system as optimally as possible. That reduces the overall efficiency of the system.  While rainwater can certainly help remove some of the pollutants and grime, research has found that rain water alone cannot keep your panels clean enough to generate the maximum amount of power over a lifetime of solar production. 

How Often Should I Clean My Solar Panels?

 The Earth’s resources are being consumed at an alarmingly fast rate causing populations to look toward sustainable and renewable energy options.  As resources become consumed, energy prices escalate creating a constant loop of not enough supply met with too much demand.

Smart consumers are starting to turn to renewable energy choices, such as solar power. They are trying to build a sustainable and cost effective energy option.  Although solar panels are relatively maintenance free, they do require regular cleanings in order to operate as efficiently as possible. This helps provide a lifetime of sustainable and renewable energy.

Factors Influencing Solar Panel Cleaning Schedule

Scheduling your solar panel cleaning depends on a couple of different factors. The four main factors that can influence your solar cleaning schedule are:

  • Location – The location of your home or business will drastically impact the amount of cleaning necessary for your solar panels.  Different parts of the world are subject to a higher level of pollen and dust circulating in the atmosphere.  Heavy pollen loads can build up on your solar panels, making them less efficient.  Further, heavy leaf production or bird droppings can also impact the performance of your solar panels.  If you live in a wooded area, or an area frequented by avian visitors, it may be necessary to clean your solar panels more often. 
  • Tilt – Solar panel arrays that are positioned on the roof are often set at a tilt that is at least a 5% slope.  This tilt is designed to help snow and water run off the panels.  Often, solar panels with a lower tilt will require more regular cleaning.  When it rains, dirt and debris is washed away, but can remain pooled at the bottom of the panel.  When the pool of water dries, the debris is left as a film at the bottom of the panel. This debris must be removed.  Solar panels with a steeper tilt do a better job at draining away pooling water, and often will need cleaned less frequently. 
  • Weather – Areas that are subject to more frequent rain and snow will often need the solar panels cleaned less often.  This is because the rain works as a natural cleaning agent, removing some of the collected dust and pollen.  If you live in a drought prone area, you may require more frequent solar panel cleanings.  Areas that experience a high amount of wind may also need more frequent cleanings.  High wind can cause pollen and dust to collect on your panels at a faster rate. This may require you to clean the panels more often. 
  • Energy Usage – One of the best tell-tale signs that your solar panels must be cleaned is the amount of energy your panels are producing.  It is best to regularly monitor your solar panel energy production over time.  If you notice that your production is starting to decline it may mean that a cleaning is in order.  Keep a close eye on your energy production trends which may shed light on your cleaning schedule. 

For most areas, it is best to clean the solar panels at the start of spring. Then again at the start of fall.  Following a long winter, spring is the ideal time to remove any built up dirt and debris. It may have collected on the panels with accumulated snow.  As you head into the fall and winter, a regular cleaning is a wonderful way to remove built up pollen and dust that collected during the warmer summer months. 

What Should I Use To Clean My Solar Panels?

Cleaning your solar panels is really quite simple.  The best way to clean your panels is with purified water and a soft bristled brush.  Simply spray the panels and use the brush to scrub or wipe away any film, residue, and debris that may have collected on your panels in between cleanings. 

Simple water and some good old-fashioned elbow grease should be enough to get your solar panels looking, and performing their best.

What To Avoid When Cleaning Solar Panels

Never use a power washer to clean solar panels.  Even though many power washers can scale down and regulate the amount of pressure used, too much pressure can damage the solar panels and cause cracks and chips to form in the glass.  When cleaning the solar panels, simple purified water is enough to wash away any dirt. 

Using harsh and caustic chemicals run the risk of scratching or damaging the glass which could impact the performance of the solar panel.  Also, remember to avoid putting direct pressure on the solar panels as you move about the space to perform routine cleaning.  Never directly step on the solar panel or apply direct pressure which could damage the panel. 

Safety First When Cleaning Solar Panels

When cleaning solar panels be sure to consider your own safety first and foremost.  Solar panels have a tendency to get extremely hot. This can cause you to burn yourself if you attempt to clean them at the wrong time of the day.  It is best to clean your solar panels in the early morning before the sun has a chance to heat up the panels. Or clean them in the early evening as the panels have a chance to cool down from the sun’s exposure.

Further, if your panels are located on the roof it may be best to hire a professional service.  Roofs can have a steep pitch and can be high off the ground.  If you are not experienced navigating a roof, there is a high fall potential which could cause serious injury.  If you are in doubt, call a professional service to help handle your solar panel cleaning. 

Lastly, before starting to clean your solar panels, you will want to check with your solar panel manufacturer.  Many companies will have specific cleaning requirements that will help to optimize both the performance and lifespan of your solar panel array.  Following the instructions by your manufacturer will optimize your solar panel performance. It will also help maintain a warranty on the product as well. 

What Are the Benefits of Cleaning My Solar Panels?

Performing routine cleaning on your solar panels has several benefits.  Not only are you able to keep your solar panels looking great, but you will be able to boost performance and increase their longevity with twice per year cleanings. 

Solar Panel Routine Maintenance

By cleaning your solar panels at least twice per year, you have the opportunity to perform routine maintenance.  Getting up close to your solar panels to scrub away dirt and debris allows you to inspect your solar panels.  This allows you to examine the panels for any cracks or chips that may start to form in the glass that makes up your panels.

Further, any rust or damage to the wires connecting your panels can be detected and repaired early.  Try to find small potential problems, before they escalate into larger problems. Then you can minimize the risk of potential fire or damage to your solar panel. 

Better Performance For Solar Panels

Experts in the solar industry had long believed that simply allowing the natural rain to wash away grime and dust was enough to keep your solar panels working optimally.  A recent study performed by the World Renewable Energy Congress based in Sweden proved that wrong. The study found that simple rainwater is not enough to keep your solar panels working as best they can.

The study found that allowing dirt, grime, and debris to build up on the solar panel directly impacted the solar panel’s ability to produce useable energy.  In fact, up to 7% efficiency was lost every month that passed without regular cleanings.  This energy loss was compounded over the course of years which accounted for over 25% in energy loss.  Similarly, Google conducted their own experiment on their solar array located in Mountain View, CA. 

When examining the power output from the solar panels the team of scientists discovered that the number one cause of power distribution decrease was a dirty panel.  Cleaning the panels saw an instant and dramatic result, increasing the power output by 36%. Google was able to conclude that the number one way to increase the overall production and efficiency of solar panels was to perform routine and regular cleaning.  

Save Money By Cleaning Your Solar Panels

Several solar panel owners often turn to alternative energy sources because of the ability to move away from traditional power sources. This helps them save money each month on costly utility bills.  The amount of money you are able to save is directly proportional to the amount of energy you are able to generate. 

When your solar panel is performing under standard specifications, you are potentially missing out on much needed energy production.  By having a clean solar panel, you are able to capture more reusable solar energy. This means converting more energy to useable power. Thus, you will save more money on monthly utility bills. 

Cleaning Solar Panels Extends The Life Of Panels

The overall lifespan of any piece of equipment can be directly related to how well you care for your equipment.  Regular maintenance and routine cleaning can help keep your solar panels in great shape. This sets them up for a lifetime of optimal performance.  Routine cleaning can remove harmful residue that can cause your panels to degrade and break down over time. 

Plus, regularly inspecting your panels while cleaning them can help you identify potential small problems. You have to do this before they turn into larger, catastrophic problems.  Not only can cleaning your solar panels help to improve the overall performance of your solar system, but it can help your solar panels last longer. 

Emerging Technology For Solar Panel Maintenance

Luckily, as research emerges and scientists discover the best way to care for solar panels to optimize their performance products and technology continue to evolve.  There are now several products emerging to help facilitate a cleaner and better performing solar panel. 

Solar Panel Protective Glass Coating

One new product that continues to evolve is a special glass coating designed for solar panels.  This coating goes directly onto the glass and can help eliminate the amount of dust and debris that sticks to the glass.  When the glass is free of debris the solar panel is able to function more optimally.  Plus, a glass that stays cleaner for a longer period of time can lessen the amount of solar panel cleanings required throughout the year. 

Robotic Solar Panel Cleaner

Other technologies include a robotic cleaner that works autonomously to clean the panels.  This is a great option for people who have panels high up on the roof. That might otherwise be too dangerous to clean.  The cleaning robot works at night in order to keep your panels working throughout the day.  Using only water the robot safely scrubs the panels with soft brushes to remove any built up pollen, dust, or debris that has collected during the daylight hours.  

Commercial Solar Panel Residue Monitor

The last piece of promising technology to emerge was created by Kipp & Zonen.  It is a commercial monitor that helps to examine and track the amount of dirt and residue built up on the solar panel.  This tool uses an LED and sensor to monitor the amount of build up. It will then alert the owner when it is time to clean the panels.  Further, the monitor is able to track the output performance of the solar panelsBetter understanding how your solar panels perform can help dictate a cleaning schedule. It will help to remove debris build up, increasing the efficiency and power output of your solar panels. 

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I'm trying to make the world a bit greener every day, whether that's through my day job or helping others make green choices for their homes.

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