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Understanding the Differences Between Window Cleaning and Solar Panel Cleaning: A Health and Safety Perspective

Written By: Steve Williams, Founder, International Solar Cleaning Academy

The International Solar Cleaning Academy (ISCA) is dedicated to promoting best practices in the cleaning and maintenance of solar panels. One common misconception we encounter is the idea that solar panel cleaning is just like window cleaning. While both tasks involve cleaning glass surfaces, there are significant differences, particularly when it comes to health and safety.

Material Differences

Window Glass:

Solar Panel Glass:

  • Solar panels are composed of tempered glass that protects delicate photovoltaic cells. This glass is often coated with an anti-reflective coating (ARC) to maximize sunlight absorption.
  • Cleaning solutions and methods must be compatible with these coatings to avoid damage and in order to maintain the warranty of the solar panels. Using chemicals not approved by solar panel manufacturers can invalidate your client’s warranty.

Functional Differences: Purpose and Sensitivity


  • The primary purpose of windows is to provide light and visibility. Cleaning windows mainly improves aesthetic appeal and visibility.

Solar Panels:

  • Solar panels are designed to convert sunlight into electricity. Dirt, dust, and debris can significantly reduce their output and overall efficiency. Many studies have been done by institutes such as the National Renewable Energy Laboratory (NREL) to prove drops in output from a lack of solar panel cleaning.
  • Panels are sensitive to scratches, abrasive materials, and certain chemicals that can damage their surfaces, reduce their efficiency, or worst-case damage the panel’s functionality.

Health and Safety Considerations

Risks Involved

Window Cleaning:

  • Risks include falls from heights, especially when cleaning high-rise buildings.
  • Exposure to harsh chemicals that can cause skin and eye irritation.
  • Improper ladder or scaffolding use can lead to accidents.

Solar Panel Cleaning:

  • In addition to the risks associated with window cleaning, solar panel cleaning involves the added danger of working near electrical systems.
  • Electrocution is a significant risk if proper precautions are not taken.
  • Solar panels are often installed on roofs or in elevated positions, increasing the risk of falls and the likelihood of coming near or in contact with overhead power lines.
  • Solar panel cleaning robots are a rising cleaning technique. Handling the robots has an increased risk of musculoskeletal injuries if proper ergonomics are not followed.  Robots vary in weight from 45kg to 115kg (100-250 lbs.). Some are one-man lifts and some are two-man lifts. Care must be taken when handling solar panel cleaning robots.

Safety Measures

Window Cleaning:

  • Ensuring ladders and scaffolding are secure and used correctly.
  • Using environmentally friendly and safe cleaning solutions to minimize chemical exposure.
  • Cleaning high windows with waterfed or telescopic poles to keep your feet on the ground.

Solar Panel Cleaning:

  • Comprehensive solar panel cleaning training with a focus on solar panel electrical safety to avoid electrocution, such as that provided by ISCA.  This training is available in 33 countries and 26 languages.
  • Use of the correct PPE. There is a common misconception that any rubber glove will provide sufficient protection when solar panel cleaning. This is not true. Use of the correct rating of PPE is imperative. Ratings of PPE to protect from electrocution varies from country to country and according to the size of the solar array being cleaned. Correct country-specific training will ensure you know what rating of PPE you need for your area and array type.
  • Use of insulated tools and equipment to prevent electrical contact.
  • Strict adherence to local country health and safety regulations and guidelines for working at heights, including the use of harnesses and fall arrest systems.
  • Regular inspection and maintenance of cleaning equipment to ensure it is in good working condition.
  • Use of non-abrasive, solar-specific cleaning solutions to avoid damaging the panels. Any chemical used must have written approval from the solar panel manufacturers prior to use.

Techniques and Equipment                         

solar cleaning panel technique

Cleaning Techniques

Window Cleaning:

  • Typically involves techniques such as spraying with a cleaning solution, using a pure water system, and wiping with a cloth or squeegee.
  • Pure water cleaning is optional but recommended for the best clean for regular window cleaning. This method might include extension poles or waterfed pole systems for higher windows.

Solar Panel Cleaning:

  • Requires specialized techniques to avoid scratching or damaging the panels. This often includes using soft-bristle brushes on water-fed poles, rotating brushes or solar panel cleaning robots.
  • Pure Water cleaning is required for solar panels to prevent mineral deposits from forming on the glass.
  • Tractor-mounted cleaners are often used for large installations to ensure consistency and safety.

Equipment Used

Window Cleaning:

  • Common tools include glass squeegees, scrapers, and extension poles.
  • For high-rise buildings, window cleaners may use harnesses, scaffolding, or lift systems. For safer high-rise window cleaning, telescopic waterfed poles with a pure water system are the typical route, keeping the cleaner’s feet securely on the ground.

Solar Cleaning:

  • Specialized equipment such as waterfed poles with soft-bristle brushes, robotic cleaners, and deionized water systems are used.
  • Personal protective equipment is crucial, including insulated gloves, safety harnesses, and the correct rating of non-conductive boots. Again, country-specific safety training for solar cleaning should discuss this topic in detail.
  • Advanced monitoring tools like drones with thermal imaging can be used to assess the cleanliness and condition of solar panels.

Environmental Impact: Cleaning Agents


  • Often standard glass cleaners are used, which may contain chemicals harmful to the environment.
  • Pure water technology produces deionized water and when used in cleaning with waterfed poles, it does not leave any harmful residue or chemical runoff.

Solar Panels:

  • Solar cleaning often uses eco-friendly, biodegradable cleaning agents to protect the environment and the panels themselves.
  • Just as with window cleaning, deionized water is often used to remove the impurities that cause mineral deposits.

Stay Safe and Keep Your Solar Panels Shining

While window cleaning and solar panel cleaning might seem similar at first glance, they are fundamentally different tasks and different industries. They require unique approaches, especially concerning health and safety. Solar panel cleaning demands specialized knowledge, equipment, and safety measures to ensure both the efficiency of the panels and the safety of the cleaners.

The International Solar Cleaning Academy emphasizes the importance of proper training and adherence to safety protocols to prevent accidents and ensure high-quality maintenance of solar panels. Understanding these differences and implementing the appropriate safety measures is crucial for anyone involved in solar panel cleaning.

For more information on solar panel cleaning training programs and resources, visit the ISCA website or contact ISCA

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