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Most Perth systems need cleaning far less often than owners expect, and a fair number never need it at all. Rain does most of the work, and the tilt of a typical array does the rest. Still, a few exceptions can be related to high-performance maintenance, depending on your specific environment. Here’s how to master your local environment’s best practice solar panel cleaning procedure to ensure the best system performance.
The beauty of photovoltaic/solar electric energy is that it is considered low maintenance compared to most other energy generation formats, thanks to innovation away from moving components. Solar cells are energy collectors as they harness photons (light molecules) delivered from the sun. A photovoltaic ‘solar panel’ is an electrical circuit protected from imposing environmental elements through its encapsulation, which is the area of maintenance we consider for solar panel cleaning.
Panel surfaces and soiling
Encapsulation consists of two differentiators, front and rear: a glass or plastic front surface and a glass or laminate rear surface. No matter the composite, the front and back surface acts as a barrier, sandwiching and protecting the delicate electrical circuit. As photons (light molecules) rain down on the front surface, the photovoltaic effect awakens within the solar panel. Therefore, a reduced power output is expected if anything should restrict light from reaching the solar cell on the protective surface.
If PSW supplied your system, our product qualification has already ruled out the coatings and frame designs that make cleaning a recurring job, so your panels, no matter the brand, comply with IEC testing requirements for self-preservation with reduced format interference. Essentially, your PSW-supplied solar panels are considered self-cleaning by ‘rain’ due to a protective layer applied to the glass front surface from the manufacturer.
However, there are instances where manual cleaning from soiling may be required for optimum solar energy system performance.
Cleaning by soiling level
Light soiling (shallow dust layer): Light water stream/spray only, no chemicals, and avoid roof access for safety. Consider a professional cleaning service where personal safety can be compromised.
Frequency1: Self-cleaning by rain. If drought, bimonthly by hose.
Medium soiling (Marks/stains/soiling not removable by water): Spot clean with a non-abrasive cloth and no downward pressure on the solar panel to avoid the potential of spot-induced solar cell fracturing. Manufacturers identify area-induced cell fractures after installation through visual and IR-detected characteristics. Consider a professional cleaning service that provides warranty assurance.
Frequency1: Bimonthly to 6-monthly.
Heavy soiling (layered soiling not removable by water): Prevention is the best cure. However, aspects that cannot be prevented require maintenance. Where excessive soiling is present, cleaning your solar panels as much by water alone is essential to avoid soil layering. Should this be unachievable, monitoring build-up levels alongside the system’s energy output and factoring in a routine cleaning maintenance schedule from a professional company is advised. Consider a professional cleaning service that provides warranty assurance.
Frequency1: Monthly to bimonthly
Cleaning solar panels by environment
Soiling levels are often determined by varied environmental locations. The environment where your solar panels will often have an impact on solar panel cleaning requirements. Consider the following environments in Western Australia.
Oceanic environments (within 1 km of the ocean): We’ve ensured your supplied solar panels by PSW are IEC salt mist resistant, ensuring they can withstand the corrosive effects of heavy salt mist. Your solar panels are considered self-cleaning by rain unless heavy soiling is present in the area. Aspects considered ‘heavy soiling’ for oceanic environments:
- Bird excrement
- Environmental matter
- Visual salt build-up
High-dust environments: Environments subject to high dust levels are considered
self-cleaning by rain. Should rain not be present for an extended period (one month), good practice is to rinse your solar panels with clean water from a hose to simulate rainfall and prevent the potential of soil layering. Environments considered subject to high-dust environments where extra attention is recommended:
- Agriculture
- New building development zones
- Mining
- Rural
- Semi-rural areas
- Metropolitan fringe locations
Recommended cleaning: Monthly
Industrial environments: Environments subject to increased levels of carbon pollutants within a densified area should consider simulated rainfall should an extended period of drought remain present (monthly). Similar to how a car builds up dust on the outer layer when driving for an extended period without rinsing in industrialised/ heavily built-up areas. A solar panel surface accumulates similar soiling in heavily industrialised regions should rainfall be absent for an extended period. Even though less impactful initially, the objective in this instance is to prevent layering. Soil layering occurs when the environment produces the effect of hardening grime in periods of extended drought or insufficient rainfall. Industrialised environments include:
- CBD (Central Business District) areas
- Industrial zones
- Residential environments on a fringe CBD or Industrial zone
Solar panel cleaning questions
Not on a visually unsoiled array. Performance increases related to cleaning lightly soiled solar
arrays are more directly related to a cooling effect associated with water, normalising the cell
temperature to a less resistive operating temperature for electrons to flow, similar to Standard Test Conditions, 25°C, where the solar panel operates at peak performance.
When supported by adequate safety mechanisms and equiped with appropriate training, less is more. Avoid harsh chemical or abrasive interference to ensure the product integrity
remains intact. Reducing human interference with solar panels after installation compliments
manufacturer warranty certainty if adequately maintained.
1. Frequency is subjective based on the affecting environment and determination of the soiling. PSW Energy provides a free remote determination service for PSW Life Support customers. Send a photo of the affected solar panels to support@pswenergy.com.au with the subject ‘[P-Number] Solar Panel Soiling Determination Request’. Your PSW P-number is exclusive to your project with PSW Energy, providing free PSW Life Support access. Example: P-12345678 Solar Panel Soiling Determination Request > Report your querires > attach your images > Based on your P-number, we’ll have your system information and can cross reference the photos with the monitoring connected performance data. Please allow up to 5 business days for an assessment.