Can I clean my solar panels myself? Risks, safety and warranty

If your panels are on the ground, on a low pergola or on an accessible structure, you can keep them clean yourself with some basic precautions. But in most homes, farms and industrial buildings the panels are on the roof, and that changes things. These are the three risks worth knowing about before you climb up.

Risk 1: falling

A wet tiled roof, a metal-sheet roof or a fibre-cement sheet are not designed to be walked on. Falls from height are one of the main causes of serious accidents in construction: Spain's National Institute for Occupational Safety and Health (INSST) has published a dedicated report on them [4].

For workers, Spanish regulations require specific equipment and procedures for temporary work at height [2][3]. In practice, professional work on a roof is carried out with:

• A lifeline, fixed if the installation already has one, or portable if not.
• Certified harness and helmet.
• A mobile elevating work platform (MEWP) or certified scaffolding when access requires it.

Risk 2: electric shock

As long as there is daylight, panels produce electricity, even if you switch off the inverter. First Solar's cleaning guidelines are clear: the voltage and current present in an array during daylight hours are sufficient to cause a lethal electric shock [1]. That is why the manufacturer asks for:

• Cleaning to be done only by trained personnel who understand the risks of applying water to electrical components.
• A prior inspection for cracked glass, damage and loose connections.
• Cleaning with the installation in open circuit or with the inverter off, and preferably in low light.

Risk 3: damaging the panel and losing the warranty

Solar panels come with long performance warranties, but on condition that they are installed, operated and maintained as the manufacturer specifies. In First Solar's case, its guidelines warn that failing to comply with them may void the warranty, and that modules damaged by the cleaning method are not covered [1]. The most common mistakes are:

What you can do yourself

• Check production in the inverter app every month.
• Look at the panels from the ground, a window or a terrace.
• If they are at ground level, rinse them early in the morning with low-hardness water, without products or pressure.
• Call a professional if you see broken glass, loose cables, nests or a clear drop in production.

Conclusion

Cleaning panels is not difficult, but doing it on a roof is dangerous. If your installation is at height, the cost of a professional clean is small compared with the risk of a fall, an electric shock or losing the warranty on equipment that should last more than 25 years.

About the sources: the water quality, pressure and temperature figures in this article come from the cleaning guidelines of First Solar, one of the largest US manufacturers of solar modules, which makes thin-film modules; silicon modules, more common on rooftops, may have slightly different specifications. Each manufacturer publishes its own, which is why at TARRAMED we always follow those of your panels' manufacturer.