Are Solar Panels Waterproof?

Let’s face it; solar panels take a beating from the elements! These solar electrical generators need to be pretty sturdy to stand up to the weather between the sun, the rain, the snow, high winds, and hail!

Solar panels are waterproof as, without a watertight seal, liquid seeping into the panels would wreak havoc with the generation of electricity, not to mention cause short circuits and disruption to the energy flow to the batteries – plus, the rain helps to maintain them!

Let’s examine why and how solar panels keep water out:

  • How solar panels keep water out
  • How the rain and other water help to keep them clean
  • What would happen if water leaked into the panel

Waterproofing in solar panels is a critical aspect of their performance in keeping your home powered up from the sun, so let’s shine some light on how waterproofing in solar panels works.

Water on solar panels being washed

How Are Solar Panels Waterproofed?

Solar panels are built to be waterproof using a combination of glass, plastic, and a highly efficient sealant.

Solar panels, by design, are watertight, and this would be one of the very first design elements engineered and created before building the first panel. Because they are exposed to the mercy of the elements and various intensities of precipitation, hyper-effective waterproofing is an absolute.

The panel’s design on the outside uses a thin but tough sheet of glass on the front and a highly resistant and durable sheet on the back. This back sheet is usually made of a polymer-type material, virtually impenetrable by water.

The metal frame that holds the sheets and the internal components is sealed with specially designed glue that prevents water from entering the solar panel enclosure. Combining all of these elements gives you a waterproof electrical powerhouse!

Another clever part of the design is that the glass is often coated with chemicals that prevent water from bonding to it and optimize photon collection.

But, the design is not the only way that solar panels are protected against water; their installation also plays a role.

How The Installation Of Solar Panels Helps Water Resistance

Solar panels are placed on the roof at an angle. While many people believe that this is to optimize solar capture, it allows water to run off and reduces the risk of penetration into the panel enclosure.

If you have ever watched solar panels being installed, whether live or on video, you will know that they are very seldom, if ever, placed flat on the roof. This is because there is an optimum angle required for solar capture.

Angled panels provide a more significant opportunity to capture every bit of sunlight that falls on them, but there is another reason they are angled.

The glass on the front of the solar panel is super-smooth, and virtually nothing will stay on there for very long, including leaves and, of course, rain. The water cannot remain on the panels when it rains due to the angle and runs off onto the roof.

See also: 13 Advantages + 5 Disadvantages Of Solar Energy

How Solar Panels Waterproofing Keeps Them Clean

Solar panels would slowly lose their capacity to generate electricity due to dust and other debris without rain and snow. The water runs down the panel surface when it rains or snows, removing the surface dust and other accumulated debris.

Solar panel designers are pretty intelligent. One of the challenges they faced was keeping their panels clean without having the owner climb onto his roof every time it rained or snowed to clean the panels and ensure they kept working.

Having a treated glass surface and polymer back plate allows rain, snow, and other airborne moisture to run off the glass without sticking or creating dust tracks, which would result in lower generational output as the photovoltaic cells become obscured from the sun.

This effectively cleans the panel, and while there are times when a proper and more thorough clean may be required, for the most part, the rain and snow wash off the accumulated dust and debris and maintain generational capacity.

When it rains, the force of the water hitting the panel but not being able to adhere to it creates a strong current flow down the glass, and this ‘washes and rinses’ the surface of the panel of dust and dirt.

Similarly, the back panel also has a wash and rinse, but there is less run-off because it doesn’t face the rain directly.

While snow can accumulate on solar panels during heavy snowfalls, it usually melts soon enough, and again, as melting snow turns to water, it runs down the surface, taking any dirt and dust with it.

Now, this doesn’t mean that you shouldn’t have your panels cleaned every year or so, but for the most part, the rain and snow (if you have it) will do the job nicely for you at no extra cost!

And here’s another benefit to having water flow over your solar panels- it cools them down, making them more efficient! Because solar panels operate more efficiently at cooler temperatures, having water over your panels can boost production!

What Would Happen If Water Penetrated A Solar Panel?

During manufacture, every measure is taken to ensure that all produced panels are 100% waterproof. But, as with any product, sometimes there can be defects.

If the back and front glass sections are not seated correctly, or the sealant doesn’t seal properly, there is a risk that water could enter the panel.

If this happens, it could create a short circuit between the polarities, and extensive flooding could jeopardize the core components, drastically affecting the panel’s ability to generate electricity.

The panel could fail altogether in severe cases as individual PV cells could get damaged or destroyed. Remember that even though solar panels are waterproof, they are not designed to be submerged as water pressure could cause water to leak into the casing.

Should you find that one of your panels has been compromised and water has managed to permeate the panel’s seal, your warranty will cover this, and your supplier or installer will replace the panel.

A tiny gap in the external waterproof seal would most likely be manufacturing or possibly even an installation fault.

Because solar panel manufacturers have very stringent guarantees and warranties against defective workmanship, it would not cost you anything to have it replaced and reinstalled.


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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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