Are Solar Panels Waterproof?

Solar panels convert sunlight into electricity. In order to do this, they need to be in an open area with as much exposure to the sun as possible.

This also means that they will be exposed to the elements. One of the most important elements that they need to be protected from is water.

In general, water exposure isn't something unexpected for solar panels. In fact, solar panels are designed considering they will be in direct contact with rain and snow.

However, is that make them waterproof?

The answer is Yes. Solar panels are waterproof provided they have been chosen for the specific application and installed correctly.

They will not allow water intrusion that may damage and/or disrupt the electrical circuit. In achieving this, most panels are typically tested in a laboratory setting simulating different types of weather conditions.

As a result of these tests, products achieve an Ingress Protection (IP) rating. The higher the IP rating, the more resistant the product is to water and other elements.

It is important to note that IP ratings are given to a product by independent laboratories that test the product under specific conditions. Thus, buyers should not rely on self-claimed ratings by manufacturers.

Instead, they should always request a copy of the official IP rating report from the laboratory unless the rating is included in the product's specification sheet.

This takes us to the realization that the term “waterproof” isn't a single definitive term that a product is either classified as or not. Instead, when a product is referred to as waterproof, it means that it can withstand water exposure under specific conditions.

How to interpret IP ratings in regards to water exposure?

As we have just mentioned, IP ratings are given to a product by independent laboratories that test the product under specific conditions. These ratings can be used to determine how water-resistant a solar panel is.

IP ratings are two-digit numbers and each digit has a specific meaning. The first digit is the protection against solid objects and the second digit is the protection against liquid objects.

For example, a solar panel with an IP rating of “IP65” rating would have better protection against water than a product with an IP rating of “IP64”.

Because both ratings start with a “six” (which is the highest rating), this means that both products are highly resistant to the ingress of dust (dust-tight).

However, the “five” in the IP65 rating means that it is protected against low-pressure water jets from all directions, whereas the “four” in the IP64 rating means that it is only protected against splashing water from all directions.

Thus, the IP65 product would be better suited in an area with more rainfall or snowfall. Because IP65 rated products are able to protect against water jets.

Now let's take a look at what different IP ratings mean in terms of the water resistance of solar panels.

IP65 Solar Panels

IP65 solar panels are the most common type of solar panel on the market. They are rated as “dust tight” and can protect against low-pressure water jets from all directions.

IP65 testing is done as below.

When executing the testing the laboratory projects a water jet by a nozzle (6.3 mm) against enclosure from any direction to check if water is able to enter. If the product can pass this test, it will be given an IP65 rating.

With this test method, the test duration is set as a minimum of 15 minutes where water volume is 12.5 liters per minute. The pressure is set as 30kPa and applied at a distance of 3m.

It is also important to keep in mind that the IP rating only refers to the product and not the installation. Buyers should always consult with an electrician to ensure that the entire system is properly installed and protected.

IP66 Solar Panels

The next higher IP rating is IP66. Products with an IP66 rating are protected against powerful water jets from any direction.

Executing this test, the panels are projected with powerful jets of water (12.5 mm nozzle) against the enclosure from any direction.

Testing duration for this method is set to be at least 3 minutes, while water volume is 100 liters per minute. The water jet is applied with 100 kPa pressure at a distance of 3m. If the product can pass this test, it will be given an IP66 rating.

IP67 Solar Panels

IP67 solar panels are also high on the list of waterproof solar panels. IP67 means that the panel is dust-tight and can withstand being submerged in 15 cm to 1-meter water for thirty minutes.

When the enclosure is immersed in water under specified pressure and time circumstances, there should be no ingress of water in a harmful amount.

This testing is applied for 30 minutes. The immersion at depth is set to be at least 1 m measured at the device's bottom and at least 15 cm measured at the device's top.

IP68 Solar Panels

The highest rating that a solar panel can achieve for waterproofing is IP68. This rating means that the product is dust-tight and can be submerged in water for long periods of time. IP68 rated solar panels can be used in areas with high water pressure, such as permanent underwater solar applications.

What parts of the solar panel are more prone to water intrusion?

Solar panels aren't only just solar cells, glass, and metal frames. There are other parts of the solar panel that should be taken into consideration when thinking about waterproofing.

Here are the three main areas where water could potentially enter the solar panel and cause damage.

Backsheet

Backsheet is the material located on the back of the solar panel. This is usually a polymer film that helps to keep moisture and water out of the electrical components. However, sometimes, water can seep in through the back sheet.

This can be due to low-quality materials or improper installation. If water seeps in, it can cause corrosion and damage to the electrical components. In fact, most solar panels develop water damage due to a faulty back sheet unless they don't have a crack.

Because the backsheet is located on the back of the panel, the problems with it are often not noticed until it's too late.

Junction Boxes

The junction box is where the solar cells are interconnected and where the electrical current is collected. This part of the solar panel is usually made out of plastic or metal and contains a sealant to keep the water out.

If the sealant is not effective, then water can easily get into the junction box and cause damage to the electrical components.

Connectors

The connectors are what connect the solar panel to the rest of the electrical system. Since they have to serve as an interface between different materials, they are usually made in form of male and female connectors.

This form of the connector can make it easy for water to get inside and cause damage if they are not properly sealed.

What type of solar panels are best in waterproofing?

Monocrystalline and polycrystalline solar panels will usually be more prone to water ingression than thin-film solar panels.

This is because the crystalline panels are built with multiple layers that are all sealed together. If one of the seals is broken, then water can easily get in and cause damage.

Thin-film solar panels, on the other hand, are made with a single layer of material. This makes it more difficult for water to penetrate through the material. However, thin-film solar panels are not as efficient as crystalline solar panels.

If you're looking for a waterproof solar panel, then you should consider getting one that has an appropriate IP rating for your needs.

There are glass-on-glass solar panels that don't have any back sheet. These panels are built by sandwiching the solar cells between two layers of glass.

This makes the panel more durable and resistant to water damage. However, these panels are more expensive than traditional solar panels.

How to prevent water damage to solar panels?

Obviously, the very best way to prevent water damage to solar panels is by using a panel that has been tested and certified for the specific environment in which it will be used.

But there are other ways to minimize the risk of water damage as well.

Use aquarium sealant

Aquarium sealant is typically made from a type of silicone material that is designed to create a waterproof barrier. When applied to a surface, the silicone material cures and forms a rubber-like seal that is impermeable to water.

To use aquarium sealant on a solar panel, the surface of the panel must be clean and dry. Any debris or moisture on the surface can affect the effectiveness of the sealant.

Once the surface is clean and dry, the sealant can be applied to the edges of the panel using a caulking gun or another similar tool.

When the sealant is applied, it fills any gaps or spaces between the edges of the panel and the junction box or electrical connectors. This creates a tight seal that prevents water from penetrating the panel and causing damage.

It is important to note that aquarium sealant should not be applied to the solar cells themselves, as this can reduce their efficiency. Instead, it should only be applied to the areas where it is needed most, such as the edges of the panel.

Install solar panels under a transparent patio cover

Installing solar panels under a patio cover is a great way to protect them from the elements. The patio cover will keep the rain and snow off the panel while still allowing sunlight to reach the solar cells.

Yes, there will be a slight reduction in the amount of sunlight that reaches the cells, but it's worth it to protect your investment. Here is our post explaining how solar panels work through the clear plastic.

It's also a good idea to install a gutter system around the perimeter of the patio cover. This will help to keep water from pooling around the base of the solar panel and causing damage.

Use a tarp

Although using a tarp will defeat the purpose of having a solar panel in the first place, it's still an effective way to protect your panels from the elements.

If you know that a serious storm is coming and you won't be able to remove the panel in time, then cover it with a tarp. Be sure to secure the tarp well so that it doesn't fly away in the wind.

Conclusion

Solar panels are waterproof since they are intended to be outside and exposed to the weather. For most installations, there is no need to worry about water damage.

However, if you live in an area with occasional severe weather conditions, then you may want to consider getting a solar panel that has been tested and certified for your specific environment.

There are also a few things you can do to prevent water damage, such as using aquarium sealant or installing the panel under a patio cover. If all else fails, you can always use a tarp to protect the panel. Although this isn't the best solution, it can protect your investment during severe weather conditions.