How To Seal Between Solar Panels (Do This!)

The installation process of solar panels cannot be complete without sealing between them. Unfortunately, most people forget this vital detail, and after putting up the panels, they neglect to seal them. 

Sealing between solar panels helps maintain their efficiency over time. Additionally, it lowers the risk of leaks that would otherwise result in severe damage in your office, business, or home.

This article guides you on how to seal between solar panels after installation to help maintain efficiency and effectiveness for a long time. 

Man installing solar panels connecting two panels
Man installing solar panels connecting two panels

Effective Ways of Sealing Between Solar Panels

There are several products designed specifically for sealing solar panels. You can also DIY, and as long as you do it the right way, it will turn out alright. 

These NPC #900 Solar Seal are specifically designed to work with solar panels and can handle the temperature differences you encounter. Click the image to see more about them on Amazon, once you’ve read how to seal them.

NPC #900 Solar Seal 3 Pack - for Metal Roofing Flashing/Panels, Vinyl and Fiber Cement Siding, Fiberglass, Cedar, Brick & Masonry, Sky Lights, Sun Rooms, Truck RV Trailers, Flashing (3, Clear)

The length of service your solar panel gives you will depend on the quality of the sealant. Most hardware stores stock industrial-grade silicone adhesive.

And although its primary use is to fill spaces around window seams or frames, it works great with flat surfaces of commercial-grade solar cells.

You can buy several cartridges, and after applying the amount you need, store the rest for future use.

A silicon sealer (of good quality) also does the job well. Just ensure it’s compatible with your solar cell because not all are compatible with different types of cells.

While you are free to choose whichever finish meets your needs, avoid oil-based sealers. These are not that friendly with solar panels and may react, resulting in serious problems later on.

How To Seal Between Solar Panels

Below is a step-by-step procedure of how to seal between solar panels using a silicone sealant:

  1. Clean the surface to get rid of tape or any other material before starting the sealing process.
  2. Add the silicone sealant at the point where the glass meets with the frame or whichever edge protection is present. Avoid applying too much sealant as it just goes to waste, flowing out after you install the panels back.
  3. Carefully add more silicone between the panels, if necessary, especially where you need to fill in the gaps. 
  4. Before reinstalling solar panels, ensure you remove any water on the inner side.
  5. Be careful not to tilt the panels during the sealing process. If water accumulates on these panels and drips to the inside, it can cause a short circuit.
  6. Use adhesive tape or silicone tape to hold the panels and everything else in place when reinstalling.

If you already have edge protection around the glass, silicon glue will get the job done. However, if you have no protection to the glass enclosure, consider using aluminum tape as a cover.

If you still feel like there will be some water leakage, the best thing to do is replace your panels with new ones.

See also: How to install solar panels (Detailed Step-By-Step Guide)

Why Is Sealing Between Solar Panels Important?

Sealing solar panels the right way ensures they keep working effectively for a long time. That’s why it’s advisable to go for high-quality sealants designed specifically for solar cells.

Also, choose a product that’s compatible with the type of cell you are using.

When working on the panels, ensure you take the necessary safety precautions. For example, ensure you have your gloves on. Remember, an unsealed system is a disaster waiting to happen. It may lead to various issues.

Water may find its way to the bottom, corroding your solar panel system or causing more damage with time.

Also, dirt build-up could block sufficient light from reaching the cells, resulting in reduced power output.

Therefore, if you want maximum productivity from your solar panels’ system, seal between your panels. There’s no shortcut.

How Often Should You Seal Between Solar Panels?

It’s recommended that you seal after every few years when necessary. Of course, the number of times you reseal will depend on how well you apply it the first time around. Another determining factor is the location of your panels.

Beforehand, clean the surface so that you don’t apply silicone or whichever compatible sealant you are using on top of the tape. This guarantees the sealant effectiveness for several years before you can reseal again.

How Do I Choose the Best Solar Sealant?

The best solar sealant must feature all the qualities that make a sealant material effective. In fact, it’s no different from any other outdoor sealant. At the minimum, the sealant must have the ability to:

  • Resist sunlight (UV rays)
  • Prevent moisture penetration
  • Resist corrosion in metallic electric components around it.
  • Act as a good insulator, preventing heat loss. It should also prevent excessive heat gain, something that degrades solar panels very fast.

Fortunately, most solar sealants available in the market are good UV-resistant agents. These hold solar cells in place and don’t cause electrolysis in the cells. Therefore, they are a good fit for your sealing needs.

NPC #900 Solar Seal 3 Pack - for Metal Roofing Flashing/Panels, Vinyl and Fiber Cement Siding, Fiberglass, Cedar, Brick & Masonry, Sky Lights, Sun Rooms, Truck RV Trailers, Flashing (3, Clear)

Types of Solar Panel Sealants

Solar sealants come in three major types. You can apply them by yourself or hire a professional. They include:

  • Silicones: These are pretty good, although they provide poor insulation, corrode solar panels after some time, and have poor heat-trapping abilities.
  • Polyurethanes: These are some of the best solar panel sealants you will come across. They are excellent UV-blocking agents, good heat insulators, and cheap to manufacture. Additionally, they don’t cause corrosion to electrical components and don’t allow any water to penetrate the inside.
  • Butyls: These are better at preventing moisture penetration and UV light than polyurethanes. And while they provide excellent insulation, they tend to be tacky at room temperatures, making it hard to use them correctly. However, they are the most popular type of sealant due to their availability and affordability.

What Is the Average Life of Solar Panel Seals?

Seals should serve you for five to seven years on average without requiring replacement. However, factors such as the installation size and extent of exposure to weather elements determine how fast you have to reseal.

Butyls are more durable than silicone sealants, but with age, they need replacing. That’s because the infiltration of rainwater and high UV exposure damage them.

It’s important to note that you don’t have to replace your panels simply because you’re replacing a degraded sealant. 

Also, if you cannot seal between solar panels yourself, always seek help from a professional.

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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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