Wal-Mart Solar Fires: What Happened?
If you pay attention to energy news, you may have heard about a series of fires on the roof of Wal-Mart stores, caused by faulty solar panels. For those considering installing solar panels on their home or business, obviously, this is a worry. So, the basic question is: Are solar panels safe?
What Caused the Wal-Mart Fires?
According to a lawsuit filed by the company, the fires were caused by poor installation and/or maintenance of leased solar panels. Of the seven fires, three happened in the spring of 2018, two of them within a week. A number of problems were identified, including hotspots on panels that were damaged during installation, loose connections, and improper grounding.
In other words, the fires were caused not by anything inherent in solar systems or even in the systems Wal-Mart had installed, but rather by incorrect installation and maintenance performed by unqualified labor. In particular, it was found that unqualified staff were marking hotspots with electrical tape, causing a difference in solar absorption that could make the hotspots worse. Although the number of fires was low, PV panels should not be starting fires in the first place. Wal-Mart is now working towards removing 240 roof top systems that may have the same problems, ideally before another fire. The company that installed the panels was using less experienced, cheaper, contract labor and not providing the workers with proper protocols to follow.
What Qualifications should Installers Have?
First of all, you should choose a solar company that avoids the use of temporary labor. Companies invest more in full-time employees, and this also means you can feel better about how the installers are being treated. Trained installers are not expendable and employee turnover is expensive, so good companies will take steps to retain their staff over the long term. This then increases the number of experienced employees available, and allows the company to train new staff effectively.
Most solar installers are trained on the job, so find out about the company’s training program. Some states require certification. Make sure that the company you choose follows the rules. Because solar is a relatively new industry, the regulations are a long way from being standardized. There is nothing wrong with asking questions like how long the lead installer has been with the company. Choosing an established company helps, due to the fact that there are few certification courses for installers and most need to learn the old fashioned way. Newer companies may find it hard to attract experienced talent.
A good company also has solid procedures in place for installation, including checklists to ensure everything is done correctly and in the right order. They set their people up for success, and have tested and proven their procedures over the years. This also means the installation can be done more quickly, saving you money. In short, the best way to ensure that your solar system is safe is to hire a reputable installer.
What Makes Solar Systems Less Prone to Fire?
A correctly installed solar system is actually not particularly prone to fire. Modern systems have internal safety systems that are designed to shut the array down if a fault is detected. NEC 2017 requires that systems be equipped with a rapid shutdown that renders the array voltage minimal, which helps protect firefighters if there is a fire. There are some systems which can make your solar panels even safer:
- As already mentioned, rapid shutdown systems, which help protect roofers and firefighters. The best are built into the system, and are automatic, shutting down the system themselves.
- A state-of-the-art SolarEdge system. Modern inverters can monitor the array at the panel level, which mitigates the impact of shade. Shade can otherwise cause hotspots that can cause a fire. In addition, if a fault is detected, the entire system is de-energized.
- Avoid installing new panels on an aging roof or one which needs a lot of work. Do the roof work first. Ideally, your new roof should have a noncombustible layer.
- Have your system inspected regularly. For leased systems, this is generally part of the lease deal. If you purchased your panels, then make arrangements for the original installer to come back and do your inspections. Solar panels require little maintenance, but should be checked for rodent damage, etc.
- Keep your solar panels clean. This generally means hosing them off two to four times a year, depending on your climate. It is particularly important to clean them in the fall so they do not become covered in leaves. This also ensures that they remain effective.
- As already mentioned, ensure that the personnel doing the installation are fully trained and experienced, and that they have procedures to follow to make sure that the installation is done correctly.
Solar modules rarely start the fire when installed properly. The measures above, however, will also ensure that your system runs at full efficiency throughout its life.
Are Solar Systems Safe?
Absolutely. As long as your solar system was installed by a qualified, reputable installer. Even older systems that lack module level electronics are unlikely to catch fire when installed properly. Solar panel systems are properly tested to ensure that they have minimal fire risk, and experienced installers know how to design a safe and efficient system for any roof, regardless of configuration or materials. Many images of burned solar panels are the result of a fire that started elsewhere and spread to the solar system, with very few being a problem with the system itself.
To find out how mtvSolar ensures that our solar systems are installed correctly and are not going to catch fire, or to schedule a consultation, contact us today.