As the adoption of solar energy continues to rise, so do questions about its safety. One of the greatest concerns is fire risks.
Headlines about solar panels catching fire can understandably lead to hesitations and anxiety among homeowners and business leaders. In 2022, an article published by CNBC revealed that Amazon took all of their rooftop solar panels offline due to continuous electrical explosions. However, of the 259 major findings across Amazon’s rooftop solar portfolio, the problems identified can be attributed to faulty equipment and installation. As outlined in this article and discussed further in this blog, there are various potential causes of fires and effective strategies to significantly reduce those risks.
While these incidents are very rare, fires can happen. That’s why it’s critical to understand the factors that can contribute to potential fire hazards and how to minimize those risks.
In this blog, I will break down the fire risks associated with solar energy, explore preventative measures, and provide expert insights to help you make informed decisions about your solar panels.
Are Solar Panels Flammable?
One of the most prominent questions surrounding safety concerns with solar panels is whether they are flammable.
The short answer is nothing is inflammable when subject to high enough temperatures. That being said, when one reads through the CNBC report, the independent findings indicate that the cause of the fire included mismatched module-to-module connectors, improper installation of connectors, poor wire management and evidence of water intrusion in the inverters. These issues are not the fault of the hardware. The fires resulted from improper installation techniques. In my ten years of working in the solar industry, I have seen no documented cases of solar panels spontaneously combusting from overheating or for any other reason. I have seen instances where improper installation techniques caused equipment damage, and in rare cases, fires. It is vitally important to choose a solar installer who understands the code requirements to safely install solar panels and inverters, who has invested the time required to train their personnel properly, and who has invested the capital resources to purchase the require tools and hardware that are required to properly make module connections using like kind and approved module to module connections.
What Makes A Solar Panel?
The makeup of solar panels includes an aluminum frame, a glass front sheet, encapsulant, silicon cells, and a plastic back sheet, most of which are non-combustible materials. As stated before, nothing is inflammable when exposed to high enough temperatures. The plastic back sheet has a lower combustion temperature than the other materials of a solar panel.
The combination of aluminum and glass provides the panel with durability while the silicon cells effectively convert sunlight into electricity, without posing a fire risk. The robust makeup of the panels are designed to perform consistently in diverse weather conditions, making them a safe and effective option for harnessing solar energy.
How Bypass Diodes Prevent Fires
One important safety feature in modern solar panels is the inclusion of bypass diodes. These components play a crucial role in preventing overheating, which can lead to fire risks.
How Bypass Diodes Work
Solar panels generate electricity by allowing sunlight to flow through the photovoltaic cells. However, when a part of the panel is shaded or obstructed by debris, such as leaves, dirt, or snow, that section may be prone to overheating or creating a hotspot. Without the bypass diode, the energy would try to flow through the obstructed circuit, resulting in overheating, which could pose a fire hazard.
The diode reroutes the electrical current around the blocked area of the panel, ensuring the system operates efficiently without the risk of overheating. Thankfully, most current solar panels contain bypass diodes, but it is important to ensure yours do to significantly decrease this risk.
What Causes Solar Panels to Catch Fire
So if solar panels are made up of non-flammable materials and include safety features like bypass diodes, creating an additional level of security against fires, what could cause a solar panel to catch fire?
Improper Installation
The primary and most significant factor in rooftop fires is improper installation. If an installer does not use properly listed connectors, required by The National Electric Code (connectors that are compatible with each other), the chances of a fire risk are significantly higher. It is highly recommended to go with the safest option and use connectors made from the same manufacturer, lessening the risk of failure significantly. A notable portion of connector failures can be traced back to mismatched components. The use of quality components and trusted installers are critical factors to ensuring a system’s safety and profitability. This notion emphasizes the importance of adhering to the guidelines of The National Electric Code and hiring a reputable installer who will adhere to the mandated guidelines.
Damaged connector due to improper installation.
Inadequate Design
The design of a solar panel system is crucial for preventing fires because it ensures that all components are safely integrated and function properly.
Another vital aspect to consider regarding fire safety in solar systems is the proper design of the system. There are several design flaws that could increase the likelihood of creating a fire risk. Having a system individually designed for each roof allows for the proper design of the circuit and wiring on the roof, so that the proper allowance for the amount of current and voltage the PV wires are carrying has been considered and integrated into the overall system design, while adhering to NEC standards. If conductors, connectors and equipment are not properly sized according to NEC requirements, DC and AC circuits may be overloaded without the appropriate fuse or circuit breaker integrated into the circuit to maintain safety. When a system is exposed to more power that it can safely manage, it can lead to excessive heat buildup and equipment failure. Similarly, the use of faulty or low-quality components can compromise the entire system’s integrity. Components that fail to meet safety standards may overheat or short circuit, posing a serious fire risk. When buying components for a large investment like solar, it is highly recommended to go with trusted brand names who have a reputable history. Paying more money upfront is well worth the investment for your safety and to protect your investment. I like to say if it’s cheaper, it’s probably cheaper for a reason.
Wire Management
Another potential fire hazard stems from poor wire management. Wires from solar panels must be properly restrained to prevent rubbing against the roof, which can lead to exposed wire and, therefore, a fire hazard. Using the correct type of stainless steel clips is essential for maintaining integrity in the system and preventing the wires from being an issue.
In this picture, the wire isn’t securely fastened, causing it to rub against the roof. Over time, this friction will weaken the wire and create a safety risk.
Environmental Factors
For solar owners located in wooded areas, environmental factors can pose a risk as debris can accumulate on roofs and cause concern. It is recommended to have your installer include a Critter Guard, a mesh barrier that prevents rodents from creating nests and under the array where leaves and other flammable materials could accumulate. If incorrect connectors or installation techniques have been used, a hotspot or failed PV connector will have flammable material near it that could lead to a potential fire risk.
Critter Guard Installation Around Solar Panel System.
How To Reduce The Risk of Solar Panel Fires?
While solar panel fires are rare, it’s important to take proactive steps to minimize the potential risks. Here are some proactive measures to consider.
Use of Listed Equipment
Listed equipment is designed to meet stringent safety standards, reducing the risk of electrical hazards. When connectors or other components are not listed, it significantly increases the likelihood of electrical issues, such as overheating, arcing, or short circuits, which can ultimately lead to fire risks.
It is essential to ensure that the installer of your system is using equipment that is “listed”, meaning it has been tested and certified for safety and compatibility. When connectors or other components are not listed, it significantly increases the likelihood of electrical issues, such as overheating, arcing, or short circuits. This is a requirement from The National Electric Code and is enforced to help reduce the chances of fire danger. Working with a qualified installer who adheres to these guidelines is mandatory for achieving a safe and efficient solar energy system. The use of high-quality components from reliable suppliers is also crucial to ensure the overall safety, efficiency, and longevity of your solar energy system. The quality of the components used greatly impacts the system’s overall performance and lessens the chance of electrical issues.
Properly Designed
A properly designed solar system is necessary for reducing the risk of fire hazards. When a system is correctly engineered, components are appropriately matched, and circuits are not overloaded, minimizing the potential for overheating. Poorly designed systems can strain wiring and increase the likelihood of electrical faults. It is also vital to ensure that your modules include a bypass diode which protects from overheating in shaded or obstructed cells. Following the guidelines for system design set by The National Electric Code and working with an experienced installer ensures your system meets safety standards, ultimately lowering the chance of fire risk and enhancing overall reliability.
Regular Maintenance
Having regular maintenance of your solar system is one of the easiest and most effective ways to reduce fire danger. You should schedule annual inspections to check for debris accumulation, damaged wires, or other issues that could pose risks. Keeping your solar system clean and well-maintained will ensure safe and productive energy production.
Protection Against Environmental Factors
One way to combat environmental factors is by installing a critter guard. Critter guards act as a barrier between the solar panels and the roof, blocking animals from getting underneath the panels and preventing buildup of nests and debris. I have seen many systems where animals have accessed the area beneath the panels, causing damage by scratching off existing shingles and chewing through the insulation on wiring. This simple addition can greatly reduce the risk of fire by keeping potential flammable materials away from the actual panel.
 Chewed Wire From Rodent p |
 Debris Buildup |
How To Shield Your System
In the rare event that your solar panel system encounters a fire-related issue, having proper insurance coverage is essential. Solar panels are a major investment, and just like any significant addition to your property, they should be included in your insurance policy to shield you from unexpected financial setbacks.
For those in the Mid-Atlantic region who want to ensure their solar investment is safeguarded, consider our Paradise Protect Service Plans. These plans offer peace of mind and comprehensive protection for your system. Our experienced solar maintenance team is also ready to assist with any issues, ensuring your system operates safely and efficiently.
