Solar Mythbusters Episode #3: Solar Danger Part 1 – Toxic Fumes from Burning Solar Modules

House fires. A terrifying calamity that puts life and property at risk. A few years ago we were working with a customer who was interested in leveraging the savings of solar. The economic benefits were clear, and the customer was ready to move forward. That was until they convinced themselves that in the case of a fire, burning solar modules would produce toxic gasses which would be an unavoidable and deadly threat to their family. The myth we cover in this episode: fumes caused by burning solar panels in a house fire are a deadly threat.

The myth…

In the case of a house fire, rooftop mounted modules that are exposed to the heat of the fire will create an unavoidable and deadly toxic fume risk.

Solar Mythbuster Investigation & Response…

Lets frame the situation:  Consider a house with solar on its roof. A fire breaks out inside the home in a place such that the solar panels are at risk of being exposed to fire. Furthermore, assume the fire progresses to the point where the panels are actually exposed to fire.

Scenario 1: Lets assume the unfortunate case that the inhabitants are inside the building. In this case, because the modules are on the roof and heat rises, any toxic gasses would whisk up into the sky. The fire heated column of hot air would not usher gasses downward.

Conclusion: Even if toxic gasses are produced, its unlikely that it will make its way to where the inhabitants are. The story may be different for firefighters on ladders above the roof, or generally closer to the fire itself, but they are trained professionals armed with respirators.

Scenario 2: Lets assume the likely scenario that the inhabitants evacuate. In this case, just as in scenario 1, toxic fumes would be ushered upward to the sky while the inhabitants maintain safe distance at ground level.

Conclusion: same conclusion as for scenario 1.

Ok… but what about the toxic fumes?

Well here, I had a little help. It turns out that this topic has already been covered:

Because solar panels are encased in heavy-duty glass or plastic, there is little risk that the small amounts of semiconductor material present can be released into the environment. In the event of a fire, it is theoretically possible for hazardous fumes to be released and inhalation of these fumes could pose a risk to human health. However, researchers do not generally believe these risks to be substantial given the short-duration of fires and the relatively high melting point of the materials present in the solar modules. Moreover, the risk of fire at ground-mounted solar installations is remote because of the precautions taken during site preparation including the removal of fuels and the lack of burnable materials – mostly glass and aluminum – contained in a solar panel.

Solar Mythbuster Conclusion: Its extremely unlikely that inhabitants would be exposed to fumes. And, while solar panels aren’t really flammable, they could outgass if exposed to sufficient heat over a sufficient period of time. Even then, they are not expected to produce much in the way of fumes because they are largely made from aluminum and glass.