Should I Be Worried About My Solar Panel Catching Fire? An Engineer's Breakdown
** I’m an Electrical Engineer with 15+ years of experience, 6 years in solar installation, and currently work at MPNG (a $100M a tech start-up). Having deployed solar systems nationwide, I started this blog to cut through marketing noise and deliver honest, engineer-grade advice.**
Firstly, Solar panels themselves rarely catch fire. It is reported that less than 0.01% of world-wide installations catch fire. The panels themselves are not flammable per-say and even if they combust, it's usually due to poor installation and bad components.
Here are the main reasons why solar panels catch fire:
DC Arc Faults:
Solar panels generate DC before it is "converted" into AC that can power your house. Depending on your solar setup, over 100v of DC might be generated by your panels.
High voltage DC is very dangerous and has more "arc" potential than AC, hence if there is a loose connection(partial contact) , or exposed cables due to rodents chewing on the wire, electricity can 'jump' through the air to bridge the gap forming an arc.
The arc burns incredibly hot at times over 3,000C which is enough to set any flammable material around up in flames
Loose or low quality Connectors
Remember the experience you get when you plug in that pressing Iron, toaster or electric cooker to a low quality socket? The melting and burning? The same can be said about solar installations: partial contact and/or connectors mismatch can add high resistance to the circuit potentially leading to overheating and fire.
Poor Quality or Damaged Components
It is not a good idea to keep on using or (managing) a cracked solar panel. The thing is that water can seep into the internal circuit of the solar panel leading to a short. Water and high voltage electricity don't go well as we all know.
Once you notice a cracked panel, it must be changed no matter the cost or it will cost you heavily later.
Localized Heating due to Debris or Shading
When a section of a solar panel is blocked from sunlight, due to perhaps a bird dropping or trees,; the blocked section cannot generate electricity, and as a a result it starts absorbing energy generating heat.
If this abnormal situation is left long enough it can burn through the panel causing a fire./
How to protect your system
Most importantly, never go cheap with a solar installation. " I know someone cheaper" usually doesn't end well for everyone involved. While it is a good idea to try to get the best value out of your investment, you should also know that there is a thin line between the best value and literal fire on your roof.
Make sure high quality cabling is used, high quality panels and connectors are non-negotiable.
Secondly, always make sure that all cables are covered and not exposed especially in areas prone to rodent presence. Proper conduit, trunking or/flex will suffice.
Lastly, ensure the panels are cleaned repeatedly and all shading addressed.