February 2, 2021

Rooftop fires and solar: what is the risk?

Can solar panel systems cause rooftop fires? A front page article in the Sydney Morning Herald today suggests there has been an increase in rooftop fires in recent years. Fire and Rescue NSW Superintendent Graham Kingsland says fires start in the direct current (DC) isolator switch, usually because of water getting in. The cause of rooftop solar fire risk is faulty installation or manufacture.

We asked David Veal, owner of Clean Energy Council-accredited company Solarpro, whether solar panel owners should be worried.

David’s take:

There are two reasons these isolators catch fire. First, water gets through the fitting because it is badly glued or not glued at all. Second, the wiring is not done correctly and left loose, or the polarity has been crossed.

Take a look at these two roof top isolators.
Fire risk DC isolators

The isolator on the left is the cheaper of the two by almost $30. I have put some of the fittings below it. These are screwed and glued into the little glands above them. The cables are then fed into the fittings and manually wired into the isolator. This is fiddly and time-consuming. It is a perfect trap for human error.

All cheap companies use these isolators because they are scrimping and saving every dollar. Plus the contractor pays for the extra time wiring them up. 

Quality costs a little extra and the devil is in the detail!

The isolator on the right is factory pre-wired, so it is guaranteed to be wired correctly and will not leak. At Solarpro we use these as our standard rooftop isolator and have done since they became available in 2014. With pre-wired ones the installers cannot get it wrong.

The conclusion: a badly-installed, cut-price DC isolator could be a rooftop solar fire risk. But if you use an experienced CEC-accredited installation specialist you can rest assured it will be well-installed and of good quality.

Zero Emissions Sydney North runs regular information sessions, via Zoom and in person, hosted by volunteers. We design them to help people make the switch to using renewable energy and rooftop solar.

Our next Solar My House Info Session is on Wednesday, February 24, from 6.30-7.45pm. David from Solarpro will be our expert guest speaker. Attendance is free but places are limited, so sign up here as soon as possible. 

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