Australia has the proportionally the greatest number of roof panel installs than anywhere else and their incidence rate is 0.01% of installs. The panels’ themselves are not the cause but poor quality workmanship around connections. In particular the use of pairing up of different makes of MC4 connections and poor or underrated DC switchgear. Most panel manufacturers fit flying leads to connect to each other, so that is covered, the issue can be the end of the string being mated up to the continuation cable to the inverter using a different make of MC4. I saw something this week about the tightening up of the use of DC switchgear (not sure if it was a guidance or regulation) because they have been recognised as a weak point in installs DC being more demanding of switchgear quality than AC due to the arcing potential. A recommendation was to have minimum number of DC isolators in a system. The concern here with the roof fire, as highlighted, is this a one off or is there potentially a systemic issue with the other builds on the estate.

The report in today's Mail suggests a couple of causes. Leaves or other debris behind the panels, presumably over-heating and combusting, and/or the gap between panels and tiles being presumably, too little.

I don't have panels, and have no plans to fit them, but if I did, I prefer the flush appearance. With no 'open to the air' gap behind flush panels, can that be a problem?

Posted By: djhWhy is there this notion of an "explosion"?

Because it's the Daily Mail.

What I saw in the video clip, presumably from a neighbour’s camera, looked like an explosion, could have been edited I suppose to make it look more dramatic. Must be really stressful for the occupants a new house being almost destroyed in a blink of an eye but at least there were no injuries. Our solar panels are in a field 80M away and the inverter batteries and supporting stuff are in an outhouse. Only AC comes into the house.

Oh great. Have replaced all my old panels and micro-inverters with a conventional system due to regular failures of the micro-inverters!!

However I did ask that the inverter be placed in the garage and not in the loft (which I think the installer would have preferred for ease of installation), because I was concerned that it would be out-of-sight and out-of-mind up there. The garage is north facing and never gets hot even during the recent heatwave for example.

There doesn't seem to be any clue that the fire is anything to do with the solar panels, other than a throwaway comment from one of the neighbours. It looks more like an explosion inside the house to me. Would be interesting to see the fire service investigation or something authoritative like that.

Of course that hasn't stopped a newspaper that likes to complain about anything 'green or woke' from splashing scaremongering headlines!


The BBC are reporting the fire service said it was actually an electrical fault inside the house but they can't get in to find out exactly what appliance. Could be the hot water cylinder perhaps?
https://www.bbc.co.uk/news/articles/cq8pjxkex4xo


For interest the operating temperature for our inverter is specified up to +60 degC, by coincidence that's the same temperature commonly quoted as where touching a metal item would cause first degree burns. It's hot enough to cook a steak medium-rare. So yes it can feel very warm to the touch (as per the YouTube guy) but still operate happily!


ETA: the ignition temperature to start a fire of paper, fabric, wood shavings etc is around 250 degC so, no, the warm solar inverter is not setting fire to anything when it's just running normally on a hot day. Need to have an arcing/sparking kind of electric fault in a connection to start a fire and that can happen anytime of year.

The same inverters are used in India, middle east, Australia, countries that are seriously hotter than a UK 'heatwave' of 30deg. The UK newspaper and youtube guys are just click-baiting off the fears of their followers.