Just diverting back to solar panels in homes, I was chatting today to an ex-colleague in the risk team at BP who is now an independent fire consultant (and used to be the Chief Fire Officer in Norfolk), he said the issues with solar panel fires relate to batteries located in the roof space which are often installed to store power and then deliver it later when needed. Said installations are often (a) placed in a location where the batteries can overheat and (b) the batteries are not enclosed in a suitable enclosure. The result will be fires starting which spread and are difficult to extinguish.
I think I'll ask him to have a look at my daughter's installation!
I enjoy the solar installer Youtube clips where they review other installers' mistakes. No inverter in the attic was an obvious one (and certainly not batteries!) - one I didn't get in my install was to have an isolation switch in the attic for the panels. Makes perfect sense...