Hit by Solar Panels

Scary indeed, & not the first instance of an incident like this. To be honest I think it is a matter of luck that this is not far more common.

It might help if those plastic corners sold for panel fixing to vehicle roofs were banned or at least the sellers of them providing safe info about attaching them to vehicle roofs (as well as advising periodic checks of the mounts integrity!

One of the most highly regarded Australian companies producing a variety of electrical components sells these things & advises

" can be attached using the appropriate type/grade of silicone adhesive "

This in my view is close to criminal. As far as I know there is no silicone adhesive suitable for this purpose, unless the word 'silicone' is used as a generic term for 'goo'. And you see folk advising others to use silicone, and/or stating they have used it themselves.

Another Seller of these plastic corners advises using Marine grade Sikaflex. There are Marine grade adhesives in the Sika range which would be suitable, but the commonly seen 'Sika Marine'on the shelves at retail outlets like Bunnings is not one of them. That one is a sealant & unsafe to use for attaching panels to vehicle roofs. (Contrary to the dangerous advice I have read on most RV forums at some time or another).

Then there is the issue (only anecdotal - no direct experience as I wouldn't use them myself) I have read over the years of these plastic corner mounts deteriorating - UV affected.

I am certain that there are many many RV's out there with dangerously attached solar panels, & my automatic reaction is, to stay well away from an RV on the road which has panels attached as a result.

FWIW I have mounted solar panels on two vehicles & am totally confident in their security. I used aluminium angle which the panels are bolted (not screwed) to, using nyloc nuts.
The aluminium angle is mounted to the vehicle roof, metal to metal (not onto the paint), with the metal of both surfaces lightly roughed up with emery cloth, & then cleaned with isopropyl alcohol before applying a correct thickness bed of the correct Sikaflex adhesive. Sika themselves advise Sika 252 in combination with their specific primer. However I , and many folk I know have used Sika 11Fc for decades, which is a sealant/adhesive, cheaper & easier to use than 252. The panels on the roof of our current vehicle have now been on there for 10 years & over 1000'skms of rough outback roads & tracks & remain as solidly in place as when first fitted - I still check them periodically & I believe that if an attempt were made to lift the car using the panel mounts that the aluminium would let go before the adhesive.

The skin on the top of a van is not secured to the cross members. It is of too light a gauge to hold pop rivets. It is strong enough to carry solar panels in the mounts spread over a large enough an area and the preparation is done well enough. It is advice like that that leads me to say that the installations should be done by caravan service people or other people who have had the required experience attaching other similar things. I don't think the task should be given to the average auto sparkie.

That is extremely bad advice you just offered.

If the roof skin is not secure enough to rivet panels to it then how could it possibly be strong enough to sikaflex them doesn't make sense the same wind force will be hitting them. Maybe combine the both to make sure using strips of alloy angle riveted and sikaflexed to the roof you can make a tapered leading edge for aero to help reduce stress from the wind trying to rip the panels off. And the panels will have a gap to reduce heat when parked up.

roof panels are glued on cars so there are glues available

Batt's it is all tied up with distributed loads. If you spread the load across a large enough area you can attach a fairly large load. Pop-rivets are a point source attachment. They are very easy to pull out of thin gauge metal.

Batts, no insult intended, but your view harks back to earlier times. Using the correct adhesive correctly outperforms rivets any day.

I think we are all in agreement that the panels on vehicle roofs being poorly secured is dangerous though.

I'm not the sort of person that would just rely on whatever adhesve is recommended no matter how good it's suppose to be. I'm a lot more responsible than that and can't for the life of me understand how others can honestly feel good with themselves solely relying on some adhesive that breaks down overtime without also using a 2nd way of helping to secure items like solar panels. I have 2 panels very securely attached to my ute's chequer plate canopy but if I couldn't do the same to a van I would rather go without.

the thing is if you have a late model car it will have panels solely glued on and they do not come off

Not just late model cars Chris. There are plenty of motorhomes & caravans with composite fibreglass 'sandwich' panel construction getting around & have been for more than a decade where the design has no frame & the whole lot is held together by sikaflex or similar adhesive products & no mechanical fasteners. They are stronger & lighter than 'traditionally built' products & have both now stood the test of time & the test of long term usage off road & across the world.

No one disputes that solar panels fixed well onto vehicle roofs are safe, and Batt's expressed preference to remain 'old school' with what he knows is perfectly valid. However his distrust & criticism of modern adhesives looks like Luddism to me.

Yeah Warren,my first instinct was to keep it straight A’s the wire rope safety barrier was on my left pretty close ??