We have a semi flex solar panel on top of the van. This is different to a typical rigid solar panel as it can bend with the general curve of the roof. I assume this would also be beneficial on a boat too, but I’ve no experience of that.
To attach a semi flex panel to the roof of your campervan or motorhome you can drill holes and screw it down. However I found this unappealing due to the risk of leaks (which would then get into the insulation underneath… Big mess!).
Instead, I stuck mine to the roof with some double sided tape. Now, this isn’t your average double sided tape… The panel would rip off in no time as you drive away.
3M make a special line of Very High Bond tape (VHB) which is really intense stuff. Furthermore, because of the high temperature that your panel will reach you need the version of 3M’s VHB tape that can deal with high temperatures. I think there are multiple versions of this, but I used 3M VHB Tape GPH-160. Occasionally you can find it on Amazon (try here US: https://amzn.to/2Fe1NQR or here UK: https://amzn.to/3mgK6Ri).
It ordered a 33M role and still have loads left after attaching our 160W panel.
Once this stuff is stuck down it’s almost impossible to move, so you need to get it right first time! This is how I did it:
- I lay the panel where I wanted it, marked that out with pencil on the van roof
- Cut small strips of tape and stuck them all over this area (leaving the top of the tape still covered)
- Made sure the edge at the front of the van had plenty of tape and wouldn’t let air blow underneath the panel
- Checked again with the panel to make sure all the areas would be stuck down appropriately
- Pulled all the covering off the tape to expose the top side
- Put the panel on its long edge, lined it up with the tape and then very gently (sweating a bit!) lowered it onto the tape
- Pressed it down all round
One thing to make sure of is that you don’t make any sealed pockets of air underneath the panel. This would heat up and expand causing problems. Just make sure all air has a way out and you should be fine.