One of the considerations was how much it would get in the way on the roof, so I made a paper mock up of the probable panel and put it in place. A very good thing to do, as it allayed our fears a fair bit on that score. It doesn't look to obtrusive does it?
This is the size and shape of a 95watt Kyocera panel. I'm intending to feed the cables through the mushroom vent from where it will be relatively easy to route it in some conduit across the galley ceiling (which luckily is white) and into the lighting trunking and back to the controller which I will mount near the rear doors from where the cables to the battery will be a shortish run.
As to how to fix it to the roof, to start with I'm going to use magnets. You can now get very powerful cylindrical ones with a hole through so you can insert a stainless steel screw or bolt. The advantage is I don't have to drill holes in the boat roof or use adhesives. So if we change our mind on positioning after a short while, we can do it .
Some of these magnets have ferocious power and come with safety warnings about trapping your fingers. We'll be using relatively modest ones but still powerful enough to make a very firm fixing.
No doubt it will not be as easy as it looks but we'll see.
Meanwhile, today I hand over Herbie to Rick, Marilyn, Tim and Daizee for the weekend. They're going through London to Limehouse and back, so if you see Herbie give them a wave.