I installed a 200 kilowatt (I think) solar array on a rooftop in Yonkers NY back in the 90's using VHB tape. Half of it came off in a windstorm and landed on the ground downwind. Half wouldn't come off no matter how hard you yanked on it. 

Pressure sensitive adhesive (PSA) tapes have been around for a long time. They can work well, but they are sensitive to surface cleanliness, dryness, application technique, etc.  Also the tapes are used for the frameless "flexible" solar modules which I don't want to use. I don't want to get into why here and start an argument with folks who are using them successfully.  

So, I think I'll stick with mechanical fasteners and framed glass solar modules. I plan to attach at the roof edges (probably to the top of the sidewalls into the aluminum box tubing there) which will both eliminate holes in the roof itself but also will put the fasteners in shear rather than tension which will be much stronger.  

Thanks again though for your suggestion though, I appreciate your taking the time. 

With regards to mounting your solar panels; I spoke to a guy at the North East Rpod rally last month that used 2 sided tape. He told me that 3M makes a product that is specifically designed to mount solar panels. I did a quick web search and found 3M VHB tape is used. You may want to check that out. It saves putting holes in the roof.

I have noticed that on cool mornings our pod, sitting in the driveway, will be covered with condensation, except for the places where the supporting studs are located.  I can see every one of them.

The human eye is incredibly adaptable to varying light levels. You only need about 150-200 lux to read comfortably. Direct sunlight is about 100,000 lux, indirect daylight about 10,000 lux, indirect light on a cloudy day about 1000. That's why even a small skylight can brighten up an interior space so much.

This instead of AC

Ben Herman, if its cooling you're after then short of cutting holes in the roof what I did was buy two of these:

https://www.amazon.com/gp/product/B003SS62PS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I added a 12V cigarette lighter receptacle, a cig lighter wye, and a cig lighter extension and clipped the fans so they are hanging down on the window valances in front of open windows in the sleeping area. Works pretty well. 

If you're after additional light then there isn't much choice other than ceiling holes. At least the roof vents/fantastic fans use standard 14 inch holes and are well designed to avoid leak problems. I wouldn't try to install one in an area of high roof curvature though, that would be much more leak prone. 

If you aren't using your aircon that can be removed and a standard roof vent/fantastic fan installed in that existing 14 inch hole. That wouldn't increase the risk of roof leaks because that hole is already there.

I called FR and they confirmed that the wall top frame members are 1 inch square box tubing that they buy pre-curved. Tubing wall thickness was estimated at 1/16 inch, but I'd sure like to confirm it.

The flat part of the roof is aluminum framing with wood framing overtop.

That video is very helpful, thanks mcarter. The wall upper edges appear to be framed in some type of aluminum shape, hard to tell exactly what. Anyone know what that is and what gauge? Reason I'm asking is that I want to mount my solar modules into those edges rather than the roof itself. 

fred