Question Downside of using large 400+w solar panels

[Joe Hogan]

There are folks that have installed high quality commercial grade solar panels on RVs.
What is the downside of using these panels vs ones designed for mobile applications?
Other than size, not sure how they survive vibration and stresses of roof mounting on a RV?

 

[Neal]

I have 180's on my roof (10) and I inspect them often as they are held down with 3M VRB adhesive which scares me, but they haven't budged and I haven't found one in the toad windshield yet. Yes, these machines flex as we all know, enough to span the width of a solar panel and cause an issue? Doubt it, but also the fact it's on an adhesive connection may give it some flex, not sure. I've also had mine endure a significant hail storm without damage, so they are pretty durable. I'd be more concerned about the adhesive panels vs. the residential types.

 

[Rich W.]

There is no downside to residential panels and another upside is that higher voltage means you can use smaller ga wire. I abandoned the 6ga factory “solar ready” stuff and used standard 14ga solar panel installation wire. I have 5 315w ~39v LG residential panels on mine and I run them in two strings into two Victron 150v 35a controllers, but there are many options for that. I used these panels because I had them from a previous coach where I had two strings or three for 1890 watts but I could only fit five panels on this coach. 12v panels make for a simple system but I think we’ve all moved far beyond simple anyway. 400w panels might be a little big but with your roof configuration you could make a rack to mount the panels above other penetration which provides even more options.