You won’t have a problem with solar panels. I have 6 100W panels and 6 sticks of low profile unistrut up there. Thats 200 pounds. It doesn’t even know it’s there.
The unistrut is attached by drilling through the ribs and using carriage bolts from the inside. I used a neoprene-backed washer and sikaflex 505UV sealant. I got the neoprene backed washers and those saddle washers for the unistrut from McMaster Carr