Too much condensation on plastic roof over electric panel, should the roof be redone?

I rebuilt a roof on a well house because it was so damn rotten. So I went with corrugated polycarbonate so that it wouldn't rot again. This is Washington where everything rots. An electrician came out today to fix the panel and saying it needs plywood instead because there's too much condensation on the roof. I'd hate to redo it all if there's a simpler solution. I tried to mention I could vent it a lot more since there's really no venting, but he said he doesn't think that would help. What's your thoughts reddit?