Yeah, that could be it -- unfortunately, the solar company that installed the system went out of business six months ago (the company I contacted is carrying the warranty on the panels but knows nothing else about my system) so unless I pay money to have someone look at it I have no real idea.

But I like that theory -- although where the water was coming from seems somewhat unlikely considering it was on the piping on one of the middle panels (I'm far from an expert here, but I wouldn't think anything like those valves would be installed somewhere arbitrarily in the middle sections but perhaps that's *exactly* where it would be installed).

I'm guessing at some point (assuming all stays well in the immediate future) I'll have occasion to have some repair work done and at that time I'll ask whoever knows about these things what could be the case up there. OTOH, perhaps it truly is a leak that is just waiting to happen again...