TPO Solar: Don't.

First, TPO = Third Party Ownership

Not from personal experience, but instead I refer you to this article at Bloomberg:

What Happened When I Bought a House With Solar Panels

Really though, it's a pretty crappy title.  There's nothing physically wrong with solar panels on a house, apart from usually not making financial sense and having a bunch of holes in your roof.  The real problem is the complicated financial schemes some people sign into to get them on that house with no money up front.  "No Money Up Front" = "Trouble."  And afterward, good luck trying to sell that house while it's still under one of these contracts.

Anyway, there's your medium-long weekend read.