Can't comment on the more modern systems, but we inherited some older style solar panels on our house (the ones which have water running through pipes over reflective panels).
1. They weren't very effective (only really hot water when the sun was blazing), but I understand newer systems are much more effective
2. They were hideous and completely spoiled the rear elevation of a lovely Queen Anne building...how they were ever allowed is beyond me
3. Ours were installed on a slate roof...badly. We experienced leaks around the point where the pipework entered the roof void and eventually some slates cracked behind the panels (but didn't become apparent until the damp appeared on the ceiling)
So we applied for permission to remove and it was granted. Not very green I know, but the biggest single impact on the entire exterior look of the house we have acheived.
My parents had some installed back in 1977 and they worked great all summer and reasonably well during the winter. As far as I recall they were always producing some warm water if not hot. They were still working in the early 1990's when they left that house.
Only required one new pump during that time, but that was a pain to source as the company that had fitted them were no longer in business.
Not a listed or any other type of special building though, just a normal estate semi, but thought I'd mention it as they were just two black looking panels stuck on a roof, not hideous looking and very effective.
That's the one pictured in the posts above... but that was quite a while before we were supposed to have some sort of heritage protection. Round here it's only when it suits Tynedale...