For those who haven't read all the comments:
1. If there is a power cut the panels cut out as well, because if they kept generating the national
grid would still be getting charge going back on to it (remaining live) and would be unsafe to work on. There have been some interesting comments with regard to batteries, but these would not be applicable to free panels as the leasing arrangement states that Home Sun own the panels and all other associated equipment and you are not allowed to fit anything on to the system. (I thought that was the cases, but I just asked Trevor to make sure I had the details right)
If anyone does decide to get panels from Home Sun or is contacting them for a survey, I'd much appreciate the referral fee (for my fund for buying a maypole, or for charity if you prefer), so please do tell them that you heard about it from Judith Proctor.
If you'd rather contact a person (especially if you have any questions) than go through the web site, you can call Trevor - the guy we dealt with, who was helpful and non-pushy - on 07880 567 500. He says he's happy to answer any questions people may have - again, mention my name.