These guys are having a laugh that system now is £7000 tops because the feed in tarriff has been reduced,best you forget them and use somebody else,just how much money you get depends on what part of the country you live,if up North you will get less sun so less money also you need the roof to be in the right direction if only a little off you will get less,a good company will check all that out,the bottom line is people installing these systems charged £11,000 a couple of years ago now with the feed in tarriff reduced they fit the same system for £7000,somebody has made a fortune and some companies are still trying too