This is a property in an adjacent road to us, perhaps with too many PV panels: I took the photograph at just after 3.30pm towards the end of last month, and already the sun is off nearly half of the array. Our decision last year to go down the solar thermal route, rather than have PV, was governed by similar considerations of shading.
12 months having now elapsed since we finished with the plumbing firm that did our work, we can look at what a difference it's made. Not only did we instal three roof panels, but we upgraded the gas boiler and the radiator system. The result? Gas usage is barely more than half what it was before; daytime electricity about two-thirds, and night-time units about three-quarters. Of course, the 2011/12 Winter has been milder, but that's still an appreciable saving, in my book!