I knew OCUK would deliver! This is an excellent forum. Seems I can get pretty much any question answered in a matter of hours! Thanks loads for all the replies (and sorry for the initial typo in my thread title)!
To answer the sceptics: as Marin says, solar water heating should have a measurable effect all year round and should provide all your hotwater during summer months (and yes, you do need hotwater in summer: showers, washing up, some washing machines which take a feed from the hotwater tap etc).
I would love to put photovoltaic cells on my roof by they are VERY expensive and less efficient than solar water heating and I'm on a tight budget. Solar heating should easily reach 30% efficiency where as most PV cells are closer to 16% efficient. Not to mention that it would cost many thousands of pounds to cover a roof in PV cells. (I'm on such a tight budget that I'm seriously thinking of making my solar water heating system myself although I'm not sure I'd be eligible for a grant if I do)
I too have been interested in wind power but I've been put off... it seems the consensus is that wind power is pretty futile in London because the wind is far too gusty. Does anyone have an opinion on that? (Looking out my window right now it looks pretty windy! Maybe gusting up to 20mph)
Finally - are there any forums (or news groups) for people who are planning to add alternative energy solutions to their houses? Much as I love OCUK, I find it hard to believe that OCUK is the most appropriate place for discussing this stuff!
