When we first became interested in self-sufficiency, people were beginning to experiment with all manner of solar heat collectors - made from old central heating radiators, black plastic tubes, rubber inner tubes, and so on. One system I remember was amazingly simple: water trickled down over a glass-covered galvanized steel roof into a trough and then on into a tank in the cellar, where it was used for hot water and space heating. This system did not look very pretty, and it was a huge free-standing structure almost as big as the side of a house, but for all that it was amazingly efficient, with cold water going in at the top end and too-hot-to-touch water coming out at the other. There was another system where black plastic was wound round and round a massive cylindrical house-high water tank. Just as before, cold water went in at one end and came out hot at the other.
Now we have got to the happy state where commercially built solar collectors are not only available at a very reasonable cost - and the costs are coming down all the time - but moreover they are efficient, sophisticated and generally good, well-designed items. If you want to cut energy costs, and are looking for a simple tried and tested method, then solar collectors are a good option.
All that said we have fitted a thermosyphon vacuum-tube system, or more precisely we have fitted a MICROSOLAR system. Currently this system is so far ahead of other apparently similar systems that it is vital that you are able to tell it apart from its various look-alike clones. The difference is not so much the appearance - because there are superficial similarities - but rather in the technical details. For example, while lots of vacuum solar water heaters of this type look outwardly much the same - they have an array of glass tubes topped by a large cylindrical water tank - the genuine Microsolar system has a patented coaxial multi-valve arrangement that ensures that there is no premature mixing of hot and cold water within the tubes, no overheating, no loss of efficiency on cloudy days, and no extremes when it comes to the range of set-up angles. A genuine Microsolar system will work efficiently at a whole range of inclinations - from 90 degrees right down to 5 degrees to the horizontal. What this means is that this system can be mounted on just about anything from a vertical wall through to a flat roof.
Enough to say that our Microsolar set up has been chugging away very nicely for the last year... its beautiful!