"NickW" wrote in message
om...
Hi tech stuff is all very nice but have you checked on the price of a
suntracker lately? These types of system often don't pay you back for
maybe 20 years or so.

R&D is still ongoing and the prices will drop accordingly when packaged
solutions are available.

There's a lot that can be done with
simple materials. You might
achieve a collector efficiency of only
60% compared to maybe 80% of a
vacuum tube collector

In this case use more collectors.

or a suntracker but if it costs 1/10th the price
then it could be worth it.

Sun trackers get 3 times the suns energy than flat plate collectors. So
much so they are powering Stirling engines.

This is a good link:

http://www.ece.vill.edu/~nick/

The solar closet is a simple and cheap 'heat battery' to buffer the
avialable solar energy so it last overnight and maybe even over
several overcast days.

Having said all this, I've done some checking and active solar space
heating is considered not to be viable in the UK since it is usually
overcast in winter time... ah well.

You will be surprised at the amount of winter sun the UK gets. It varies
from area to area too: Scotland is different to Cornwall.

Active solar in the UK is viable. The solar closet can be an air heater
inside a conservatory facing south.

The best setup in the UK is firstly superinsulation and elimination of cold
bridges. This is essential. Porches on all outside doors acting as air
locks should also be fitted. A whole south facing roof can be made into a
solar collector storing heat in a large thermal store. The large surface
area means it will efficient enough to gather enough hot water. Then use
"very low" temperature underfloor heating. The reason for low temp is that
in winter the store may not have water stored at a high temp, but hot enough
for low temp underfloor heating. Also have passive solar aspects of
windows, correctly sized roof overhangs for summer shading, deciduous trees,
etc.



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