Andy Hall wrote:
On 2007-12-10 22:00:33 +0000, John Rumm
said:

The carbon footprint stuff is nice in concept but fairly meaningless
in reality. Unless you know the true energy consumption (and the
carbon released during its generation) during the extraction of raw
materials, the production, distribution, installation, and finally
disposal of the system, you can't make any realistic assessment as to
whether you are having a net positive or negative effect.

Another cosy, fluffy thing where people can feel that they are "doing
their bit"


I have solar heating. In winterm,, the windows in the drawing room face
south. We open the curtains and gain about 2-3 degrees temp rise during
the day.

Thats probably at least a kilowatt of input.