Anyone got useful experience or recommendations for links / books
reading on _very_ low capital cost solar heating for space-heating of
workshops? I'm looking at the real "Scrapyard Challenge" end of the
problem, with almost everything being built from recycled radiators
etc. The intended result is to raise the Winter temperature of an
otherwise unheated non-commercial workshop to "habitable" (for hairy-
arsed chippies wearing check lumberjack shirts).

Capital costs should be lower than installing other sorts of heating
(i.e. not much), because not much is going to happen otherwise.

Performance should be sufficient to avoid one's brew freezing over.
I'm not aiming for living room comfort, or for hot water supply, here.
A few (?) degrees would count as success.

Areas are about 1,000 sq ft of workshop and a 12' wide roof to sit it
on (the ridge faces South, so the panel would sit above this, against
a South-facing wall). If that's impractical, it might still be useful
to heat a 12' square area of the workshop alone.

Any advice on building a simulation model (probably Excel, nothing
clever) ?