On Sun, 6 Apr 2008 16:33:18 +0100, K wrote:

I was thinking about a smallish heated propagator. Are there any such
things available that run on solar power or are otherwise
environmentally neutral?

It's a difficult question, isn't it? The amount of electricity they use
is small,

True but to get that amount of power from a photovoltaic panel will need a
rather large one which uses a lot expensive, in energy terms, silicon. Not
to mention it will only generate significant power in sunlight when you
probably don't need it to keep you plants warm. So you'll have to store
for use later it in batteries, more resources and energy to manufacture...

What might be possible is a thermal store type system that I've seen
mentioned in here before for keeping greenhouses warmer over night. Large
amount of water in tanks under the benches with a gravity circulation
system through some form of thermal solar panel.

TBH just get a mains powered heated propagator and if you are worried
about the green issues turn your microwave off at the plug when not
actually using it. The power balance will be more or less even.

--
Cheers
Dave.