dennis@home wrote:


"The Natural Philosopher" wrote in message
...


The problem with geothermal is that as stated the heat flux is only
about 0.1W per square meter. compared with a couple 40-200 W from
insolation.(UK)

so a typical 1-2KW average domestic usage represents about 10-20,000
square meters.of land area that you need to 'rob' of geothermal heat.
sort of football pitch sized.

That's a big football pitch some what larger than the 200 m2 that you
were telling me I needed a few posts ago.


But efficiencies are better, as you can get boiling water a couple of
Km down.

Oh do keep up at the back.. the rate of heat influx is the same ~0.1W m2
so you may be able to extract boiling water for a short period but it
won't last long.
Why do you think there are no geothermal power stations drilled in the
UK if you only need to go down a mere 2km?


because it costs a lot to go down that deep.

Why do you think there *are* geothermal power stations elsewhere where
mines already exist that deep?

we could be using ours, if they werent mothballed for possible re-use.