[LINK] Enhanced geothermal electricity

[Bernard Robertson-Dunn]

Being pedantic, it's not a "completely closed system" that would make it 
a perpetual motion machine.

It's a "closed physical system", or at least, approximately, depending 
on the consequences of heat loss in the rock (shrinkage, cracking, phase 
changes e.g gases liquify, liquids solidify etc., chemical reactions 
that occur at lower temperatures).

There's no such thing as free energy. It all comes at a cost.

On 2/05/2013 2:02 PM, stephen at melbpc.org.au wrote:
> A pleasing announcement. At its best, geothermal power generation uses no
> coal, oil, earth-movement etc to generate electricity. An EGS is a closed
> system producing electricity with no input required. They simply drill two
> holes into bedrock, then create/extend a fracture-cavity 'ball' in the hot
> rocks. They pump water down one hole and up it comes out the other one hot
> enough to generate electricity. Optimally, it's a completely closed system.
>
> Of interest, Geodynamics received half of their start-up capital from ANU.
> They're already the star of the Wikipedia EGS world chart. Now they shine.
>   
>   http://en.wikipedia.org/wiki/Enhanced_geothermal_system
>
-- 

Regards
brd

Bernard Robertson-Dunn
Sydney Australia
email: brd at iimetro.com.au
web:   www.drbrd.com
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