geothermal energy

[Stellar Gellar]

i've been a member here for quite some time now, but i haven't encountered any talk about geothermal energy. i don't think it's the same as hydropower, and i've heard it's much more beneficial and efficient in the long run. what do you guys think?

[Rob Beckers]

Hi Stellar,

There are not many true 'geothermal' energy projects out there, and those few are a bit beyond home use. While in The Netherlands last Christmas there was a TV program about geothermal energy, showing a new trend for relatively small businesses to drill the very deep wells required (plus you have to live over a geothermal hotspot, where heat from the earth is not too far down). It seems that for businesses that need large amounts of heat (greenhouse farmers for example) it can make financial sense.

What most people think about as geothermal are heat pumps that use either a ground loop with glycol, or ground water. Strictly speaking those use 'shallow' heat, put in there by the sun (heat traveling from the earth's surface down for storage, where the temperature only very slowly changes so it stays a constant 10C or so). This is not geothermal energy. True geothermal uses the heat deep down in the earth, powered (mostly) by radioactive decay. We've had some discussion about heat pumps in the "green building" and "building materials" forums if memory serves me. They are certainly getting up there in efficiency with the new scroll compressors.

-RoB-

[Joe Blake]

I know in Oz we have many instances of artesian bores bring hot water to the surface, but I don't whether (or how) this energy is being utilised.

http://en.wikipedia.org/wiki/Great_Artesian_Basin

Joe

[Stellar Gellar]

hey thanks for the comprehensive info. i really appreciate it. i was surprised (and proud) when i found out through wikipedia that the philippines comes in second in producing geothermal energy worldwide.

[Paul Bailey]

Here's the linkhttp://www.geo-energy.org/publications/reports.asp

Its the very top Center New Report. Paul

[Rob Beckers]

Thanks for the link Paul! Interesting report.
Notice the hotspot on the map where Yellowstone is located. Of course, where I live it's barely 75C, and for that measly temperature I would have to drill 6 km down. Not going to happen. :sad2:

-RoB-

[Ralph Day]

Lets all hope that no-one goes poking at the potential of Yellowstone with a drill. It's one of the world's potential killers...we're talking cubic kilometers of gasses and ash blanketing North America if it ever blows (again). Survivors would be few and far between...probably the survivalist element if they wern't in the immediate death zone. PBS and Nova can be a frightening thing to watch!

Ralph