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Author Topic: Is geo-thermal really a good clean energy?  (Read 1672 times)

Offline Eric A. Taylor

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Is geo-thermal really a good clean energy?
« on: 29/09/2010 13:17:10 »
I first heard of geo-thermal energy in the early 90's and got really excited that it might be a very good, clean energy source. I did some research on it and was very badly  let down.

Geo-thermal is fairly straightforward. You drill a deep hole in the ground, deep enough so the heat from inside the earth will allow you to boil water pumped through the hole. This works best in places where magma is close to the surface. Seems like a great idea. Nearly unlimited power and no carbon footprint.

Well not quite. Trouble is there's lots of very toxic things down there. When you pump the water down there the hole toxic things are picked up by the water then carried to the surface, where when the water cools, they turn back to solids, mucking up your steam turbines. Not to mention, what are you going to do with all this toxic water?

If you don't believe me take a look at Yellowstone NP. Almost every hydro-thermal vent is surrounded by a soft brittle rock called gyserite. Where trees have been inundated the water is drawn into the tree killing it and preserving the wood. It's really quite dramatic. (I have pictures and will post some here if I can figure out how).

Given these problems, why is geo-thermal still being considered?


 

Offline Geezer

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Is geo-thermal really a good clean energy?
« Reply #1 on: 29/09/2010 21:20:55 »
I happen to know quite a bit about geezerite  :)

Er, well, you don't have to put the mineral laden water into the turbines. You can run it through a heat exchanger to convert much purer water into steam to drive the turbines, but I suppose you still have to watch that the minerals don't clog up the heat exchangers. It's possible they also treat the water that goes through the ground, but I'm not sure about that.

They do seem to be able to make a go of geothermal energy in Iceland and New Zealand, and there are some spots in the US that do too. I seem to remember driving past one somewhere - I think it may have been in the top end of Nevada.

The main thing is the temperature of the geothermal reserve. If it's not hot enough, it does not produce much mechanical energy. There are a lot of places where it's not hot enough to be much good for power generation, but it can be used as a good source for heat pump heating systems.
 

Offline LeeE

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Is geo-thermal really a good clean energy?
« Reply #2 on: 29/09/2010 23:22:38 »
Putting a geothermal plant in the Newberry Crater has been talked about for many years.  It's a shame that the wikipedia article about it is so out of date.

http://en.wikipedia.org/wiki/Newberry_Crater#Geothermal_Power
 

Offline mazirra

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Is geo-thermal really a good clean energy?
« Reply #3 on: 30/09/2010 09:53:12 »
Hi

Here you will find a list of many solar, wind and geothermal energy related articles, including various articles on other forms of renewable energy.

We hope these articles will be of use to you in finding the information you require. If you have any issues with the below publications or would like to suggest changes to the content of these articles, you can provide feedback via the contact us page.

All our publications focus on the environment and renewable energy, including how we can help to improve the quality of the air we breathe, and on a larger global scale, how we can possibly reduce the future effects of global warming.

[Spam removed! This is not the classifieds! Please do not put your company ads here. -Mod.]
« Last Edit: 30/09/2010 11:04:00 by peppercorn »
 

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Is geo-thermal really a good clean energy?
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