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Abundant Power from Universal Geothermal Energy
Technology Review (MIT) ^ | August 1, 2006 | By Kevin Bullis

Posted on 08/01/2006 11:15:01 AM PDT by aculeus

An MIT chemical engineer explains why new technologies could finally make "heat mining" practical nearly anywhere on earth.

A section of the geothermal plants north of San Francisco, known as The Geysers. These plants rely on relatively rare geologic formations. MIT professor Jefferson Tester believes geothermal can be much more widespread, by making artificial reservoirs for harvesting the earth’s heat. (Source: National Renewable Energy Laboratory)

The answer to the world's energy needs may have been under our feet all this time, according to Jefferson Tester, professor of chemical engineering at the MIT Laboratory for Energy and the Environment. Tester says heat generated deep within the earth by the decay of naturally occurring isotopes has the potential to supply a tremendous amount of power -- thousands of times more than we now consume each year.

So far, we've been able to harvest only a tiny fraction of geothermal energy resources, taking advantage of places where local geology brings hot water and steam near the surface, such as in Iceland or California, where such phenomena have long been used to produce electricity. But new oil-field stimulation technology, developed for extracting oil from sources such as shale, makes it possible to harvest much more of this energy by allowing engineers to create artificial geothermal reservoirs many kilometers underground.

Tester calls it "universal geothermal" energy because the reservoirs could be located wherever they're needed, such as near power-hungry cities worldwide.

Technology Review spoke with Tester about the potential of universal geothermal energy and what it will take to make it a reality.

Technology Review: How much geothermal energy could be harvested?

Jefferson Tester: The figure for the whole world is on the order of 100 million exojoules or quads [a quad is one quadrillion BTUs]. This is the part that would be useable. We now use worldwide just over 400 exojoules per year. So you do the math, and you know you've got a very big source of energy.

How much of that massive resource base could we usefully extract? Imagine that only a fraction of a percent comes out. It's still big. A tenth of a percent is 100,000 quads. You have access to a tremendous amount of stored energy. And assessment studies have shown that this is thousands of times in excess of the amount of energy we consume per-year in the country. The trick is to get it out of the ground economically and efficiently and to do it in an environmentally sustainable manner. That's what a lot of the field efforts have focused on.

TR: We do use some geothermal today, don't we?

JT: In some cases nature has provided a means for extracting stored thermal energy. We have many good examples. The Geysers field in California is the largest geothermal field in the world -- it's been in production for over 40 years and produces high-quality steam that can readily be converted into electric power, and it's one of the rarities nature-wise in terms of what we have worldwide. In the mineral vernacular they would be regarded as sort of high-grade gold mines.

TR: But haven't people been talking about greater use of geothermal energy for years now? What's changed?

JT: Like many energy technologies, it had a lot of support structure back in the 70s and in the 80s, but our national priorities shifted from energy to other things, and we didn't necessarily invest enough in it at that time to bring it to fruition.

Many [energy] technologies, whether they're renewables or nuclear power or coal or whatever it might be, need to be continually revisited and placed in context with the current state of technology. In this case, our interest in trying to go after hydrocarbons and extract hydrocarbons has developed a lot of technology in subsurface engineering that's useful and makes geothermal worth revisiting.

TR: How do you plan to harvest stored heat from more areas?

JT: What we're trying to do is emulate what nature has provided in these high-grade systems. When we go very deep, [rocks] are crystalline. They're very impermeable. They aren't heat exchangers like we really need. We'd like to create porosity and permeability. [The rock] actually is filled with small fractures, so what you're trying to do is find those weak zones and reopen them. We need to engineer good connectivity between an injection set of wells and a production set of wells, and sweep fluid, in this case, water, over that rock surface so that we extract the thermal energy and bring it up another well.

TR: What technology do you need to open up the rock and harvest the heat?

JT: All the technology that goes into drilling and completing oil and gas production systems, [such as] stimulation of wells, hydraulic fracturing, deep-well completion, and multiple horizontal laterals, could in principle be extended to deep heat mining. Hydraulic methods have been the ones that hold the most promise, where you go into the system and you pressurize the rock -- just water pressure. If you go higher than the confinement stress, you will reopen the small fractures. We're just talking about using a few thousand pounds per square inch pressure -- it's surprising how easy this is to do. This is a technique that's used almost every single day to stimulate oil and gas reservoirs.

TR: What still needs to be done to make artificial reservoirs for geothermal possible?

JT: Like any new technology, there are technical issues. But I don't see any show-stoppers. I think that the evolution of the technology, with 30-plus years of field testing, has been very positive. The basic concept has been demonstrated. We know how to make large reservoirs. We need to connect them better, to stimulate them better than we have in the past using some of these hydraulic methods and diagnostics that are now available to us.

So it's the scale-up to a commercial-sized system that has to be done, making a heat mine that is large enough and productive enough to sustain the economic investment. But we believe that's possible to do based on where we are now with the technology.

TR: You're working on new drilling technology. How does this fit in?

JT: We feel that as part of a long-term view of the possibility of universal heat mining, we should also be thinking about revolutionary methods for cutting through rock and completing wells. Most of the drilling that's done today is made by crushing and grinding our way using very, very hard materials to crush through and grind through minerals in the rock. And it's been very successful. It's evolved tremendously over the past century, and we can do it, certainly, routinely, to 10 kilometers. But it costs a lot. So we're looking for a fundamental way to change the technology that would change the cost-depth relationship, and allow us to drill deeper in a much more cost-effective manner. It would open up the accessibility tremendously.

TR: What are the advantages compared with other renewable sources of energy?

JT: Geothermal has a couple of distinct differences. One, it is very scalable in baseload. Our coal-fired plants produce electricity 24 hours a day, 365 days a year. The nuclear power plants are the same way. Geothermal can meet that, without any need for auxiliary storage or a backup system. Solar would require some sort of storage if you wanted to run it when the sun's not out. And wind can't provide it without any backup at 100 percent reliability, because the typical availability factor of a wind system is about 30 percent or so, whereas the typical availability factor of a geothermal system is about 90 percent or better.

TR: What are some environmental concerns with "heat mining?"

JT: Obviously in any system where you're going underground, you need to think about are you disturbing the natural conditions in the earth that might cause bad things to happen. We have a pretty good history of knowing the effects of extraction. Nevertheless, it has to be monitored carefully and managed carefully.

In some natural systems you have to deal with the emissions -- control of hydrogen sulfide and other gases. Environmental regulations insist on full re-injection of the fluid.

This is not a free lunch, but there's virtually no carbon dioxide, so you're producing baseload electric power without generating any carbon dioxide.

TR: How fast do you think artificial geothermal systems can be developed?

JT: With sufficient financing and a well-characterized field, you can go into existing areas right now and build a plant, getting it operational within a few years. But to get universal heat mining is going to take an investment which won't be quite that quick. It might take 10 or 15 years of investment to get to the point where you have confidence that you can do this in virtually any site that you can go to. Once it gets in place, though, it can be replicated. I think it's very reproducible and expandable. That's the great hope at least.

Copyright Technology Review 2006.


TOPICS: Extended News
KEYWORDS: energy; geothermal
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1 posted on 08/01/2006 11:15:03 AM PDT by aculeus
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To: aculeus

I have never understood how Geothermal energy works. Theoretically, a very hot earth core would radiate heat outward until temperature throughout the crust equalized. What produces the heat? If you drain the core of heat, how is it replenished?


2 posted on 08/01/2006 11:19:14 AM PDT by domenad (In all things, in all ways, at all times, let honor guide me.)
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To: aculeus

here's and Aussie firm working on this:
http://www.geodynamics.com.au/


3 posted on 08/01/2006 11:20:48 AM PDT by Uncledave
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To: aculeus

Very interesting stuff - thanks for the post


4 posted on 08/01/2006 11:20:55 AM PDT by eraser2005
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To: aculeus

Abundant, yes. However, it's going to be very expensive to create such reservoirs in areas where near-surface geothermal sources are not available.


5 posted on 08/01/2006 11:21:04 AM PDT by scooter2
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To: aculeus
I'm not sure about the "anywhere in the world" part,but I've seen geothermal power at work in a city in New Zealand called Rotorua.

Many,if not most,of the buildings in the town are heated by geothermal steam (it's located in an active geothermal area).

The downside is that when you're walking down the street you can get a powerful,and unpleasant,smell of sulfur in the air.

6 posted on 08/01/2006 11:21:05 AM PDT by Gay State Conservative
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To: domenad
Think about emptying the ocean using a thimble.

You are depleting it, but not measurably.
7 posted on 08/01/2006 11:21:08 AM PDT by thackney (life is fragile, handle with prayer)
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To: aculeus
What technology do you need to open up the rock and harvest the heat?

Nukes

8 posted on 08/01/2006 11:22:53 AM PDT by RightWhale (Repeal the law of the excluded middle)
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To: domenad

The earth is still giving off more heat than it gets from the sun. The core won't be cooled off much by thermal mining. It should be good at least as long as the sun itself, that is, another 500 million years.


9 posted on 08/01/2006 11:25:08 AM PDT by RightWhale (Repeal the law of the excluded middle)
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To: RightWhale

The oil industry does this already with water injection and conventional explosives - no need for nukes...


10 posted on 08/01/2006 11:25:41 AM PDT by eraser2005
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To: aculeus
I don't think the Geyser's is the largest area of Geothermal production in the USA. I believe that honor would go to the Imperial Valley.

Geothermal Energy is not inexpensive due to the corrosiveness and abrasiveness of the fluid and it's effect on the equipment needed to convert this source to energy. The Geothermal Brine pumps for example are made primarily by only one company in the USA (Johnston Pumps), as such the costs are not onbly high due to materials, but unusually high due to higher then normal margins. Others have tried, but with limited success (Flowserve, Goulds, Floway).

Geothermal sounds like a good idea, but it is far more difficult then this article implies.

11 posted on 08/01/2006 11:27:04 AM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: scooter2

That's the problem. Whatever is done will take building of infrastructure and even if the energy is free the infrastructure is not. Same problem as solar cells and wind power.


12 posted on 08/01/2006 11:27:06 AM PDT by RightWhale (Repeal the law of the excluded middle)
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To: domenad
Theoretically, a very hot earth core would radiate heat outward until temperature throughout the crust equalized.

I am not a geologist, so take this with a grain of salt.

Yes, the earth is cooling down, However, the process is cosmically slow, and delayed by mitigating factors such as the decay of radiactive elements in the crust and tidal convection from the Moon's gravitational field. If we had a smaller planet (that cools faster) without a significant moon, our planet would be a cold, lifeless rock (like Mars).

13 posted on 08/01/2006 11:27:29 AM PDT by Fudd
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To: Uncledave

I'm in the renewable energy business. I think I'll start a Renewable Energy Ping list.

Who wants on?


14 posted on 08/01/2006 11:27:29 AM PDT by Uncledave
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To: scooter2

It doesn't seem like you would need a natural geothermal source like a geyser (think Iceland or Yellowstone)...

Heck, you can get a geothermal heat pump in the middle of Ohio that is enormously efficient. While you get about 93% efficiency out of a gas furnace, you can get 300+% efficiency out of a geothermal heat pump - all that is doing is extracting heat energy from the earth. That's not that unlike what this is proposing. Just think of an open loop system rather than closed loop, and on a MUCH bigger scale...


15 posted on 08/01/2006 11:28:35 AM PDT by eraser2005
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To: aculeus

We put in a geothermal system (four 200 foot wells under our driveway) when we built our new house five years ago. The AC is essentially free.


16 posted on 08/01/2006 11:29:20 AM PDT by Eric in the Ozarks (BTUs are my Beat.)
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To: aculeus
Don't want to inject fluids under pressure near earthquake zones:
Earthquake Studies -- Triggering quakes with waste

BTW, President Bush installed a geothermal heat pump at his new ranch house in Crawford; however, the pipes are only 300 feet deep, not anywhere near the depth proposed here, and use naturally occurring constant temperature groundwater for heat exchange.

17 posted on 08/01/2006 11:32:23 AM PDT by CedarDave (French report: Landis fails drug test. But, outside of France, men naturally produce testosterone)
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To: domenad
If you drain the core of heat, how is it replenished?

Radioactive decay. This has been understood for nearly a hundred years.

18 posted on 08/01/2006 11:32:53 AM PDT by js1138 (Well I say there are some things we don't want to know! Important things!")
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To: domenad

The average geothermal gradient of the earth is 25°C/km in depth. This means that anywhere that you drill on earth over 4000 meters depth the temperature is above the boiling point of water. You drill to the proper depth, pump water down and collect the steam and recover energy from the heat.


19 posted on 08/01/2006 11:35:00 AM PDT by Species8472
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To: domenad
What produces the heat? If you drain the core of heat, how is it replenished?

The heat is actually caused by - as the article says - "naturally occurring" radioactive materials. Basically, it's an underground nuclear reactor used to heat water to make steam.

And you don't replenish it, but you probably don't have to worry about depleting it, either, since you're not really changing the amount of radioactive decay, just taking advantage of it.

The problem is money. The 'expert' makes light of the fact that there are a few engineering issues to resolve, and I don't doubt the technology is there to do what he wants. But the cost of establishing and maintaining the reservoirs (and the pumping, etc.) is not small. Would this be economically competitive with above-ground nuclear reactors to provide the same heat? I'd like to see the numbers.

Of course, we're nationally stupid on nuclear reactors - paranoid far beyond any rational risk assessment. So on one hand, you might think it would be easier to use a naturally occuring underground nuclear reactor instead. But the first time there's a tiny little earthquake somewhere that someone blames on the drilling, or the pressure, or whatever . . .

It's not clear to me that the socialists who live for the power of restricting other people's choices will ever allow such a 'risky scheme.'
20 posted on 08/01/2006 11:35:46 AM PDT by Gorjus
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To: aculeus
Imagine that only a fraction of a percent comes out. It's still big.

Imagine if I could convince "only a fraction of a percent" of the people on earth to give me $10.......I'd be rich!!!!!

21 posted on 08/01/2006 11:36:16 AM PDT by Onelifetogive (* Sarcasm tag ALWAYS required. For some Freepers, sarcasm can NEVER be obvious enough.)
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To: domenad
I have never understood how Geothermal energy works. Theoretically, a very hot earth core would radiate heat outward until temperature throughout the crust equalized. What produces the heat? If you drain the core of heat, how is it replenished?

Its a nuclear reaction, pretty much self-sustaining and on a the human scale, limitless. But.

This guy is flat out dishonest.
Yes, the heat is there and it's almost limitless but...

He completely ignores the problems associated with its extraction, which have not been solved. I have lived all my life in the area close to the guysers, and the production has been scaled back dramatically since the trial began 30-40 years ago.

The problem is similar to oil shale extraction. The process is easy enough. Dealing with the byproducts is not.
Heavy concentrations of minerals in the process render all the equipment useless in a very short time. Treating the mineral deposits and neutralizing them renders the resulting energy uneconomical; when factoring in the total cost of extraction, it is still economically not viable today.

The problem is analagous to the ICC building at Georgetown University, with a gigantic roof covered with solar cells which had great promise. Until the cost of maintenance and keeping the cells clean for peak efficiency was factored in. It is now just a feel-good white elephant.

There is a fundamental dishonesty with subsidized energy production.

22 posted on 08/01/2006 11:36:20 AM PDT by Publius6961 (overwhelming force behaving underwhelmingly is a waste.)
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To: domenad

Consider that a very large object like earth has a huge volume compared to surface area - as explained by this page:

http://www.tiem.utk.edu/~gross/bioed/bealsmodules/area_volume.html

Since heat can only escape via the surface, most of the heat generated by radioactive decay is trapped inside.

You couldn't drain the core of heat no matter how you tried - The huge amounts of heat we could drill to are a mere onion skin on the earth.


23 posted on 08/01/2006 11:37:12 AM PDT by ko_kyi
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To: domenad
One company, Ormat an Israeli company with offices in Reno, Nevada, has some information on Geothermal. They are one of the world's leaders in the designing and construction of these type of plants. To give you an idea of what is required, here is a picture of one small plant:

In the middle of that small picture is a double shafted motor or generator, probably about 700-1000 HP, connected to what are either a pump and a turbine or possibly two turbines. That equipment represents well over a million in capitol costs alone.

24 posted on 08/01/2006 11:38:37 AM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: CedarDave

The antifreeze liquid comes out of the ground at 59 F.


25 posted on 08/01/2006 11:39:34 AM PDT by Eric in the Ozarks (BTUs are my Beat.)
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To: Publius6961
which have not been solved

Go to the website linked above in my post and educate yourself a bit. The problems you refer to have been solved and are used on a daily basis.

The Geysers has reduced capacity because the geothermal field has been depleted to the point of no longer being economically viable as it once was.

26 posted on 08/01/2006 11:43:14 AM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: All

27 posted on 08/01/2006 11:45:18 AM PDT by WakeUpAndVote (Got towel?)
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To: domenad

The heat is produced by radioactivity within the earth. It's a small amount of radioactivity per cubic inch of interior, but there are a whole lot of cubic inches of material within the earth. The outer layer of the earth acts like a super insulator. The "R" value of the earth is not too good. It's only about R=1 per inch of thickness, compared with R=3 or 4 per inch for a good ceiling insulation. However, again, there are a whole lot of inches of insulation in several miles thickness of earth surface layers. So, the heat from the radioactivity is contained within the earth because of this very thick insulation layer on the surface. The amount of heat generated is large compared with the mount that would be used up with any geothermal devices, so it should last indefinitely.


28 posted on 08/01/2006 11:47:17 AM PDT by norwaypinesavage
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To: Publius6961
I said: The problems you refer to have been solved and are used on a daily basis. Correction:

Many of the problems you refer to have been solved and Geothermal Energy is succesfully used on a daily basis.

29 posted on 08/01/2006 11:50:18 AM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: domenad

Radiation, pressure, and friction.


30 posted on 08/01/2006 11:53:51 AM PDT by Lunatic Fringe (Man Law: You Poke It, You Own It)
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To: aculeus
That's all we need, more Global Warming.
31 posted on 08/01/2006 11:54:48 AM PDT by SmithL (The fact that they can't find Hoffa is proof that he never existed.)
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To: scooter2
Let California live off of geothermal energy. That would reduce the national consumption by about 20% right there and reduce the price of everything else. But, being California, if there is a solution to some problem they will find a way to screw it up, over-regulate it or simply ban it because it causes some other problem (like smell, or heat, or pollution, or noise). Just watch. Its one of the only constants in the universe - the ability of the State of California to foil any solution to any problem.

Nevada is also a huge source for geo-thermal energy in the areas which are entirely owned by the Federal Government and used as a buffer between civilization and the secret air force base which doesn't exist a couple hours north-northwest of Las Vegas.

32 posted on 08/01/2006 12:06:24 PM PDT by bpjam (Remember our fallen Marines from Beirut. Hezbollah deserves no peace.)
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To: Eric in the Ozarks
"We put in a geothermal system (four 200 foot wells under our driveway) ... The AC is essentially free."

Eric, I'm assuming AC means Air Conditioning.

In areas where freezing or snow occurs, a few loops under the driveway to bring the Earth's latent heat up to melt the snow would also be welcome.

I wonder if anyone has tried to put together a low-grade energy generation system utilizing a solar collector for the heat, and a geothermal loop for the cooling? While it would be somewhat weather dependent, the investment costs seem affordable enough to make it worth while for a small plant. Some heat and cooling would be secondary benefits of such a system.

Or to look at it another way, keeping your house cool in the Summertime, and your driveway free of snow and ice in the Wintertime, would be the primary benefits, and a steady stream of low-wattage energy for lights and the refrigerator would be secondary benefits.

33 posted on 08/01/2006 12:11:40 PM PDT by NicknamedBob (Everybody always looks here for some really incredible insight, and they always find this stuff.)
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To: Michael.SF.
"Many of the problems you refer to have been solved and Geothermal Energy is succesfully used on a daily basis."

In a very limited area, where it happens to be both readily accessible and near population centers, which set of special conditions is exceedingly rare.

But the "universal geothermal energy" proposed here is sheer crackpottery.

34 posted on 08/01/2006 12:12:12 PM PDT by Wonder Warthog (The Hog of Steel-NRA)
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To: domenad

Internal heating within the Earth comes from the gravity compression from formation of the planet plus radioactive decay of Potassium, Uranium, and Thorium. It will continue for many millenia. More info here: http://www.sciencedaily.com/releases/2003/12/031215072752.htm


35 posted on 08/01/2006 12:13:24 PM PDT by MainFrame65
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To: NicknamedBob

We do get snow in mid-Missouri and you're correct. The snow melts on the cement driveway, courtesy of this system. Check it out at www.waterfurnace.com.


36 posted on 08/01/2006 12:14:38 PM PDT by Eric in the Ozarks (BTUs are my Beat.)
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To: Uncledave
I think I'll start a Renewable Energy Ping list.

Put me on. I'm very interested.

37 posted on 08/01/2006 12:14:55 PM PDT by Dementon (You're unique! Just like everyone else!)
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To: MainFrame65

That was very interesting, thank you!


38 posted on 08/01/2006 12:17:50 PM PDT by domenad (In all things, in all ways, at all times, let honor guide me.)
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To: SmithL
"That's all we need, more Global Warming."

No, actually, it's Global Cooling.

That part of the Globe is already Hot as ... well let's just say it's hot.

39 posted on 08/01/2006 12:18:35 PM PDT by NicknamedBob (Everybody always looks here for some really incredible insight, and they always find this stuff.)
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To: Uncledave; Dementon; Eric in the Ozarks
"I think I'll start a Renewable Energy Ping list."

Geothermal Energy is not renewable. It's simply inexhaustible.

But ... at least there is that -- "no exhaust."

40 posted on 08/01/2006 12:23:12 PM PDT by NicknamedBob (Everybody always looks here for some really incredible insight, and they always find this stuff.)
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To: aculeus; All
Cool- here's an old post of mine:

Geothermal- Promising Power, or dead-end dillema?

41 posted on 08/01/2006 12:26:35 PM PDT by backhoe (A Nuke for every Kook- what a Clinton "legacy...")
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To: Michael.SF.

Are you referring to fluids in large scale geothermal projects?

The small scale home systems often use the same basic type of fluid you use in your car's radiator. That fluid is recyclable and actually has rust inhibitors.... there's no reason to use brine on small scales....


42 posted on 08/01/2006 12:40:27 PM PDT by eraser2005
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To: Uncledave

If you form one, count me in... :)


43 posted on 08/01/2006 12:41:28 PM PDT by eraser2005
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To: aculeus
A few years back when We were visiting Cali, I saw 'The Geysers' on a map and thought they would be cool to see. After driving 30 or 40 miles, We pulled up to a power plant, looked at each other and began to laugh. Duped Again!
44 posted on 08/01/2006 12:41:45 PM PDT by wolfcreek (You can spit in our tacos and you can rape our dogs but, you can't take away our freedom!)
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To: Wonder Warthog
In a very limited area, where it happens to be both readily accessible and near population centers, which set of special conditions is exceedingly rare.

Not really. Consider: Coso Geothermal, near Mammoth, Imperial Valley, Steamboat, Nevada.

Proximity to population centers is relative to how big of a plant you are building. Plus they can be tied into the grid.

But the "universal geothermal energy" proposed here is sheer crackpottery.

True. At best it is one of many alternative sources that will fill a limited need.

45 posted on 08/01/2006 12:45:19 PM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: NicknamedBob

I think a solar collector for the heat, while nice, is a bit of a waste if you have a geothermal system to begin with.

In the summer you get A/C dirt cheap and you get free hot water (using waste heat off the system). In the winter your heat is dirt cheap but you may not get enough hot water free - only then and when the A/C or heat isn't on would a solar collector provide much use...


46 posted on 08/01/2006 12:46:01 PM PDT by eraser2005
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To: eraser2005
Are you referring to fluids in large scale geothermal projects?

Yes. The article cites the Geysers as an example. That is one of the types of plant I am referring to.

47 posted on 08/01/2006 12:47:20 PM PDT by Michael.SF. (The problem with socialism is that eventually you run out of other peoples money -- M. Thatcher)
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To: NicknamedBob
As we were planning our Missouri retirement house, we looked at several high-tech heating/cooling systems and even a solar electric (off the grid) system. We settled on the Waterfurnace because the company had a good track record and we got to interview others in this area who used our installer. A bonus is that the unit also produces heat for the thermal floor in the lower level which we covered with tile.
I don't think this system would work very well in a northern climate like Minnesota but since our heating demands are moderate, it manages our needs without constantly running (like our gas furnace did in the Twin Cities.) A good amount of blown-in cellulose insulation and high quality Andersen windows have made this place very comfortable.
48 posted on 08/01/2006 12:48:49 PM PDT by Eric in the Ozarks (BTUs are my Beat.)
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To: Eric in the Ozarks; NicknamedBob

Actually, a relative has one up there....

They work quite well in northern climates. You just need more feet of ground loop for a higher tonnage system.

Some areas also have incentives for installation. If I lived about 20 miles further out into the country, the electrical co-op there will pay for the excavation for a ground loop system to be installed. Not only will they pay for the excavation, but they will give reduced electric rates ("We also have a reduced kWh rate of 1¢ from 1001-2000 kWhs each month") and offer 5% fixed rate loans for remaining installation costs....


49 posted on 08/01/2006 12:57:10 PM PDT by eraser2005
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To: eraser2005

Whatever your source of energy for the hot water, a solar heat collector will save energy by acting as a pre-heater for the water, especially in the Wintertime.

The additional cost is marginal, and the collector can house and protect the pumps of the system.

In fact, on mild cool days, distributing the aolar heat collected could mean that compressors may not even need to run.


50 posted on 08/01/2006 1:01:28 PM PDT by NicknamedBob (Everybody always looks here for some really incredible insight, and they always find this stuff.)
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