Posted on 01/22/2007 3:41:50 PM PST by kiriath_jearim
The extraordinary amount of heat seething below Earth's hard rocky crust could help supply the United States with a significant fraction of the electricity it will need in the future, probably at competitive prices and with minimal environmental impact, scientists now claim.
An 18-member panel led by MIT has prepared the first study in some 30 years to take a new look at the largely ignored area of geothermal energy.
Geothermal plants essentially mine heat by using wells at times a mile or more deep. These wells tap into hot rock and connect them with flowing water, producing large amounts of steam and super-hot water that can drive turbines and run electricity generators at the surface.
Unlike conventional power plants that burn coal, natural gas or oil, no fuel is required. And unlike solar power, a geothermal plant draws energy night and day.
Geothermal research was very active in the 1970s and early 1980s. As oil prices declined in the mid-1980s, enthusiasm for alternative energy sources waned and funding for research on geothermal and other renewable energy was greatly reduced, making it difficult for the technology to advance.
"Now that energy concerns have resurfaced, an opportunity exists for the U.S. to pursue the enhanced geothermal system option aggressively to meet long-term national needs," said panel head Jefferson Tester, a chemical engineer at MIT.
Fossil fuels such as coal, oil and natural gas are increasingly expensive and dump carbon dioxide and other pollutants into the atmosphere. Furthermore, oil and gas imports from foreign sources are not necessarily secure in the world's shifting political climate.
(Excerpt) Read more at livescience.com ...
I know of a commercially owned structure which uses well-water (not very deep wells either) warmed heat pumps, instead of air-warmed heat pumps. Since heat pumps work ideally at over 40 degrees, and groundwater is a constant 54 degrees, using water jackets instead of air works admirably--also the units are placed in the cellar, not outside. Of course they also work great for the AC too.
The energy savings for this energy ineffeciently constructed (historic) building with no insulation, amount to hundreds of dollars a month. It took 2 wells though...at a cost of 10,000 a well. Still, in not to long of a time, the system should pay for itself.
Probably in similiar ways to the methods used in the US.
Geothermal Energy Association
http://www.geo-energy.org/information/plants.asp
This would be a tremendous advance - avoiding all the corrosion problems.
"This is typical of the 70s revival. Geo-thermal, wave, wind, solar, electric, co-generation, etc. were all the rage back in the day. Now, 3 decades later, the hippies have come back"
No - back then it was geodesic domes and geo thermal heat pumps - now it is corn stoves.
The Wright brothers also failed the first few attempts.
-zb
Yeah, Earth First.
Exactly how much oil do you think is being burned to spin a turbine?
I've been in most of the base line power plants in the upper midwest and have yet to see anything rated above 50MW burning anything but coal or uranium. Other than natural gas, the only petroleum products I've ever seen burned is kerosene (J4) in GE jet turbine backups. The gas burners' output watts hardly rank as "base line". Its why they're called "peakers".
Seems like these problems would not be a consideration if they used a heat exchanger system where the water, or some other fluid, was circulated through the hot areas to pick up the heat but never actually came in contact with whatever is down there.
I can see where pumping water down there and then collecting the steam, along with all the contaminants, would foul pipes and valves. But a sealed system would not seem to me to have that drawback.
"Does anyone know how they're getting around those problems in Iceland?"
The hot water bubbles to the surface. They don't have to go get it.
You external (metal) casing is always exposed.
The solution is to cement it in, but good luck getting a good squeeze job at the depths in question.
How about "Crackpots in Congress?" Only it isn't a movie.
GE offers the widest range of heavy duty gas turbines available, ranging from 26 to 480 megawatts
Our county just constructed a new school in my area, they are using the under ground wells for heating and cooling.
The system is working very well, saving the tax payers money.
How will congress tax and regulate it?
Can entrepreneur X just do it? Or do they need to make campaign contributions, hold committee hearings, pay for experts with a large staff to study it and issue a report that recommends a new FEC - Federal Earth Commission ...
Or maybe it is a UN issue. Who is to say that a country's boundaries extend that deeply into mother earth?
That's a nice picture on your homepage! Where was it taken?
As, or if, geothermal begins to look viable the oil producers will again reduce prices and "enthusiasm" will again "wane."
Its a picture I found from Glacier National Park in Montana.
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