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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.
Carbon dioxide captured from power plants could make geothermal energy more practical.
Guest (GGeorge)
I didn't see this mentioned in the article, but a primary method being considered to increse the surface area by creating more fractures is to use an underground nuclear explosion. On the French web site (link provided by B. van Lew) they describe this as "Enlarge its permeability through massive stimulation".
Other resources:
http://www.llnl.gov/str/October02/October50th.html
http://www.osti.gov/opennet/reports/plowshar.pdf
Guest (Em)
This underground rock fracturing will work 'fine' in connection with the CO2 storage from coal plants, eh?
Guest (dmm)
You'd have to be careful not to ignite a coal seam. Coal seam fires release massive amounts of CO2, are all but impossible to put out, and last a LONG time.
Guest (vcragain)
as always - how do we make this happen- engineers and researchers love to create
the way and means to do new things and solve our problems- but we wont see anything happen unless there is profit to be made - UNLESS we have that
"major project" concept by the government - this is the worst side of our capitalist system - show them the money or nothing happens !!
I have been feeling for so long that we need a new 'energy-focused' party - who will make those big decisions that need to ne made - maybe they will be painful
but we can take it if we know it is
for the future !!
AL please run for president next time !!
vcragain
Guest (Al)
so lets restate that, shall we?
Engineers and researchers can conceive of many solutions, but they won't be implemented unless they are profitable, and they won't be profitable unless they are ... cost effective?
Damn that capitalist obsession with the efficient deployment of capital - what are they trying to do, raise everyones living standards?
And you wonder why Al couldn't win his own state, never mind an election as the incumbant-heir-apparent to a moderately popular president ...
That said, it was an interesting article and geothermal seems to hold significant promise.
The oil business get soo many incentives to make them profitable it is not imaginable. Check it out for your self. How is it that every other industrialized country in the world is developing DHM? Not chance the technology was proven in the 70's/80's, 90's, even the Oil and Gas Journal declared it successful, the profit comes as the technology is used. Microwave oven's weren't profitable in the 50's
''Engineers and researchers can conceive of many solutions, but they won't be implemented unless they are profitable, and they won't be profitable unless they are ... cost effective?
Damn that capitalist obsession with the efficient deployment of capital - what are they trying to do, raise everyones living standards?''
Since when did capitalism become humanist? The only way capitalism inmproves peoples living conditions if it a) can make a buck off of doing it or b) the government makes them. Capitalism is anything but altruistic by nature, actually quite the opposite.
Very few energy industries would exist without government / taxpayer backing. Nice dreamy capitalistic idealism though.
Guest (keith)
while its necessary to look at the many different cost of different technologies government subsidies of technology is not free and if allocated indiscriminately can suck the life blood from an economy leaving it anemic with out a return on investment, and every one ends up the worse off. the most effecent system is a balance of government and industry with a healthy dose of show me the return on investment and its not always in $$
Guest (SteveB)
Wouldn't this essentially bring core heat to the surface where it would eventually be radiated away? If done enough, might we not cool the core to the point of solidification? What might be the environmental consequence of that?
Guest (Keith)
Concerning potential of cooling earth's core.
The earth already radiates away more heat than it receives from the sun, because of the natural decay of radioactive elements. Taping into crust will cool some of the rocks surrounding it which might pose a problem in its self. The Long term and extensive geothermal use at most will only lower the amount of heat reaching the surface of the earth while heat is continually generated inside the earth from natural the decay of radioactive elements.
Don't worry the Earth's core wont go cold.
Guest (Joe)
The magnetic field around the earth would collapse and the planet would be bombarded with high speed charged particles which would eventually strip away the atmosphere,
Guest (Matt)
True, it will cool the earth, but...
It would take a REALLY, REALLY Long time to make a difference.
Guest (OverMatt)
Funny, they thought the same thing about cars...
When you scale it up, a lot of the effects of pretty much anything become huge when a large portion of the total Earth population is using them :) . Think cars!
Guest (gummih)
In Iceland 17% of all electricity is generated from geothermal energy.
Further info here: http://en.wikipedia.org/wiki/Geothermal_power_in_Iceland
There are also active projects for new types of geothermal plants. Drilling closer to magma chambers than ever before: http://news.bbc.co.uk/2/hi/science/nature/4846574.stm
Guest (Cato)
Does anyone on this board know a reliable source of information for learning more about home geothermal systems? I'm in Pennsylvania and am interested in learning about the reliability, performance, and cost effectiveness of the current state of the art of these systems for my own house in this latitude.
Guest (the myrte)
try the geo-heat center at oregon institute of tech:
http://geoheat.oit.edu/
Guest (Rolo Tomasi)
I think going kilos deep into the earth is beyond your average home budget. I'm waiting for the home fusion generator. Maybe a long wait.
Guest (Kent Beuchert)
They are offered by several companies, Carrier being one. They are approximately 60% to 80% more efficient than external air exchange systems. They are also somewhat more reliable, as they operate inside the house and avoid
wearing effects of the environment.
I would like to refer to this topic as Distributed Geothermal energy for heating and cooling homes. The ground source heat pump(GSHP)is a good way of distributing geothermal energy to homes.
Geothermal energy is available just six feet below the earth surface. At this depth, the temperature range between 50F to 60F during all four seasons of the year. Vertical ground loops and horizontal ground loops can make excellent heat source and heat sinks for air source heat pump--thus increasing the coefficient of performance by 40% to 60%. The idea here is to keep the good operating outdoor coils, but adapt a heat exchanger to the coils to take advantage ground loop heat sink and heat source However, research is needed to adapt the ground loops thermally to the existing air-source heat pumps. Often during the winter heating season, heat pumps struggle to gather heat from 20F outside air and deliver it to the interior of the house at 70F. During the summer heating season, the heat pumps struggle to maintain the interior at 75F by removing heat from the house to a 90F outside source.
Up to a 70% savings on heating,cooling, and hot water cost can be achieved, by using ground loops to extract (source) heat from the earth and to reject (sink) heat to the earth.
You can read more about the benefits and cost justification of Ground Source Heat pumps (GSHP) by visiting my website
http://sites.google.com/site/cdlovettdocuments/home/document-list-2/geothermal-summary
The following is short introduction to my paper.
Geothermal heating and cooling systems have substantially more benefits than other types of heating and cooling systems. It provides energy savings that range from 25 % up to 72 % compared with electric resistance heating. Energy savings compared to the conventional air-source heat pumps is about 50 %. Buildings use 76 % of the electricity generated in the U.S. and emits 48% of the greenhouse gases. Geothermal is a green energy technology because it uses less energy and reduces the power generating demand on utility companies. It is quieter, low maintenance and it has a longer service life. The economic justifications for initial installation cost range from compelling for a pay-back period of 9 years, under the assumption of a 30 % federal energy tax credit to a questionable 16 year pay-back time, assuming no tax credits and no escalation of energy cost. The benefits of geothermal systems can be more fully appreciated, if the operation of an air-source heat pump is compared with the operations of a geothermal heat pump.
Guest (Mike)
Instead of using Geothermal energy to drive a steam generator, can the system use a gas or liquid with lower boiling points so the holes we dig don't have to be so deep? If there's enough thermal difference in the Ocean to drive a generator like this, why not Geo-power?
Guest (Millard)
Home Geothermal refers to the use of the earth about four feet below the surface as a heat sink for air conditioning systems and as a source of heat for electric heat pumps. It's another way to raise the efficiency of heat pumps. It has no practical relation to geothermal energy discussed in this article.
Guest (Ralph Bassfeld)
I'd like to draw your attention to advancements in geothermal energy generation for heating/cooling and electricity generation which may interest your readers.
These advancements allow for higher energy output from geothermal wells than existing closed-loop systems and carry less risk and less costs than Hot-Dry-Rock technologies.
The "holy grail" of geothermal energy generation is baseload power generation at economically viable costs and in any location in the world.
I strongly believe we are very close to succeeding in this endeavor. I invite you to visit our website http://www.bassfeld.eu for a short overview of the technologies involved in a document entitled "Geothermal Power Generation". The website is presently geared more to electricity generation, but with 450 geothermal installed heat systems, some of which have been functioning since more than 22 years, we believe we can help promote alternative energy sources for heating as well.
Re: The technology already exists
Mr. Bassfeld - could you email me more info on the "technology already exists" - thanks.
Lynn M.
Re: The technology already exists
There are several companies engagingh in developing geothermal power projects in Australia. More info on the technology is at http://hotrock.anu.edu.au/ . There is also some good info on activities in South Australia at http://www.pir.sa.gov.au/dhtml/ss/section.php?sectID=2024
Guest (Earle)
To create passages and surface area for geothermal heat transfer to water consider a small hydrogen bomb set at a great depth. The radiation will be low and the much of the heat from the device will be usable with the geothermal heat. Heat exchangers and return of cooled steam or water will have to be returned to the formation. There are a number of technical details but none insurmountable.
Imagine. Clean energy with nuclear disarmament in the bargain. What's not to like?
Fracing an oil well with a nuclear device was done in New Mexico during the cold war. No control of what was going to occur after the blast. Plus, all the oil was radioactive. Fracing has advanced tremendously since that time, and is done worldwide on a daily basis at nearly all depths upto +20,000ft.
Guest (John Bill)
Laurie David to Protest Geothermal Plant
Larry David's activist wife Laurie and Robert Kennedy jr are planning on suing to stop the construction of a test Geothermal plant in California because they say it may hurt precious underground bacteria so vital to the environment.
Re: Laurie David to Protest Geothermal Plant
Please provide a link to substantiate your post. I couldn't find any reference on the ED website or via Google. Thanks.
Guest (hosro59@comcast.net)
Effect of high pressure steam and mineral contamination
I seem to remember that water used in this manner would pick up minerals that would tend over time to corrode or block pipes
bringing steam to turbines. Lower pressure steam could be distributed to homes and buildings for direct heating. Would not there be a "cycle" whereby dead steam would be sent back down to be re-heated? Are there maps, from geological surveys, that can provide a three-dimensional picture to get an idea of relative depths for efficient drilling to sources across the nation?
I lived in a community that smoothed its power demands to the utility by pumping water uphill to a resevoir at night and letting it run back downhill through turbines during the day. Energy storage needs to be looked at more thoroughly with different paradigms as to scale, as most utilities are designed for "economies of scale" but seldom contain the full life-cycle costs
versus more medium and smaller scale plants more directly sited to economic activity and human settlement. Fewer long distance transmission lines and rish of broad outages taking down a net.
Re: Effect of high pressure steam and mineral contamination
Carleton University in Ottawa heats several of its large buildings in the winter and cools them in the summer vis heat exchangers using ground water. This is not geothermal energy as is being discussed here, but it is in the same direction. As for the problem of possible enviornmental contamination with geothermal energy production, this problem is solved --- or one could say avoided -- by pumping the water back into the ground. In New Zealand where true geothermal energey is used, the problem of corrosion is solved also by pumping the water back into the earth. The matter of corrosion is a fact to be dealth with, and is not an extraordinary problem that limits the use of geothermal energy. It is dealt with by design, choice of materials, scheduled maintanance and scheduled replacement of machinery, pipes, etc.
A major problem with development of novel energy sources and production in North America is just that; they are regarded as 'novel,' and exotic. Even when and where they are proven, such as is the case with wind energy, micro-hydro, and wave-generated electricity. The general public, governments and also importantly, financial institutions, have a mindset that regards renewable energy as a sidebar to the REAL business of energy production from hydrocarbons major hydro sources. This is the reality, shrouded by the massive amount of information, opinions, pronounceamentos and predictions that suffuses the whole field. Had this not been the case, there would by now be energy production from these 'novel' by several orders of magnitude more than is the case now. Case in point; the hesitancy with which geothermal energy production is being approached. To quote Civil Rights leader Rev. Jesse Jackson, it is a case of "Paralysis by analysis." Why don't we "just do it now" for goodness sake?
A new model of product energy is based into this geothermal energy which has been invented in antique Creece in use of baths to heat water.
Now, if drilled 3.000 - 5.000 metres below, you´ll get water move up as hot steam and if you drop a cold water on this hot steam, you can creat lightnings when particles are hitting in the middle of drilled well.
Water cycle in the well evermore and produce all energy people will need.
Cost of drilling will be under 20 million dollars in depth of 5.000 meters and concidering the plant costs, efficient of energy will be better than using nu-clear power. Plus without waste and carbon dioxide offcourse.
I'm really liking the fact that more and more people are turning to cleaner sources of energy. I'm doing the same thing in my home as well. Just last year I had New Jersey plumbers install a geothermal heating system in my home. I couldn't be more pleased with the results, I've got a greener home and I'm saving a fortune on my heating bill.
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Guest (B. van Lew)
Additional information
Readers might be interested to know that there is a European project currently experimenting with energy extraction from hot dry rock (HDR) at a depth of 5000m (about 3 miles down).
The project is wel advanced at the main site is at Soultz-sous-Forets in France. Progress can be reviewed at the following web address:
European Deep Geothermal Energy Program http://www.soultz.net/version-en.htm
I'd be interested to know where this effort fits into Jefferson Tester's idea of universal geothermal energy. Any comments?
Regards
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Guest (James Randolph)
New Mexico Baca Geothermal study - it's not that easy.
please review http://geoheat.oit.edu/bulletin/bull23-4/art3.pdf
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