By David Wojick |December 14th, 2020|Energy|
There is a revolution coming in geothermal energy. How big it will be and how fast it can grow remains to be seen, but the revolutionary technology is here now.
We already know about the new technology by name — fracking. But that is fracking for oil and gas, the energy revolution we are already living on, that the greens hate. The geothermal revolution is fracking for heat.
Here is the technical bit. The Earth’s crust we live on is just a thin film wrapped around an 8,000 mile diameter molten ball. In some places under the deep ocean this crust is estimated to be just 3 miles or so thick. It is somewhat thicker under the continents but the point remains; it gets hot fast as you drill down into the crust. That heat is geothermal energy.
We have used geothermal energy to make electricity for a long time, but only in tiny amounts. California does the most in the US and its entire generating capacity is about the size of a single large coal fired power plant, about 3000 MW. The whole world is said to just have a minuscule 15,000 MW.
The obstacle to doing more has been that useful energy sources are hard to find. You need a confined reservoir of hot water in fractured crust rock. The reservoir size, location and temperature of the water are all determined by nature. Suitable sites have been very few.
Now all of this has suddenly changed. With hydraulic fracturing (or fracking) we can make these geothermal reservoirs where we want them, the size we want them, and where the heat is the temperature we want, especially very hot. This includes the so-called “supercritical” water at 400 degrees C, which is now used in the most advanced power-plants.
It is like the difference between living on wild edibles, if and when you find them, and farming. Fracking for heat is literally a whole new world. Of course there are still pesky things like cost, feasibility and regulation, but the principal is clear; the technology of revolutionary thermal energy has arrived.
The greens are in a bit of a bind here. Geothermal juice looks like the ideal renewable. Unlike wind and solar, geothermal electricity is constantly available and it is not a land hog. But the greens despise fracking and have labeled it evil. Some States and even whole Countries have banned fracking for oil and gas. Whether this applies to fracking for heat remains to be seen, since the fracturing processes are rather different.
How this dichotomy will play out is anybody’s guess. As they say here in the mountains: “What goes around, comes around.” That is, don’t start trouble lest it bite you someplace soft. The greens desperately need geothermal fracking, they just don’t know it yet.
The US Energy Department has a Geothermal Technologies Office and they are understandably optimistic. They project something like 60,000 MW of advanced geothermal juice capacity by 2050. Mind you this is still small, given that our present generating capacity is around a million MW.
The amount of geothermal generating capacity installed by 2050 could be much larger, for one simple reason. It is probably the only way to make wind and solar work. A number of analysts, including me, have pointed out that electricity storage on the scale needed to power America with intermittent renewables is impossible. But many States have mandated a high level of renewables, even 100% in extreme cases.
This makes geothermal the perfect renewable, because its power can be available whenever the intermittent generators cannot provide the power we need. The more power we want from renewables, the more geothermal capacity we will need. It is that simple. We could be talking about many hundreds of thousands of MW. If the technology works cost wise it might actually be better than unreliable, land grabbing renewables.
Happily there is a massive frenzy of geothermal research going on, much of it aimed at reducing the obvious obstacles. Searching the engineering and scientific literature for the last five years on the word combination “geothermal” and “research” yields over 100,000 technical articles. That is a lot of research.
So there it is. Geothermal energy is potentially the second fracking revolution. No question the heat is there, thanks to the big molten ball we call Earth. And now we suddenly have the technology to create the infrastructure needed to tap into it. How practical it is, and how acceptable, still remains to be seen. Interesting times lie ahead.
Author
David Wojick, Ph.D. is an independent analyst working at the intersection of science, technology and policy. For origins see
http://www.stemed.info/engineer_tackles_confusion.html
For over 100 prior articles for CFACT see
http://www.cfact.org/author/david-wojick-ph-d/
Available for confidential research and consulting.
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We can’t have geothermal because it can’t be monopolized, can’t be rationed, can’t be controlled only by energy companies.
It would cause a massive shift in revenue.
Interesting proposition. BUT I see at least two significant BIG problems.
1. The geothermal gradient. Most places not sitting on a volcano or equivalent (Yellowstone, Iceland) the gradient is 20-30C/km (depends on the rocks). Say 25C/km on average to access 400C. The well has to be ~16 km deep. The deepest fracking in the world is the Utica shale underneath the Marcellus. The parts fracked to date are under 2 km down. The parts nobody has tried yet (overlying shallower Marcellus is easier) average about 3.3km. Fracking requires hydraulic pressure greater than the rock ‘cohesion’ to induce fracturing That minimum hydraulic pressure obviously increases with depth.
Plus, shale is definitionally stratified from its marine deposition, and therefore ‘friable’ aka fairly soft and crumbly. At 16km, one is in basement hard rock (basalt, granite), much tougher and less ‘friable’. Dunno that the requisite hydraulic pressure could ever be achieved at requisite bulk scale.
2. The big present problem in geothermal e.g. in California and Iceland) has always been corrosion (the well pipe) and scaling (the heat exchanger from the geothermal brine to the necessarily very pure turbine driving steam/water), since deep waters are always briny. Fracking does not solve that known problem.
Rud: “Fracking requires hydraulic pressure greater than the rock ‘cohesion’ to induce fracturing That minimum hydraulic pressure obviously increases with depth.”
Rule of thumb (in absence of tectonic pressures) is pressure for fracking is 80% of lithostatic (overhead) pressure because of the fluid pressure in tiny voids which contain the oil or gas in the shale.
Regarding depths, the 2 -3km ‘limit’ is for use of sized, rounded pure quartz sand to serve as ‘proppants’ in the fractures created in the shale. With greater depth, the crushing strength of the sand grains is exceeded. The sand is mixed with the frack fluid so that it lodges in the opened fractures holding them open for exit of the hydrocarbons.
For deeper plays, you have to use manufactured high strength ceramic “sand”. These are generally aluminosilicate based. A US based manufacturer (Carbo Ceramics?) offered a product suitable for the ~ 20,000ft Deep Horizon in the G of Mexico a few years ago. I researched and wrote a multi-client technical and economic study on the industry 5yrs ago as a contractor.
https://roskill.com/news/roskills-new-report-on-north-american-porppants-and-frac-sands/
Geothermal works in New Zealand. It produces about 17% of electricity generated. Some bores have restricted offtakes to allow them to replenish. Geothermal base load output allows for less reliance on gas and coal based generation.
South Island??? North Island? Both?
Then why do they need all those wind prayer wheels?
Tapping geothermal for heat is reasonable and can be cost-effective for home heating using closed-loop systems. Trying to use deep geothermal hot water for generating electricity is a nightmare of corrosion and calcification. Geothermal water is laden with corrosive salts, minerals and gases in equilibrium. When you tap these reservoirs and bring the hot water to the surface, the minerals and gases are released as the pressure and temperature drops. Good projects for using up government grant money, bad for generating electricity economically.
Geo-thermal for heating your house is a misnomer.
At the depths reached for such systems, the ground temperature is controlled by the yearly average of the air temperature, plus heating from the sun.
The contribution from true geo-thermal heat is too small to measure.
If this new geothermal technology provides cheap energy, the greens will hate that too. The only that will make them happy is everybody is poor, except themselves, and living in a communist utopia. The greens hate people more than they love the earth.
Unfortunately, getting to the depth in non-volcanic areas really aren’t that feasible. Plus the high heat destroys the drilling equipment. The Russians had an advantage in that they were just drilling straight down. They didn’t really care where they were. If you’re drilling for reliable heat sources, you’re going to care and at those depths, the MWD tools are going to die. They can do some high temps, but not the ones that make Geothermal viable. It’s also very hard on all the pipe and other equipment. After 10 years in the oilfield, I’d say this isn’t really doable right now with current tech.
Another point to ponder is the quality of the steam and water from fracked wells. It contains minerals and volatiles, some quite acidic. Maintenance can be relatively high dealing with steam rotor and valve corrosion and pipe mineral deposits.
I would imagine the water from the well wouldn’t be directly flashed to steam, but would instead be used to heat surface water.
There would still be problems with the pipes that carry the deep water, but at least the turbine would be protected.
I was in California in the late 80s and the utilities made strong efforts to tap geothermal resources. It was available and reachable in areas. The problem was it was not suitable for continuous long term energy production due to the corrosiveness of the underground environment. Maybe there are better materials available today, but until I hear that has been addressed I will be skeptical.
The drilling around Yellowstone can’t begin too soon.
Another Obama bust:
https://gvwire.com/2020/12/14/opinion-another-green-subsidy-bust/
If the money already spent and subsidized for wind and solar were instead invested in conventional ground-loop geothermal electric heating and cooling, we would have saved amazing amounts of power. In the US, ground loop geothermal saves 25 to 45 percent of the energy expended for space heating and cooling. This is a demonstrated performance, works 24/7, and doesn’t require huge energy investments to produce, unlike wind and solar.
As some of us keep explaining, ground loop is stored solar, not geothermal.
They tried new Geothermal using fracking in Australia and elsewhere.
Broken drill heads, casing failures, accidents, toxic minerals, uneconomic (requires high carbon tax & green incentives), bankruptcies. So it’s a bit hit&miss.
New Zealand has some good geothermal power generation because it has some volcanic activity close to the surface but is better behaved (consistent without the big eruptions & movement). YMMV
“The reservoirs can also contain traces of toxic heavy metals including mercury, arsenic, and boron. That said, the pollution associated with geothermal power is very low, and just a tiny fraction of what we see with coal power and fossil fuels.”
https://www.solarreviews.com/blog/geothermal-energy-pros-and-cons
Drilling down to the reasons behind geothermal’s failure
https://www.theaustralian.com.au/business/business-spectator/news-story/drilling-down-to-the-reasons-behind-geothermals-failure/c61b59541dc7e65d6eca3bf4f8057efc
Geodynamics changes focus to solar, storage and hybrid energy
https://reneweconomy.com.au/geodynamics-changes-focus-solar-storage-hybrid-energy-56661/
Dutch geothermal sector calls for clearer conditions and better support
https://www.thinkgeoenergy.com/dutch-geothermal-sector-calls-for-clearer-conditions-and-better-support/
Geothermal is like wave energy. Seems obvious on paper until you get into the fiddly bits of actual engineering. Whereupon it becomes too expensive even with massive taxpayer subsidies.
Our infamous climate moaner Dr Tim Flannery used to spruik hot rock geothermal. Hundreds of millions were sunk into it only for the whole thing to collapse in embarrassing failure.
Another Flannery fail: geothermal project scrapped (2016)
In practice geothermal is like any other energy source. The more concentrated it is the more economic. So geothermal projects in Iceland and New Zealand work because they sit on top of magma chambers. The rock temperature is so hot that only a few wells are required and the steam quality is high. Of course if the supposedly dormant volcano erupts you have done your dosh even more spectacularly than Flannery did with his hot rocks project.
When they finally settle people in Antarctica due to “gerbil worming”..
…. they will be able to access geothermal down there, as well. 🙂
As I understand it, the failure of the South Australia geothermal project was not the heat source but the difficulty of extracting steam at consistent pressure from the wells. Essentially the wells leaked because of naturally occurring fissures in the rocks between the hot source and the surface. It seems likely to me that geothermal will only work if the source of the heat is relatively close to the surface as in geyser regions such as in NZ and Yosemite Park in California. This reduces the possibility of steam loss into the surrounding rocks and may allow lining of the well to further enhance reliable steam production. Where the heat source is deep within the ground, it may not be possible to line the full extent of the well and thus the failures observed.
Why don’t we experiment with old deep capped dry wells from the oil and gas industry ..
The dry wells would be in non hydrocarbon bearing deosits by definition ..
Some of the more recent ones may have been fracked ..
There are thousands of these wells around the country ..
If the rocks were hot enough to make geothermal energy attractive, there would have been no hydrocarbons to drill for in the first place.
I suppose if one can find a source of very hot rock at a shallow depth, and or mine the heat stored in the rock, you can run a reasonable plant like Beowawe, Nevada. But this occurs in very few places. If you are planning to make this work anywhere, like a CCNG or Coal plant can be placed anywhere, then you are faced with the fact that 400C rock is extremely deep — way beyond drilling technology — and the power density is about 60mW per square meter. That’s milliWatts per square meter, folks.
Iceland is an island of fire from volcanos and ice from glacier. Their hydroelectric generation is from glacial runoff and their heating is volcanic geothermal. They use little to no oil or wind. More power to them…pun intended.
Would love if you read the geothermal section of the FREE book that has been available for some time. If you like that section you will probably love the rest of the book. Invaluable when you have these discussion who are not up on the science. The books name is: Sustainable Energy – without the hot air by David JC MacKay. He sells it on Amazon for $151 for the hardback, or he freely allows you to read it online. Google it to go to withoutthehotair dot com. Chapter 16 explains geothermal limitations, based on the science. As was said before, low energy value in most places, better if you sit on a continental fault line, or a volcano. Geothermal heat pumps would save lots of electricity most anyplace, though.
As others have explained here you just do not understand the nature of the Green. I suggest you go look for something that actually works that they approve of. I have asked this before never is there an answer. Most of us would applaud this new energy source geothermal but it will be a nightmare as far as they are concerned and they will actively fight to prevent it. Because of the acquiescence of large numbers of fools they get away with it.
I have given up long ago the idea that this is about emissions and the temperature of the planet it’s not. What they do is driven by the fact they hate capitalism and everything they do diminishes it. They are not content with just affecting energy they wish to damage if and eliminate our civilisation. These are tools to achieve their aims not real in fact. I suggest look at the rise in CO2 then look at the changes in temperature that we have, do you see any correlation. I don’t. Look at the large effort that has been put in to diminishing the Western world’s emissions and go back and look at the data again do you see any change? 30% of the world’s emissions is China but when did you last hear and environmentalist concerned about that?
The main problem with geothermal is that the water gets loaded up with corrosive and precipitating chemicals. These can cause scale, corrosion, or both. This occurs in the plant, as well as the casing of the well itself. These problems with the water have proven an insurmountable obstacle for many geothermal plants, and I see nothing in fracking that will alleviate that problem.
w.
Thank you Mr. Eschenbach. I looked thru most of these comments for someone to mention what is indeed the “main problem” with these projects. Ask anyone in the Cal oil field service biz who has ever worked on or tried to log these wells, and they will tell you that they would much rather even work on steam injection (also awful work) than in geo fields.
The people of the world are already facing well into 13 figures of shirked oil and gas field asset retirement obligations, accrued for over a century We don’t need even more from geothermal pumper dumpers who will unload their trash cans of corroded/eroded wellbores and yards full of NORM laden tubulars onto the rest of us.
There was a geothermal energy project in the UK, following the 1973 oil crisis. It was based in a granite quarry in Cornwall, chosen because the geothermal heat flow there, at 120mW/m^2, was the highest in England. They drilled three wells to approximately 2.5km and fractured the rock between by hydraulic pressure to allow cold water to be circulated and recover the heat. But the water recovered was not hot enough to drive a steam turbine, and it would have required drilling at least a further 1km to achieve that objective. The project ran from 1977 to 1980, although studies continued at the site for a further elven years. https://en.wikipedia.org/wiki/Rosemanowes_Quarry
Another energy technology revolution?
How many is that this week already?
Yawn
So, let me get this right.
We are going to take heat which is currently safely stored underground and release it into the atmosphere of the planet to cool it down.
“Now all of this has suddenly changed. With hydraulic fracturing (or fracking) we can make these geothermal reservoirs where we want them, the size we want them, and where the heat is the temperature we want, especially very hot. This includes the so-called “supercritical” water at 400 degrees C, which is now used in the most advanced power-plants.”
The above quote by Dr. Wojick is a statement of hopeful optimism but, not, to my knowledge based upon a hydraulic fracturing breakthrough. We have been able to “frac” deep brittle rocks for a long time, given the right situation. That has not been the sole or main limitation to high temperature geothermal energy development, rather there are many physical and economic challenges as mentioned by other writers, above. Regardless, I do thank the author for writing about his opinion because continuing targeted research is worthy, IMHO and many significant developments in “fracing” have been made during the past 25 years, especially.
If I am incorrect and out of date, please inform me of the breakthrough operating geothermal projects.
While it’s become clear from reading the interesting article above that geothermally derived energy is right up there with wind and solar because it’s totally useless at producing cheap reliable electricity but sounds plausible enough to people who didn’t study engineering, the fact is that the problem they’re trying to solve has been solved already.
That the problem HAS been solved is most manifest in communist China where they’ve totally proved that, building stonking great big, beautiful coal power stations hand over fist that loft copious quantities of brand new clean plant-enriching carbon dioxide heavenwards not only gives them an abundance of clean cheap reliable electricity but more importantly, does NOT cause global warming.
Because if it did Al Gore would have moved to Canada by now.
It also means there’s more than enough money around to pay politicians in democracies to NOT understand this.