'Exponential Spin-up' In Geothermal Energy Projects Brings Hope for Green Power (newyorker.com) 65
Earth's core "burns with an estimated forty-four trillion watts of power," the New Yorker reminds us — enough to "satisfy the entire world's energy needs" with a power source that's carbon-free, ubiquitous — and unlimited. (Besides running 24 hours a day, one of geothermal energy's key advantages is "it can be used for both electricity and heating, which collectively account for around 38% of global climate emissions...")
And one drilling expert tells them there's been an "exponential spin-up of activity in geothermal" energy projects over the last two years. (Ironically it was the fracking boom also brought an "explosion of new drilling practices — such as horizontal drilling and magnetic sensing — that inspired a geothermal resurgence.") In 2005 one research team calculated that just 2% of the heat just four miles underground in America "could meet the entire country's energy needs — two thousand times over," according to the article.
So their new article checks in on the progress of geothermal energy projects around the world, including a Utah company using a diamond-bit drill to dig nearly a mile into the earth to install a 150-ton steel tube surrounded by special heat-resistant cement — all to create "a massive straw" for transporting hot water (and steam). The biggest problem is drilling miles through hot rock, safely. If scientists can do that, however, next-generation geothermal power could supply clean energy for eons... At 6:15 P.M. on May 3rd, cement had started flowing into the hole. Four hours later, part of the cement folded in on itself. The next morning, the cement supply ran out; the men had miscalculated how much they needed. This brought the three-hundred-million-dollar operation to a maddening halt... The cement truck from Bakersfield arrived around 8:30 P.M. By ten-thirty, the men were pouring cement again, gluing the enormous metal straw in place. Next, the team scanned the borehole with gamma rays...
And one drilling expert tells them there's been an "exponential spin-up of activity in geothermal" energy projects over the last two years. (Ironically it was the fracking boom also brought an "explosion of new drilling practices — such as horizontal drilling and magnetic sensing — that inspired a geothermal resurgence.") In 2005 one research team calculated that just 2% of the heat just four miles underground in America "could meet the entire country's energy needs — two thousand times over," according to the article.
So their new article checks in on the progress of geothermal energy projects around the world, including a Utah company using a diamond-bit drill to dig nearly a mile into the earth to install a 150-ton steel tube surrounded by special heat-resistant cement — all to create "a massive straw" for transporting hot water (and steam). The biggest problem is drilling miles through hot rock, safely. If scientists can do that, however, next-generation geothermal power could supply clean energy for eons... At 6:15 P.M. on May 3rd, cement had started flowing into the hole. Four hours later, part of the cement folded in on itself. The next morning, the cement supply ran out; the men had miscalculated how much they needed. This brought the three-hundred-million-dollar operation to a maddening halt... The cement truck from Bakersfield arrived around 8:30 P.M. By ten-thirty, the men were pouring cement again, gluing the enormous metal straw in place. Next, the team scanned the borehole with gamma rays...
Nuclear fission inside of the earths core. (Score:2)
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estimated forty-four trillion watts of power, seems like a lot to me, but a tesla magnet seems like a lot to me too.
That number seems quite small. If I'm doing the math right, the US alone generates about a half a terawatt, or about 1% of the cited number. That doesn't make 44 TW seem all that large.
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Maybe that's per day?
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TW, as a unit of power, is continous. If it was TWh, then it could be "in a day"
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Earth's core "burns with an estimated forty-four trillion watts of power," the New Yorker reminds us â" enough to "satisfy the entire world's energy needs" with a power source that's carbon-free, ubiquitous â" and unlimited.
SKROOB: Ah, Planet Earth, and ten thousand years of power.
HELMET (mask up; to Sandurz) The way he runs things, it won't last a hundred.
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About 4/5ths of geothermal heat comes from radioactive decay.
https://www.withouthotair.com/... [withouthotair.com]
As I said before, geothermal energy comes from two sources: from
radioactive decay in the crust of the earth, and from heat trickling through
the mantle from the earthâ(TM)s core. In a typical continent, the heat flow from
the centre coming through the mantle is about 10 mW/m2. The heat flow
at the surface is 50 mW/m2. So the radioactive decay has added an extra
40 mW/m2 to the heat flow from the centre.
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The pressure is not relevant for unstable isotopes in the earth to decay, they would do that with or without pressure. But I would also like to know how much of the geothermal heat harvested comes from the radioactive decay, and how much is just residual heat from when the planet formed.
My impression is most of it. That was one of the conundrums of the 19th century: given increasing evidence of a very old Earth, how does its core stay hot? If it was just a cooling sphere of rock, it should have cooled entirely a long time ago. The discovery of radioactive decay provided an answer, just like discovering fusion answered where the Sun's energy comes from.
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Our asses sit on a massive nuclear fission reactor. This one is at least shielded by a decent amount of rock. But, there's worse: someone irresponsible put a much bigger, completely unshielded fusion reactor mere 8 light minutes from here! It emits deadly radiation: while fortunately at least on our side there are two weak shields: one magnetic, one oxygen, the shields are inadequate, causing numerous fatalities due to radiation-caused cancers. Even worse: when that reactor malfunctions, it's expected t
Re: Nuclear fission inside of the earths core. (Score:2)
I wouldn't call it a fission reactor since there isn't a chain reaction happening. It's just individual decay events.
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So the proper name is "cold fission".
On the political upside ... (Score:5, Insightful)
Accessing geothermal meets the technical definition of "drill, baby, drill" ... :-)
Re:On the political upside ... (Score:4)
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Geothermal is a good replacement for nuclear for those who don't like that technology for whatever reason.
It depends on the rate of energy consumption per area. Geothermal energy produces about 50 mW/m2: https://www.withouthotair.com/... [withouthotair.com]
Here's a chart showing consumption of energy per area for several nations: http://www.inference.org.uk/ma... [inference.org.uk]
That chart is about ten years old but likely still fairly representative of current consumption. Oh, and note that the chart is log-log scale which can throw people off on what the distance between two points mean in reality.
Nuclear fission produces about 1000 W/m2: ht [withouthotair.com]
Re: On the political upside ... (Score:2)
There are vast tracts of empty desert suitable for solar power.
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And there are vast tracts of empty desert suitable for twenty four hour a day geothermal power.
Re: On the political upside ... (Score:2)
We should do both!
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There are vast tracts of empty desert suitable for solar power.
If there are such vast tracts of empty desert suited for solar power then why is it after decades of subsidies for solar power we still see solar power produce so little of our primary energy supplies? I thought I'd take a quick look at how much of our energy comes from solar on Wikipedia but it's such a small contribution that its lumped in "other" along with wind, biomass, and perhaps more. https://en.wikipedia.org/wiki/... [wikipedia.org]
This land is not suited for solar power, and this is in large part because a dese
Re: On the political upside ... (Score:2)
I didn't say there are no reasons we don't use more solar, just that not having the land for it isn't one of them.
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I'm saying that we'd need more than empty land to make it suited for solar power, there would need to be built up infrastructure around it to make it competitively priced against alternatives for energy. There are not large tracts of empty desert suited for solar power because these deserts are far from where the electricity is needed, in large part because people tend to live near land that have enough rainfall to grow food and well water to quench their thirst.
Being empty land is insufficient for being s
Re: On the political upside ... (Score:2)
Again, this is the ONLY part I was referring to: "that is land used that rarely has a dual use. Plants don't grow in the dark, and people need light to see, close off the land below from sunlight and that is land that cannot be used for much." I am NOT claiming to address all challenges with solar power.
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There are also vast tracks of unused rooftops suitable for solar power. As a bonus, they power gets generated where it's used. Sprinkle in a bit of storage and you don't even need any utility upgrades.
=Smidge=
Re: On the political upside ... (Score:2)
Utility scale solar is much more efficient.
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Define 'efficient.'
They use the same panels so there's no advantage there. The inverters and related equipment operates at essentially the same efficiencies (90%+). If you generate it locally then you skip the transmission and distribution losses which is usually estimates at about 5%.
We are already at the point where renewable energy needs to be curtailed because the distribution grid can't get the power from where it's being made to where it's needed. A solar plant that isn't generating because there's no
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I think that you might be off about solar being rarely dual-use. Every solar panel on top of a building is dual-use solar, for example. There's definitely development potential for using solar panels to provide shade to crops that need it.
There are also possibilities like solar carports, shaded parking.
Unlike wind turbines, which as you mention can cause damage if they fail catastrophically, solar panels can be attached directly to structures without much issue.
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I think that you might be off about solar being rarely dual-use. Every solar panel on top of a building is dual-use solar, for example.
How much does rooftop solar cost compared to utility scale solar, the kind with panels amounted a waist height out in an otherwise empty field? Some studies put it at about double the cost: https://en.wikipedia.org/wiki/... [wikipedia.org]
While looking at the cost of rooftop solar vs. utility scale solar take a look at how rooftop solar compares to onshore wind, hydro, geothermal, or nuclear fission. Rooftop solar doesn't make sense for electricity supplied to an electrical grid. It can make sense for off-grid power, pe
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... outside of grabboids or some hereto undiscovered species, there isn't a lot of ecology down there for us to impact by tapping into this energy source.
This video [youtube.com] begs to differ. And given the hardiness and variety of life down there, I'm not entirely comfortable at the prospect of it making itself at home on Earth's surface.
On the one hand, these organisms live under huge pressures, temperatures, and radiation levels, so the environment 'up here' seems pretty incompatible with what they're used to. On the other hand, if they're strong enough to survive in those extreme conditions, I wonder what they might do when lots of them are brought to the surface
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Geothermal is vastly superior to nuclear. No fuel, lower CO2 emissions, far less risk, fewer restrictions on where it can be deployed, and above all lower cost.
It can be used world-wide too, no issues with exporting the technology. If we were to say that nuclear is essential for developed nations, we would be saying that ever developing nations needs nuclear as well.
How "green" this power will be... (Score:4, Interesting)
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Re: How "green" this power will be... (Score:5, Informative)
My own conclusions were close to what you're saying. There are many significant drawbacks, some of which altered the direction of the company.
1. Drilling was by far the most expensive part of the process. Also, competition for the super heavy drilling equipment with the oil industry meant waiting and scheduling. Transportation of the heavy equipment was non trivial, time consuming, and expensive.
2. Once a hole is drilled and plant is in operation there was signifyicant excess heat that was dumped into the surrounding environment
3. All the existing open loop technology sees a significant drop off in well pressure, and therefore energy production, by the year... efficiency drops of 5-10% per year are common .
I did a quick scan of the article. These drawbacks don't seem to be addressed.
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The article didn't get much into the technology. Correct me if I'm wrong, I didn't read it word for word.
For open loop systems you are looking for reservoirs of hot brine, which you pump up one hole by pushing stuff down another hole... so it would obviously depend on what's down the abandoned hole.
The tech I worked on (just the specs and business plan, they didn't have a test site until after I left the company) was a clo
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Those are the kinds of things that these guys are trying to resolve. It's still a rapidly developing technology, so it's hard to say what the outcome will be. Well worth pursuing though.
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I worked for a old engineer businessman who acquired 5 patents around geo thermal energy generation around 15 years ago. Worked on the business plan for him, and did competitive market analysis at that time.
My own conclusions were close to what you're saying. There are many significant drawbacks, some of which altered the direction of the company.
1. Drilling was by far the most expensive part of the process. Also, competition for the super heavy drilling equipment with the oil industry meant waiting and scheduling. Transportation of the heavy equipment was non trivial, time consuming, and expensive.
2. Once a hole is drilled and plant is in operation there was signifyicant excess heat that was dumped into the surrounding environment ... usually rivers or lakes causing fishkill and growth of algae.
3. All the existing open loop technology sees a significant drop off in well pressure, and therefore energy production, by the year... efficiency drops of 5-10% per year are common .
Couple of thoughts.
First, we've had 15 years to make fracking cheaper and build more gear. I'm sure there would be competition for the drilling rigs but if we're trying to build a zillion geothermal plants, some bright spark will supply them.
Second, I think the more recent approaches are closed loop. The spent water gets injected into another well. I don't know what that does to the cost and whether it makes economic sense.
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Open loop! Wow, I assumed they would operate a closed loop system with a heat exchanger to keep all the geothermal fluid with its potentially nasty dissolved minerals well away from things like turbines...
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> signifyicant excess heat that was dumped into the surrounding environment
This is true for literally basically all types of thermal-cycle power plant. Why do you think power plants are so commonly build on shorelines, lakes, and rivers? When those resources aren't available, they build cooling towers. (Which, although iconic for nuclear power plants, are not unique to them - nor does every nuclear plant have them.)
Gas turbines don't do this because they reject heat directly to the air, rather than to w
Re: How "green" this power will be... (Score:2)
The data I saw at the time was for various smaller test sites, and was in line with what I said. The output drop over time is was a huge unknown a large management concern.
Re: How "green" this power will be... (Score:2)
Sounds like a perfect solution fallacy.
aaaaand it's gone (Score:2)
Re:aaaaand it's gone (Score:4, Insightful)
Earth Source Heat (Score:3)
Exponential growth (Score:1)
Back in aught-nine, I was doing a stint in grad school. A fellow student was writing a paper on the economic feasibility of solar-powered something-or-other as opposed to the diesel version.
The cost numbers just about closed, but not quite, unless the then-recently-rising cost of crude oil were extrapolated into the future as exponential growth. It almost worked. Except by that time the recession had hit and oil dropped off a cliff. Not such a good exponential fit anymore.
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should have dark tubes on their roofs
I have them and I have been preaching for them for quite a while.
Re: Exponential growth (Score:1)
So where I am outside of Boston, we just came off the coldest January/February in years. Mean temperature 26F for 32 days straight. Nightly lows around 10-20F, sometimes daytime lows below freezing as well for a few days straight.
Sure, during the day my south-facing roof could get me some hot water. But since a good absorber is also a good emitter, during the ~16 hours a day that my roof doesn't get direct sunlight in the winter from a combined of low sun angle (24 degrees elevation at noon on the winter so
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> I can't see such a thing working in the winter at all
Evacuated tube systems have existed for close to a century now and can work down to -40C and still produce water over 60C in those conditions.
They are expensive and bulky so they're not super common, but they do exist.
=Smidge=
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Not even theoretical, you can go buy one of these systems right now. When I say they exist I mean they are commercially available and have been for decades.
=Smidge=
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I live in the Midwest USA and the weather forecast shows below freezing temperatures tonight. This isn't a matter of "brainwashing" to need fuel for warm water, it's a matter of practicality.
Since I'd need a water heater for warm water for much of the year there's little utility in solar heating of water. Natural gas is pretty cheap still even with increased global demand out of the USA from exports to Europe from cutting off Russian natural gas exports. I had an air-source heat pump installed some years
Someone should figure out (Score:3)
What happens when you cool an entire continents with of crust and it contracts. I'll bet the results aren't pretty.
Seems like old is new again (Score:2)
This is local to me and I don’t see how this is new:
https://www.calpine.com/ [calpine.com]
https://www.lakecountyca.gov/9... [lakecountyca.gov]
https://en.wikipedia.org/wiki/... [wikipedia.org]
And has some not so green environmental issues:
https://www.lakecountyca.gov/6... [lakecountyca.gov]
As well as early performance issues:
https://www.energy.ca.gov/powe... [ca.gov]
Sometimes I can see the steam rising from the cooling towers from my back deck in Cobb though I’m not sure which site it is.
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a known thermal gradient, and is moving that heat at conduction-through-dirt rates
consistent with that gradient. You'd have to run a heat engine to bypass a LOT
of vertical distance, in the downward direction, to tap that.
And, as you tap it, the bottom of your heat engine gets cold. That means
it's not sustainable, unless you find a magma flow and tap the heat of a river of molten rock.
The sustainable 'amount of ener
Obviously this will not mean anything... (Score:2)
...if it does not deliver maximum profit to the ultra-rich.