Geothermal or Fusion

https://physics.stackexchange.com/questions/21365/should-we-forget-fusion-and-focus-on-geothermal-power

Well do you think that the billions being spent on chasing Fusion energy would be put to better use developing deeper drilling technologies that will overcome those shortfalls...? ...and no mention of the possibility of curtailing the eruption of the Yellowstone super volcano that might destroy civilization as we know it..?

However, for the rest of us, I remember hearing the refrain, "Just ten more years . . ." over thirty years ago.

And for 30 years before that, it was on the other side of the spectrum.

How much money has cumulatively and globally been spent on nuclear fusion research?

Outside of large amounts spent on military fusion research for nuclear weapons, I’d guess $50 billion.

The current international ITER project in France is expected to cost $20 billion. The US National Ignition Facility $4 billion. The UK/Europe Culham facility (JET etc) has cost maybe $1 billion.

Fusion has always been the energy source of the future - always has been, always will be the joke has it. The science has been shown to be awfully difficult to implement technically, but they are getting closer to getting

… (more)

What about geothermal...?

The US Department of Energy (DOE) is investing significantly in geothermal energy research and development (R&D) to advance technologies and overcome barriers to deployment. The DOE's Geothermal Technologies Office has invested over $470 million in geothermal R&D since 2010. This funding supports various initiatives, including enhanced geothermal systems (EGS) research, pilot projects for EGS, and community geothermal heating and cooling projects.

Why aren't we spending more on something that actually works...we need to turn this around...imo

“…the possibility of curtailing the eruption of the Yellowstone super volcano that might destroy civilization as we know it.”

Two conjectures for the price of one.

I agree with redfred in #2. Downtown Boise Idaho USA has quite a few buildings enjoying geothermal heat… have been for, I dunno, a century or so. However, just a mile or so from the sweet spot, drill and you find… nothing. Good drinking water, but no heat.

Besides, I hear that someone will figure out how to harness fusion within ten years or so.

A report claims Yellowstone's geysers are preventing a super-volcano eruption. This has been suspected for a long time, but measured data confirming some assumptions is progress.

The simplified two-dimensional diagram of their measurement system brought a thought to me. If the geophone sensors were in a two-dimensional pattern on the surface, then a three-dimensional "holograph" of the magma cap could be mapped.

..."How large is the magma chamber that is currently under Yellowstone?

The magma chamber is believed to be about 40 by 80 kilometers across, similar in size to the overlying Yellowstone caldera. The top of the chamber is about 8 km deep and the bottom is around 16 km deep.

However, the chamber is not completely filled with fluid magma. It contains a partial melt, meaning that only a portion of the rock is molten (about 10 to 30%); the rest of the material is solid but, of course, remains hot.

The method that scientists use to discern this information is similar to medical CT scans that bounce X-rays through the human body to make three-dimensional pictures of internal tissue. In an analogous manner, a method called seismic tomography uses hundreds of seismograms to measure the speed of seismic waves from earthquakes and small, intentional dynamite explosions--data that allow geophysicists to make 3-D pictures of structures within the Earth. Scientists compare these seismic velocities, and infer the composition from deviations of these from average, thermally undisturbed values."...

That's a lot of free heat available for clean energy....

https://www.usgs.gov/volcanoes/yellowstone/questions-about-yellowstone-research#:~:text=The%20magma%20chamber%20is%20believed,completely%20filled%20with%20fluid%20magma.

There are fundamental differences between creating research, studying (reading) research, and implementing research. (Implementing research is at the heart of engineering.) Presenting a cost/benefit analysis between technologies, still creating research (fusion) and implementing research (geothermal), displays the analyst's bias more than providing useful financial information.

The other "geothermal" thread recently started presents a new drilling technique using microwave energy (creating research) instead of traditional mechanical drilling technology. As the new approach was presented, I identified a clear problem. If the researchers can address that problem, they may have a novel approach to drilling that might produce additional benefits. I wouldn't criticize the cost/benefit of this research until actual benefits (if any) are found.

The probability of Yellowstone's super volcano erupting is predicted to be only 0.00014%. A claim to prevent such a low probability from happening sounds more like a snake-oil salesman's marketing boast. I suspect that is why this outlandish claim was not made. On another note, the similar calculated probabilities of a super volcano eruption and a large asteroid impact with the Earth are an interesting correlation. Correlation does not mean causation. Correlation can prompt more research, though.

(Implementing research is at the heart of engineering.)

And in engineering, there are (2) types of engineers. theoretical and practical,.

where theoretical is basically the study of engineering as in research, and practical which is implementing..

when I look to hire, I look for the practical engineer. And if one were to hire a theoretical engineer for practical purposes, it rarely works out. At least I never experienced it working out.

My opinion, the simple answer is it all depends on location and demand.

a place like Iceland, with the exception,of maintenance geothermal is basically free… after the infrastructure is in.

Without the thermal then fusion is more cost effective.

..."

• In 2022, there were 3,965 MW of geothermal electricity plants in operation in the U.S.—the most of any country—and generation has been growing at 3% per year.⁷ Electricity generated from geothermal plants is projected to increase from 16.5B kWh in 2023 to 37.2B kWh in 2050.^8,9
• In 2021, California and Nevada had 95% of U.S installed geothermal capacity.⁷

https://css.umich.edu/publications/factsheets/energy/geothermal-energy-factsheet

..."The first geothermal area to be exploited for commercial electricity generation was The Geysers, a complex of 22 geothermal power stations located in Sonoma and Lake counties of California, which was commissioned in September 1960.^[1] The complex was then developed into the largest geothermal field in the world, with a nameplate capacity of 1,517 MW and an annual generation of 6,516 GWh in 2018.^[2][3]"....

https://en.wikipedia.org/wiki/List_of_geothermal_power_stations_in_the_United_States...

"With investment and support, however, the cost of geothermal could plummet by 80% by 2035, according to the IEA. That would make geothermal “highly competitive” with wind and solar paired with batteries."...

https://www.linkedin.com/pulse/geothermal-rare-renewable-energy-winning-favor-trumps-america-o2yee

There are lots of predictions about fusion being available "soon." But I think it is still decades away from being practical. Therefore, geothermal. I think geothermal could be done now if someone wanted to invest in a couple of deep wells and the equipment to harness the heat. The oil companies probably have the drilling technology needed.

Minimal damage to 250 buildings? ..out of how many hundreds of thousands?...seems quite minimal to me....It's well known that fracking causes, or can cause some aftershock type activity, when I lived on the west coast we used to get these 2-3-4 scale 'earthquakes' all the time, sometimes several a week, after a while it was hardly noticeable to me, if at all....ask a Californian about minor shocks...so I don't consider this a serious problem, just a slight annoyance that is short-lived....probably bogus insurance claims account for nearly all of these incidents....concrete cracks as it settles over time....

Yes only 250 buildings, over 70% of them are historic buildings dating back to the 15th / 16 Century. Over 55% are still not usable to date due to the damage caused which had nothing to do with "bogus" insurance claims. This is Germany, not the USA !!
It has put a lot of people and small businesses out of work. because of the damage caused.
Just imagine what would have happened in a large city, like New York or LA or Washington DC. where you have large Skyscrapers and houses that suddenly raised 12 inches on one side!, or the infrastructure below ground, Gas and Water pipes fracturing etc.
The problem lies in the drilling, you don't know just what lies 1 mile or two below the surface until you start drilling.
As for your comment "short-lived" annoyance, tell that to people who can no longer live or work in their homes and offices, shops etc. almost 20 years later... and you have to remember, most of the building damaged were built in the 14,15th and 16th Centuries... Concrete, in the form we know used for building, was not known until 1824 when Joseph Aspdin developed "Portland Cement "in England.
As you can see in the foto, not your modern Concrete buildings !

Also the small historic Town is famous due to the fact that Dr. Johann Faust was murdered there in 1548. He was a well-known Alchemist, Magician and Astrologist, so Staufen was and still is a very popular tourist resort.

Well clearly mistakes were made in this example, first the geology was not taken into account, and secondly the wells were drilled in close proximity to the buildings, I mean you could hit them with a rock close...so this was an ill conceived project....that being said the damage can be repaired in time and compensation paid, so not really the catastrophe you purport...and not really relevant to today's standards of planning, more just a cautionary tale of improper planning....

https://yosemite.epa.gov/oa/eab_web_docket.nsf/Filings%20By%20Appeal%20Number/A2CFC125A4A7EED285257F4000592267/$File/Attachment%2015...17.pdf

Over here (USA) high pressure water injection for fracking for oil production has been linked to earthquakes.

<...Geothermal...> is commonplace in Iceland and frequently encountered in Switzerland.

Geothermal is here already and in a big way in many countries. Even cool Northern Ireland has some at geoenergyni.org. Even when the crust is thicker and cooler storing heat and coolth underground can act as a virtual battery for the most intermittent part of wind and solar electricity output. Why store electricity in an expensive battery when you already own the ground you stand on?

Even the use of ground temperature is very useful even without the deeper tapping into hot spots. Many larger buildings have used the 20-40 degree difference as a great way to greatly increase heat pump efficiencies. This is a sure bet.

Fusion energy is currently a scientist/physicists dream project that may be 50-80 years before production scale energy by my prediction. But once we get there (if ever that is), it will pay for itself unlike so many super high expense projects that are purely learning centers.

Commonwealth Fusion Systems
117 Hospital Rd
Devens, MA 01434

One star.

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The race is on to capture the ‘heat beneath your feet’

...But unlike capturing fossil fuels, geothermal has unique qualities.

“It has the lowest life cycle carbon footprint of any renewable energy technology, less than solar and wind. It has the smallest environmental footprint of all energy technologies. So what we see are environmental organizations seeing these benefits that they far outweigh and surpass all other energy technologies,” he said.

“I think we are seeing global politics as they are that there is a need for baseload energy that is local and with an American name that we can generate right here without relying on global supply chains, which are now in a lot of turmoil,” Jones said. “And geothermal does not require global supply chains the way that intermittent energy and fossil fuels are impacted by global supply chains.”

Jones added geothermal enjoys support in the political space because it is an “everywhere” technology.

“Different sides of the political spectrum see and appreciate geothermal for the different attributes that it provides.”

Like other projects, geothermal faces the challenges of federal permitting. On average, Jones said it takes about seven years of environmental reviews for a developer to receive a permit."

“Geothermal doesn’t have a technology problem. It has a policy problem, and it’s a mature technology that’s been around for 100 years, more than 100 years. Once we address those policy challenges, the geothermal industry can take off in the United States.”

https://www.deseret.com/utah/2025/04/19/utah-geothermal-parcels-sale-nets-millions-for-potential-development/

In addition to the "high temperature" geothermal, there is also the ground source heating and cooling which has some advantages in some areas of the country. Not all areas are geologically suitable (rocky, for instance) as the cost of drilling the vertical wells, or laying a out a horizontal field is cost prohibitive.

If I were to be doing new construction, ground source heat pump would definitely be on the list for cost analysis.

"...Geothermal energy has a lower environmental impact ...."

That is likely true in the near term and longer term if adoption is not extremely widespread.

The geomagnetic field keeps our atmosphere on our planet. Without it, life (especially human life) will have a tough time continuing.

The geomagnetic field is a product of connective motion of the liquid outer core. Significant widespread adoption of Geothermal to meet a large portion of the world's needed power, will result in the core cooling more rapidly and the liquid portion shrinking more quickly.

How much heat can be rremoved without destabilizing the geodynamo and thereby the geomagnetic field? I don't know and I doubt experts in the field have a high degree of confidence in estimates (if there are well researched estimates).

Given our limited understanding of the geodynamo and AFAIK, the inability of anyone create a functioning model to demonstrate the phenomena, it seems like a significant investment in understanding would be prerequisite to any significant investment in widespread adoption of geothermal.

Well first of all the Earth's geomagnetic field does periodically weaken when the Earth's polarity switches, and no known catastrophic results occurred...

• Natural Fluctuations: The Earth's magnetic field is not static; it fluctuates over time, both in intensity and direction. It has also reversed its polarity many times throughout Earth's history.
• Reversal Process: During a reversal, the field weakens considerably as the magnetic poles shift, leading to a more complex and unstable magnetic field. This weakening phase can last for hundreds to thousands of years.
• No Catastrophic Effects in the Past: While a weakened field during a reversal could have significant short-term impacts, there is no strong evidence of major mass extinctions or other large-scale catastrophic events directly linked to past reversals.
• Current Situation: The Earth's magnetic field is currently weakening, but not at a rate that indicates an imminent reversal or catastrophic event.
• ...and no geothermal can not reduce the Earth's core temperature, it harnesses the heat radiating from the core, so that heat is destined to be irradiated from the planet anyway...
• ...and the amount of heat contained in the Earth's interior is well beyond anything we could influence.. ...
• "No, the use of geothermal energy does not significantly accelerate the cooling of the Earth's core. The core is extremely hot and radiates a vast amount of energy, far more than humans can extract through geothermal technologies. The amount of heat extracted by geothermal energy is negligible compared to the core's heat output.
• Heat transfer from core: .Opens in new tab The core's heat is constantly radiating outward, warming the Earth's crust and mantle.
• Human impact is negligible: .Opens in new tab The amount of energy humans extract through geothermal is very small compared to the core's natural heat output. Even if humanity used geothermal energy extensively, it wouldn't significantly affect the core's temperature.
• Core's cooling is a natural process: .Opens in new tab The Earth's core is naturally cooling down over geological time scales due to heat radiating into space.

..." The Earth has an internal heat content of 10^31 joules (3·10^15 TWh), approximately 100 billion times the 2010 worldwide annual energy consumption."....

https://www.reddit.com/r/AskScienceDiscussion/comments/mmqubp/can_extensive_use_of_deep_geothermal_heat/

'No know catastrophic events' for periodic weakening and reversals. Sure, temporary weakening and reversal probably results in some atmosphere loss and temporary limited increase in background radiation, but nothing catastrophic on a geologic timescale.

Consider Mars. From what we can surmise it once held a far more significant atmosphere than it does now. What is the likely explanation for the loss of atmosphere?

How close are we currently? How much heat loss will result in collapse?

Seems like having some certainty about answers would be important given what is at stake.

I think the retention of gases is largely governed by the mass of the planet, Mars seems to be too small to retain gases forming a thick atmosphere, much like the Moon...so if I were to guess I would say Mars never accumulated enough Mass to have an earth like atmosphere...Now if it were to be bombarded with asteroids for a time, it seems possible it could accumulate more mass and could then retain a decent atmosphere....but that seems a tricky proposition...

https://nssdc.gsfc.nasa.gov/planetary/factsheet/

Venus seems to be closest to Earth in mass...but the composition is vastly different...

..."Venus and Earth have vastly different atmospheres. Venus' atmosphere is overwhelmingly dominated by carbon dioxide, making it 93 times denser than Earth's. Earth's atmosphere, on the other hand, is primarily composed of nitrogen and oxygen. The pressure on Venus' surface is about 92 times that of Earth's at sea level, creating a crushing environment. "...

https://sci.esa.int/web/venus-express/-/34067-venus-vs-earth#:~:text=Venus%20has%20no%20surface%20water,K%20(477%20%C2%B0C).

Mars has an atmosphere. It's much thinner than the Earth's atmosphere, but still an atmosphere. We even flew the first extraterrestrial aircraft, Ingenuity, using that atmosphere. {Don't you read your links?}

Some even consider the Moon to have an atmosphere, but only an exosphere. It is plausible, but yet to be detected, that larger asteroids have an exosphere.

I don't think the plume from a comet is considered either an atmosphere or an exosphere, but that might be debated in the halls of planetary sciences.

Certainly the design of the ingenuity helicopter deserves a tip of the hat, very impressive to design and build...

...."The lower gravity of Mars (about a third of Earth's) only partially offsets the thinness of the 95% carbon dioxide atmosphere of Mars,^[66] making it much harder for an aircraft to generate adequate lift. The planet's atmospheric density is about 1⁄100 that of Earth's at sea level, or about the same as at 27,000 m (87,000 ft), an altitude never reached by existing helicopters. This density reduces even more in Martian winters. To keep Ingenuity aloft, its specially shaped blades of enlarged size must rotate between 2400 and 2900 rpm, or about 10 times faster than what is needed on Earth".... with a 4 ft wingspan I wonder what the blade tip speed would be at 2900 rpm....bonus question

https://en.wikipedia.org/wiki/Ingenuity_(helicopter)

Venus's dense atmosphere and slow rotation (long days/nights) makes the atmosphere much easier to maintain.

Venus, without an appreciable geomagnetic field, does not hold onto gasses as light at N2 and O2. CO2, and Sulfuric acid are much heavier and make gravity alone sufficient...

Unfortunately we breathe lighter gasses and thus need the geomagnetic field not only for protecting us from various types of high energy radiation, but also to keep our light gas breathing preferences satiated.

BTW, Mars certainly appears to have formerly had sufficient atmosphere to keep liquids flowing and eroding the surface...probably before it cooled too much and lost its protective geomagnetic field.

Even if you don't believe it has anything to do with keeping our atmosphere, shielding us from high energy charged particles is critical.

Well the Earth's core heat is constantly being generated, so what we could use is replenished by natural forces...

...."The Earth's core produces heat through several mechanisms: radioactive decay, primordial heat from Earth's formation, and frictional heating from the movement of denser material towards the center. Radioactive decay of elements like uranium, thorium, and potassium in the core and mantle releases energy in the form of heat. Primordial heat is leftover from when the Earth formed, and frictional heating occurs as denser material sinks towards the core"...

The answer to the bonus question is 169,759 MPH.
4` rotor diameter is for calculation purpose calculated at 0,5 m. Radius
Circumference using PI = 1.57m
Rpm 2900
Distance travelled in 1 sec. 75.92m
Distance travelled in one minute = 75.92 x 60 = 4555 m
Distance travelled in one hour 4555 x 60 = 273312 m

Convert to mph 273312 / 1.61 = 169759 mph

I get around 370 m/s or 828 mph....that's zoomin'...!!! no, that doesn't sound right....

https://hevvypumps.com/what-exactly-is-an-impellers-tip-speed-and-how-do-you-calculate-it/

370 m/s x 3600 = 1.332.000 meters /hour thats 827.329 mph !! not quite right, me thinks..
Have just realised I had a mistake in my calculation.. so rethink 4 ft is roughly 1 meter so diameter 1 meter

x Pi =3.14 Circumference

x 2900 rpm = 9106 meters per minute
9106 / 60 = 151,77 meters per second
151.77m x 3600 = 546360 meters per hour
546360 / 1.61 = 339.354 MPH.

The wingspan is 4 feet, that times Pi is about 12 feet circumference...if you have 2900 revolutions per minute, that's about 48 revolutions per second or about 580 feet per second...if we times that by 60 to get feet per minute travelled we get 34,800 if we then divide that by 5,280 feet(1 mile) we get around 6.6 miles per minute...if we then times that by 60 to get mph we get around 395 mph....that sounds about right...

All Blade Tip speeds are calculated in m/s, but your calculation is near emough as you used Imperial measurements instead of metric.
4 ft. is roughly 1 meter (39.4 inches) so diameter 1 meter

x Pi =3.14 m Circumference

x 2900 rpm = 9106 meters per minute
9106 / 60 = 151,77 meters per second
151.77m x 3600 = 546360 meters per hour
546360 / 1000 = 546.360 km/h
546,36 kms / 1.61 = 339,35 MPH.

4ft = 1.22 meters...your margin of error is too great...

Too great for what? It is perfect for a BS session on a dying engineering blog.

You pointed out the obvious, unfortunately SE’s post was the remaining reason on whats keeping this blog on life support.