Largest Geothermal Development in America Taking Shape in Utah
mymodernmet.com
mymodernmet.com
The article quotes 400 MW and 125 wells, but according to a Wikipedia list [0] there are at least two geothermal complexes in the U.S. that produce more power than that and at least one that has over 350 wells [1] that appears to not only be the largest geothermal complex in the country, but in the whole world.
[0] https://en.wikipedia.org/wiki/List_of_geothermal_power_stati... [1] https://en.wikipedia.org/wiki/The_Geysers
In a victory for the development, one of the nation’s largest utility companies, Southern California Edison, has agreed to purchase electricity from the development. The 15-year agreement will power the equivalent of 350,000 and begin when the development's first part is operational in 2026.
350,000 what?
(The answer is all but certainly "homes", which draw about 1.2 kW each, which puts this plant at about 400 MW output ... as is noted three 'graphs further down the article. Compare against a typical large nuclear power plant at 1--2 GW output per reactor.)
As you note there's also the Geysers plant in northern California (near Healdsburg) which has a nameplate capacity of ~1.6 GW, and a 53% capacity factor (that is, it's operational about half the time. Which would make the Met's article wrong on this point as well.
"World’s largest geothermal PPAs highlight increasing utility demand for clean, reliable next-generation geothermal energy"
PPAs are power purchase agreements
https://fervoenergy.com/fervo-energy-announces-320-mw-power-...
1. Extracting heat energy from magma within the earth via steam turbines. This is what is mentioned in the article.
2. Using the ground as a sort of infinite thermodynamic reservoir via a heat pump working as the same principle as a refrigerator.
~1c per 40m may not sound like much, but it quickly adds up over 50 years.
https://www.nytimes.com/2024/01/23/climate/geoexchange-clima... (may be paywalled)
Not sure where you're hearing the term "ground-source heat pump" in common usage, but it certainly has not filtered out into common parlance.
"The system comprises an injection and production well pair drilled within a high-temperature, hard-rock geothermal formation. According to Fervo, the lateral sections of the wells were drilled leveraging technology innovations from the unconventional oil and gas industry with a 9 7/8-inch hole size, completed with 7-inch casing, and extended about 3,250 feet horizontally. They reach a maximum measured temperature of 376F (191C)."
https://www.powermag.com/innovative-enhanced-geothermal-syst...
It's an umbrella term; it covers methods that leverage temperature differences between the ground and the air to exchange energy.
In FL, 64° aquifer water is used for cooling structures over 15k²ft. I worked on control systems for those.
https://www.americangeosciences.org/critical-issues/maps/geo...
There are other geothermal wells on campus (not as deep or hot) just for hot water, that are used to flow in pipes directly under large staircases (campus is built on a hill) and sidewalks to keep them clear in winter, and are also used with large heat pumps to heat and cool all buildings on campus. Those have been used since the 60's..
Warning, PDF's
https://chptap.ornl.gov/profile/174/OIT_ORC-Project_Profile....
https://fervoenergy.com/fervo-energy-announces-320-mw-power-...
We drill a few thousand meters into the crust. There's several thousand kilometers of earth below that.
What happens in practice is that such sites end up being rate-limited by either the thermal flux of the surrounding rock, in the case of dry holes which are bored and take out heat directly, or by depleting the groundwater and/or hydrothermal reservoir which feeds a "wet" geothermal project (as with California's Geysers).
Dry holes end up having a limited effective life of a few decades, based on what I've seen, after which there's insufficient thermal energy to drive electrical generation (though it may be suitable for other lower-grade heating applications). Wet holes vary in response depending on how rapidly groundwater is replenished. I believe that the Geyers has dried up numerous wells. In places with ample water infiltration (e.g., near coastlines or in wet climates), I speculate that intrusion of fresh cold water might cool the geothermal reservoir somewhat.
But the source heat, which is radiating from the Earth's core though the mantle and crust, has an effectively fixed flux. There's only so much heat radiating outwards, and a few localised pinpricks and steam generators won't effect that measurably. Volcanoes are far larger and similarly have little overall effect.
The heat is coming out one way or another. It already traveled 6500 km to the surface unaided, we're just helping it up the last 1 km or so. Frankly, I'd be interested if the core would notice an effect from the removal of the Earth's crust in it's entirety. My money is on "no for any human-relavant-timescale."
For reference, the interior of the Earth works out to about 50 TW of heat. Today, humans consume about 20 TW. The Sun delivers 173000 TW.
https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget
Which is just nuts to think about. The core is that hot and it has been for billions of years. Incredible.
So no, not 'minimal'.
My "minimal" remark was intended as a response to the question of our effect on the Earth's core; I should have made that more clear. I'm sure we'll uncover all manner of consequences to the upper crust.
Having read into your comment a bit, the USGS doesn't agree with you. :(
https://pubs.usgs.gov/of/2020/1017/ofr20201017.pdf
https://earthscience.stackexchange.com/questions/14259/did-t...
But there is an awful lot of energy there so I don't think we need worry for a few million years.
However, there are some side effects. Iceland heavily invested in geothermal power plants and as a result their natural geysers are dying out. This is also why the US doesn't run geothermal power plants in the Yellowstone caldera, because the danger to the tourism industry outweighs the potential gains, at least for now.
This is an outlier amongst US professional science associations:
- Physics: APS, College Park, MD
- Astronomy: AAS, Washington, DC
- Chemistry: ACS, Washington, DC
- Biology: ASBMB, Rockville, MD; ASCB, Bethesda, MD; ESA, Washington, DC; AIbS, Washington, DC.
- Psychology: APA, Washington, DC
- Sociology: ASA, Washington, DC.
- Political Science: APSA, Washington, DC.
- Economics: AEA, Nashville, TN.
(That last ... surprised me.)
I'm just ... curious as to how the AEA came to be at Vanderbilt / Nashville, and if that's always been the case. I've searched a bit on the history w/o success.
AEA was founded in Saratoga Springs, NY, by amongst others Richard T. Ely (interesting history), though I don't see any obvious Tennessee connection by him, or cofounders Katharine Coman (Wellesley College) or Edwin R.A. Seligman (Columbia University).
My next tack is to track down old copies of AEA journals (AER, J. Ec. Lit., J. Ec. Persp.) and see where they're published from or where they otherwise indicate location.
Measurement-while-drilling (where instruments in the drill string sense the surrounding formation, allowing it to follow ups and downs in the layers) is quite a technical accomplishment. Think about the problem of getting data back to the surface.
0 - https://en.m.wikipedia.org/wiki/Directional_drilling
1 - https://m.youtube.com/watch?v=a5d9BrLN5K4&pp=ygUddGhlcmUgd2l...
https://kslnewsradio.com/2113554/largest-geothermal-energy-d...
If we knew something that had all the perks of oil and none of the disadvantages, we would be all hooked on it. All clean energy are trade-off's compared to oil.
Solar ? Short lifespan, land occupation, requires mining, the sun does not always shine, not much energy so you need a lot Wind ? Lifespan, much skill to build and to maintain, the wind does not always blow, not much energy so you need a lot Nuclear ? Big upfront cost, need skilled workforce to build and maintain Geothermal ? Big cost for not so much energy ?
All of those need a good grid too
So does oil.
What oil actually depends on is a transportation network, and aside from trains and pipelines, that's pretty flexible too.
It was not to detract from the need for new and renewable sources of power, but rather surprise at how little power you get from each well, and the cost of drilling each of them.
Almost everyone I know of who has had solar panels for a long time reports they last a lot longer than promised. And even if some part breaks, it can be replaced. You don’t need to repeat the whole time and expense of acquiring the land, building the facility, grid interconnect and permitting. This means humanity gets a dividend in energy over the very long term, which balances favorably against the upfront cost.
The issue of intermittency is more valid. It can be mitigated with battery storage, which has its own cost and downsides, but the chemistries are advancing rapidly, so I think the future is bright for energy abundance.
That's 400 MW of 24/7 baseload power. Forever, for free.
The nuclear power lobby is scared shitless of geothermal generation becoming not just viable but proven, because "cheap baseload" is just about the one thing that NPPs are actually pretty damn good at.
Usually you see these with solar projects, but I don't see any reason a geo plant can't operate on the same principle.
With geothermal, yes there is a huge reservoir of potential energy but speeding up the extraction of this energy is absolutely a terrible idea long term. I'm not gonna rant here, but look at what happened to Mars (only slightly smaller than earth) when the core cooled and the dynamo shut down.
Now, some of these hot spots might not be renewable (in the sense that we drain too much ehat from them and they don't have sufficient heat flux to sustain as much extraction as might seem), but I don't think there's any risk of cooling the core.
See e.g., https://www.wired.com/story/how-long-will-earths-geothermal-...
That's staggering at first glance. So much energy!
But then, I wonder how much it would really matter if we were harvesting that energy to move objects around on earth and turn on LEDs vs letting it dissipate into space. So I'm still skeptical of the concern.