The members and officers of the AEA are geographically distributed at universities around the country, and their biannual conference moves around from city to city, but their Secretary–Treasurer is a professor at Vanderbilt (the previous Secretary–Treasurer was also a professor at Vanderbilt) and they have a permanent office in Nashville.
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 impression is that Saratoga Springs is just where their first conference was. I don’t think they ever had an office there. I couldn't figure out in a brief search if they had a prior permanent office before the one in Nashville.
That is in fact what I was trying to say about Sarasota Springs ;-)
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.
Drilling through more conventional formations (oil or gas) that didn't need fracking. Particularly on formations with large, flat layers it could greatly reduce the number of wells needed, vs. vertical drilling. It's also very useful for offshore drilling.
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.
Construction projects frequently use it on a small scale when excavation or disturbing existing infrastructure isn’t possible. For example, you need to lay an electric cable for a new development across a road and you can’t shut down the road, so you drill horizontally underneath it and run the cable through.
There isn’t such a clear line between those two as going slightly deeper for slightly warmer rock makes a big difference when you mostly want heat from that heat pump.
~1c per 40m may not sound like much, but it quickly adds up over 50 years.
There was a story in the NY Times six months ago about colleges in the US going with geothermal. Many are putting in shallow geothermal to be used with heat pumps (depth ~900 feet), but Cornell has also been looking at true geothermal with an exploratory well to nearly 10,000 feet (bottom temperature was 82 C).
This is more people just casually conflating two separate terms: geothermal and ground-source. Pretty frustrating since it is right there in the name of each, ground-source heat pumps are near-surface and basically leveraging the annual average air temperature while geothermal resources are leveraging higher temperatures much deeper in the earth.
My dad had a "geothermal" heat pump installed back in the late 90s; that was the term that was commonly used at the time. The US Department of Energy uses that term even today: https://www.energy.gov/energysaver/geothermal-heat-pumps
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.
It's also correct. They exploit heat (thermos) from the Earth (geos). A geothermal power plant and a geothermal heat pump differ in many particulars, but not in the meaning of the adjective they share in common.
"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)."
My old University has been powered by Geothermal for 11 years now, and they produce quite a bit more than they need, so they sell excess to the hospital next door.
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..
Especially since this is a PPA, so it's basically a crowdfunded power plant. People will buy shares in each well to get it constructed and use the energy produced to offset their power bill.
Usually you see these with solar projects, but I don't see any reason a geo plant can't operate on the same principle.
I think of geothermal the same way I think of tidal power - seemingly renewable but not really. Harnessing tides dampens the lunar oscillations surprisingly fast (as discussed here: https://news.ycombinator.com/item?id=37383283).
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.
It's sustainable in the short term (for a very long definitoon of short term) though, which is what really matters wrt migrating off of fossil fuels. We could pull many times humanity's energy consumption from the earth for a century and it would still be a drop in the bucket.
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.
Yeah the scale of thermal energy contained in the earth makes this fear (prematurely cooling the earth) irrelevant. The entire global consumption of energy is less than 2% of earth's thermal heat flow from the core.
Whoops, thanks for the correction. I was looking at end-user electricity consumption so it didn't include all the losses involved.
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.
If this is something we actually need to be worried about, why not rant here? I think most people are pretty far from convinced that literally cooling off the earth through geothermal is a possibility we need to be taking seriously.
Drilling 125 wells for 400MW of power seems like a pretty poor return. Although it's hard to tell as the article doesn't go into much detail around the depth of those wells.
Unless the price of energy goes up globally because of political/commercial instability created by climate change ?
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 ?
Lots of oil rigs work off-grid, and refineries have historically also operated off grid, though nowadays they buy or sell electricity as needed, depending on load and price.
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.
Hence the reason this hasn't taken off yet. Add in the geographical requirements of heat close enough to the surface and costs go up higher. Because it's baseload power, its ouput has higher value than intermittent sources per mwh produced.
> Solar ? Short lifespan, land occupation, requires mining
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.
How many gas wells are punched for every gas turbine? Apparently there are about 500GW of natural gas power stations in America and 90000 producing gas wells, and 40% of that is for electric power, so 15MW per hole in the ground.
That is an excellent comparison. And with the assumption that geothermal wells can last longer (the wells for my geothermal HVAC system were rated 50+ years, although I presume my wells and the types of wells needed for a 400MW plant are far different) then this is actually pretty decent.
> Drilling 125 wells for 400MW of power seems like a pretty poor return.
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.
Hm... some articles are saying "largest new" and others just "largest". I don't think it's the largest but maybe it depends on what we mean by "geothermal development".
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.
The editing on this piece is ... sloppy in the extreme:
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.
Genuine question: does "cooling" the center of the Earth via geothermal power plants have any sort of ramifications?
If we converted to using 100% geothermal power, what kinds of effects would that have on the Earth's core?
When I looked into this the numbers suggested that energy-wise we'd be extracting a drop in the bucket. There are concerns for local effects though (e.g. earthquakes).
Geothermal concentrates the thermal flux to the geothermal energy site.
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.
Emitting heat technically. Imagine rocks warmed by a fire or those in a sauna, they cool off very, very slowly. At earths core is a giant chunk of super compressed and super heated lead. I don't recall if the core is the size of the moon, but you could imagine a solid ball of lead for your sauna that is the size of the moon and so hot it would melt if it were not under extreme pressure.
There's a nearly-negligible amount of heat being created from simple radioactive decay, but essentially all of the heat is just leftover from the formation of the planet.
Which is just nuts to think about. The core is that hot and it has been for billions of years. Incredible.
I had no idea about the Puna geothermal plant! I'll read up on it!
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. :(
Geothermal doesn't cool the center of the Earth; it cools the crust around the wells. The effect farther away is miniscule on any reasonable timescale. Think of it as mining crust heat.
Roughly equivalent to the rise in sea level because of displacement from offshore oil drilling platforms and wind turbines. Which is to say, immeasurable.
We are operating on such a tiny sliver of the crust that worries about the core temperature are many orders of magnitude away from being a problem.
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.
If geothermal energy were to be utilized at every opportunity, could all the thermal energy being pumped out of the ground create a new kind of environmental crisis? Or is there so much energy down there that mankind as a whole would never be able to make a non-negligible change to the earth in that way?
Similar to how if we came up with some clean fusion and then multiplied all our energy use 10, 1000, 10,000-fold, then at what point would we be actually heating up the atmosphere directly (instead of indirectly via green house gasses)? I'd like to see the math on this too.
No. It will be a slightly warm damp rock regardless of what we do, until in the distant future the nearby star either destroys it or goes out leaving it to gradually cool down.
I was on my way to Hawaii on vacation and we flew directly over that. I wondered what the heck that was out there in the middle of nowhere but couldn't find anything online. And, now, here it is!
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[ 4.2 ms ] story [ 128 ms ] threadThis 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...
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://kslnewsradio.com/2113554/largest-geothermal-energy-d...
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://www.osti.gov/etdeweb/servlets/purl/895238
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-...
https://en.wikipedia.org/wiki/Watt#Terawatt
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.
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.
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.
<https://en.wikipedia.org/wiki/The_Geysers>
"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-...
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.
https://fervoenergy.com/fervo-energy-announces-320-mw-power-...