Why geothermal isn't ubiquitous and how it might get that way
austinvernon.eth.link
austinvernon.eth.link
https://www.ucsusa.org/resources/environmental-impacts-geoth...
The takeaway
> Enhanced geothermal systems, which require energy to drill and pump water into hot rock reservoirs, have life-cycle global warming emission of approximately 0.2 pounds of carbon dioxide equivalent per kilowatt-hour [11].
> To put this into context, estimates of life-cycle global warming emissions for natural gas generated electricity are between 0.6 and 2 pounds of carbon dioxide equivalent per kilowatt-hour and estimates for coal-generated electricity are 1.4 and 3.6 pounds of carbon dioxide equivalent per kilowatt-hour.
Nothing is really truly zero carbon currently. Solar has manufacturing and maintenance. Nuclear has construction, mining, refinement, containment, etc. It's nice to see the full lifecycle being looked at.
We can't pretend that something essential for the process doesn't matter because we do a classification handwaving. It all counts
We can only state things in terms of stuff which currently exists. The future will yield different results because new techniques and technologies will come along. But we can't rely on or predict them.
There's a lot of "pons and fleischmanning" when talking about future energy use - mass scale geo-engineering or sucking carbon out of the atmosphere technology, it has to be avoided. The technologies don't exist yet. We have to use real-world stuff.
Using current reality for future projections is inherently defective because of the innovation factor and routinely leads to bad predictions (such as peak oil[1]), but it's the only reality we have and is sadly as good as we're going to get. Anything else (such as say next-gen nuclear) has to be regarded as a fiction in the calculations until it actually exists.
It's messy, sloppy, and requires a large trashcan but the alternative is to get to results that rely on things that literally do not actually exist. Kinda like how the people planning Operation Downfall (the land invasion of japan during ww2) weren't told about all the other things in the works (backroom deal to get Russia to declare war on Japan and the Manhattan project), they had to assume those things would continue to not happen.
[1] - The Hubbert peak was essentially that the amount of energy to extract and refine oil would surpass the energy from the oil and thus make it unsustainable so the operations for oil extraction would cease. New techniques have been developed (such as fracking) which have changed this math, but in 1956, using 1956 knowledge, this was the best prediction possible. It's somewhat Malthusian - who was also as "correct as possible" with the best science that 1798 had to offer. He couldn't factor in, say, the Haber–Bosch process from 112 years in the future in his food growth computations.
but are certain that at least one of these fictitious scenarios will come into being. We just have no certainty as to which.
I think a healthier futuristic perspective would be one that considers only some percentage of problems will be solved through innovation, at least in the near term. That way we accept we still could be screwed and need to work harder!
We're already well past the point where if we just stopped emitting we will be ok. We now need carbon capture as part of the solution and thus far nothing has panned out. Nor is there much political will to actually push for solutions. They're just seen as pure cost that will make your country less competitive so nobody wants to be the only country who goes for "truth" in this prisoner's dilemma.
Global warming wasn't as important as a nuclear winter.
Embarrassing to use fossil fuels? In front of who? some future self who judges you? Wait till you see next decades' problems.
We did mostly fix the Ozone hole though, albeit it is still an ongoing process.
1) China's heavy exports meaning that transporting bulk goods TO China was practically free, because the ships were making the trip while empty anyway
2) China's manufacturing industry growing so fast that they simply, literally could not get enough plastic
3) Dirt-cheap labor costs in some parts of China enabling labor-intensive recycling on razor thin margins
4) Corruption and a disregard for the true costs of environmental damage making waste dumping look far more profitable than it actually was.
AIUI these have disappeared recently, due to China's economic growth, and shift from exports to selling domestically, and their environmental damage starting to seriously catch up with them, all of which resulted in them no longer accepting plastic.
What they banned was people pretending to send recyclable plastic but really just sending them any old junk.
https://en.m.wikipedia.org/wiki/Operation_National_Sword
Text from their official notification:
> Objective and rationale, including the nature of urgent problems where applicable: The reasons for urgent measure: According to the Special Actions of Strengthening the Supervision and Strictly Striking of Illegal "Foreign Garbage" by the General Administration of Customs of China, Ministry of Environmental Protection of China, Ministry of Public Security of China and General Administration of Quality Supervision, Inspection and Quarantine of China, as well as the Special Actions of Striking of the Illegal Actions of Imported Solid Waste Processing and Utilizing Sectors by Ministry of Environmental Protection of China, we found that large amounts of dirty wastes or even hazardous wastes are mixed in the solid waste that can be used as raw materials. This polluted China's environment seriously. To protect China's environmental interests and people's health, we urgently adjust the imported solid wastes list, and forbid the import of solid wastes that are highly polluted. Protection of human health or safety; Protection of animal or plant life or health; Protection of the environment.
Talking, but never actually doing.
If there were some large scale way to scrub carbon out of the atmosphere then the market could work, but in their current state they are a joke.
We don't need to wait for that to set up an impactful system. At the simplest, have a serious tax and dump a bunch of the resulting money into research grants and a big reverse auction for capture.
In that context the lifecycle emissions stats are less useful because the calculation assumes a rate of indirect emissions (due to construction, mining, refinement, containment, etc.) based on the incumbent power generation tech.
In other words, if geothermal power was more ubiquitous, then the indirect emissions for a new geothermal project would be lower.
I'm being a bit pedantic, but I think its an important point: The life-cycle carbon cost of renewables isn't a fact about renewables. It's a fact about our current energy production mix, which renewables themselves will change over time.
Sure but we are talking about right now. Things will eventually be swapped out. That's a different conversation though, it's an advocacy and not a descriptive one.
People tend to use things that are marginally adequate way longer than anyone intended. For instance, the ancient Roman gravity dam of Proserpina is still doing its job.
Even if we had say a sleek $1,000 self driving solar car that never needs charging and goes for a million miles without maintenance, there's no guaranteed adoption curve, production capacity, distribution and logistic timeline, consumer acceptance, these are all hard unknown realities regardless of how silvery the bullets are.
Decarbonization compounds. That means that "lifecycle emissions" analysis can end up being too pessimistic if you consider changes made in a vacuum. Electric cars require steel and electricity to make, so considered by themselves (while still definitely worth it) don't look as good as they do when you consider we will need to be decarbonizing steel and electricity as well.
Power plants need vehicles and steel as well, so decarbonizing transport and steel also reduces the lifecycle emissions of power plants!
I think people resist this type of thinking because of a different kind of magical thinking: a sort of anti-silver-bullet magic. They have the idea of fossil fuels as fundamental to civilization, like we can't actually get rid of them. But this isn't true. We can eliminate fossil fuel usage just fine.
We should consider fossil fuel as the seed corn. Instead of feeling bad that it takes fossil fuels to do the initial manufacture of geothermal (or whatever), consider it as simply priming the pump, as seed corn. There is no better use for fossil fuels than assisting in manufacturing their total replacements.
As part of cement making, "The process of 'calcination' splits the material into calcium oxide and CO2."[1] About half a ton of CO2 is emitted per ton of cement.[2]
And with steel: "The prevailing process makes steel from iron ore — which is mostly iron oxide — by heating it with carbon; the process forms carbon dioxide as a byproduct. Production of a ton of steel generates almost two tons of CO2 emissions."[3]
Wind farms use a lot of concrete and steel; by some estimates, more than nuclear.[4] Of course, total emissions is still way less than fossil. Assuming normal lifespan, about 25 lbs of material per MWh[5], so (very) roughly that much CO2. By comparison, a coal plant emits over 2000 lbs CO2 per MWh. [6]
[1] https://www.bbc.com/news/science-environment-46455844
[2] https://www.linkedin.com/pulse/co2-emission-from-cement-indu...
[3] https://news.mit.edu/2013/steel-without-greenhouse-gas-emiss...
[4] https://thebreakthrough.org/issues/energy/nuclear-has-one-of...
[5] https://www.freeingenergy.com/math/wind-turbine-weight-pound...
[6] https://www.epa.gov/sites/production/files/2020-12/documents...
Trying to make every arbitrarily delimited activity carbon neutral on its own sounds like a cult hijacking AGW to me.
Here's essentially the problem you're laying out.
If I have a house run by solar power and walk to the store to buy fruit from 10,000 miles away to feed to my 5 children, my carbon costs are so astronomically high from the last two that the first two don't matter.
I agree! Absolutely!
But also, if transporting fruit 10,000 miles could be done with renewables that will zero that out.
If by the time the children are adults, significant delimited activity has transformed through say, better agricultural practices, more efficient appliances, better building design to that can regulate temperature better, all these small things, then the aggregate decreases
Stop having 5 kids and buying 10,000 mile away fruit, I'm with you. Sure.
But the point of this exercise is to make such things not so high cost so that the freedom to do these things, however much I personally disapprove of it, can be preserved.
That's one of the things the anti-climate change people don't get. They see the current transformations as a restriction of their liberties. No, it's a massive effort to preserve them. If we fail to transform society and cities start sinking into the sea, I assure you, forced sterilization, meat consumption bans, bans on private car ownership, local only food by law, a ban on air travel, it'll all be on the table. We all saw how quickly the shoe dropped on covid last march; from busy streets to boarded up ghost towns in about 2 weeks. We didn't heed the warnings to prepare and here we are still living with the consequences.
Let's stay on top of this one.
My late grandpa had a small plot of land where he grew tomatoes and other vegetables. Since he died 12 years ago nobody does anything to that land cause he lived far from the rest of the family. It's a small forest now.
Not cutting trees for new farming land and leaving the space is the problematic part. And more kids is kinda at odds with this.
BTW what you're actually doing by planting a tree is burning carbon to move an already existing plant from one place to another.
That is true (unless you're actually planting seeds), but generally the idea is that another tree will grow where you took it from, so the end result is more trees.
BTW one of the weirdest examples of "patriarchy" is the preference of city planners to plant only male trees (because they generate less "junk"). Which reduces the amount of new trees growing in and near cities significantly.
Second, you can choose trees which are particularly good at sequestering carbon for long periods.
Humans are already animals that act as “ecosystem engineers” (like beavers or trees). https://en.wikipedia.org/wiki/Ecosystem_engineer
We just haven’t historically been very good at it (ie we’ve often historically reduced ecological diversity instead of facilitating it). I think we can do much better, and there are many examples of humans who HAVE done a great job at it (for instance, the man who planted a forest on an island in India). https://m.youtube.com/watch?v=HkZDSqyE1do
Do you think the planet would be better off if everything else was the same but his parents had decided not to have him? So this is why I think we can’t apply a broad average of human footprint to whether someone should decide to have kids or not. Instilling values, such as being a net-positive to the environment and the value of choosing to live a net-carbon-negative life (and support continued climate action), can be more important than just the marginal impact of not having kids at all.
Also, negative-sum thinking ends up in a pretty dark place pretty fast if brought to its logical conclusion.
And it seems pretty obvious what the long term result would be if all climate-conscious people had no kids but folks who don’t give a crap about climate action raise lots of children.
I would imagine that we can actually do a lot to accelerate the process of trees spreading over an area. And even a small speed-up compounds over time.
And of course some species are cloned because it faster and cheaper, so then female saplings aren't a problem. You clone what has higher demand.
> I would imagine that we can actually do a lot to accelerate the process of trees spreading over an area.
Yes I was a little facetious. I don't actually plan to persuade people not to have kids or not to do gardening. But when I see people gathering millions of dollars to use drones to plant trees I can't help but think it's focusing on the wrong (but cool) part of the problem.
Human civilization, as it becomes more reliant on solar power, essentially becomes photosynthetic. Already, sustainable harvesting of trees to make long-lived structures can sequester more carbon than a tree does as it decomposes on the forest floor at the end of its life (emitted CO2 and a bunch of methane, which is worse). But we can also do “photosynthesis” more directly by using photovoltaics to produce hydrocarbons from direct captured CO2 and water. In fact, going back to the space meme, this is already done on the International Space Station as a side effect of the life support system. Water is split into oxygen (for the crew) and hydrogen. The hydrogen was originally just vented to space along with CO2 (expelled by the crew) captured from the cabin air, but they realized they could combine the hydrogen with the CO2 and recover the oxygen in the form of water, with the hydrocarbon methane as the byproduct. The methane is vented to space normally, but then they realized they could use the methane and reform it into polyethylene and hydrogen (which can be recycled to capture more oxygen form CO2). The polyethylene could be used in the 3D printers on the space station to produce structures. (NASA hasn’t accomplished this methane to polyethylene goal, yet, although methane-to-polyethylene/polypropylene is done on Earth via methane to methanol, then methanol to olefins). This is, essentially, a synthetic kind of photosynthesis. NASA funded SBIR grants to try to demonstrate this process. And there’s no reason you can’t make any kind of hydrocarbon this way from water and CO2 (hydrogen and CO—which can be made from CO2, as Perseverance demonstrated—are synthesis gases which can be used via the Fischer-Tropsch process to produce any hydrocarbon).
In this way, as the mass of a photovoltaic-centric human civilization (buildings and infrastructure and machines) in the form of carbon fiber and wood and resins grows, it is sequestering carbon in its own structure, just like a tree does. So humans (with their houses and buildings, etc) can, in fact, become carbon negative as we transition to clean energy including for utilizing synthesized (or natural) hydrocarbons (or sustainably harvested wood) for structural materials.
>I agree! Absolutely!
No, you're not agreeing with me. You're talking about a family unit as if the net balance matters. That's exactly what I was saying makes no sense.
Nothing has to balance except the whole world. Not people, or families, or industries, or companies, or countries.
I don't know if there is a name for the fallacy, but there's this mental short circuit I think I observe, where people want to compose the parts of something to get a quality of the whole, and it doesn't work.
If you want a blue city, then the way you get it is by making all the parts of the city blue. And recursively, every part of the parts can be painted blue.
But if you want a profitable company you do not get it by making every part profitable. That's stupid and destructive and often people seem to consider it obviously idiotic when it is tried.
Carbon emissions are like the latter, not the former.
In equations:
blue + blue = blue
but
5 + 5 ≠ 5
Essentially their highest aspirations were to avoid global war and assist in ongoing nation scale catastrophes, which they have done ok at.
They were pretty cynical about systems that essentially COP is structured under as being ineffective. Which it has been, closing in on year 30 of ineffectiveness.
This problem of global governance for issues like this is still fundamentally unsolved.
It has to work more like slavery, colonialism and chemical weapons; humanity eventually collectively found the idea reprehensible and we are mostly in agreement on the right direction. This is the only method that has worked so far.
You can have inspectors and enforcements but unless the people of the country also find the thing to be dishonerable, their loyalty to their leaders (political, bosses, wealthy, whatever) is the more important loyalty.
They'll stop shoveling coal into the furnace when the global police come by but then do it again after they leave. They have to want to stop intrinsically, not through a punitive threat. They have to be able to thrive and live well by not doing it too.
It's gotta be less work, easier, and pay better.
I mean look, I'm open to trying other things but they haven't been working. This method takes centuries, we still have prison and indentured labor which are effectively slavery, over 200 years later
We don't have that kind of time but also we don't have any other kind of solution
"I lost my keys in the dark, but I'm looking under the streetlight because that's where the light is".
I don't understand the frame of mind where you keep arguing about how you don't have a flashlight, I don't have a flashlight, we can't possibly wait until morning, etc. If you can't solve a problem, swapping it for some arbitrary thing you can solve is pointless.
Saying "it has to work" is the sort of thing people say in the movies. Something "has" to work because the script writer decided on it.
Coordinated global action may in fact be impossible. Some people think an effective world government would be a fate worse than unrestricted emissions.
I'm just saying it's the solution by definition. Again, because that's what "global" means.
>It has to work more like slavery, colonialism and chemical weapons
I don't know what I can say for a third time that I didn't say the first two and I feel like you are ignoring.
These are all things that compose like my analogy of painting things blue. If the people in a family did bad stuff, then their family did; if the families in a country did, then the country did, etc.
They are not things that compose via the summation of numbers corresponding to their parts. You don't add up a measure of colonialism produced with a measure of colonialism consumed elsewhere. There is no target threshold for colonialism or slavery or chemical weapons.
Not to mention, from what I read, all three things are very widespread to this day, so if they were like carbon dioxide emissions, it would be a pretty pessimistic sign anyway.
1. More efficient agriculture Cutting and clearing land for agriculture is generally destructive - so a) everyone becomes vegetarian, b) stop growing food in 2 dimensions c) grow more efficient food (broth and hydroponics)
2. more efficient transport of food Don't transport food thousands of miles, don't refrigerate it, don't fly it,
3. transport to move off carbon Stop flying, more EV.
4. reduce travel apart from flights and holidays (carbon tax) commuting is huge contributor- remote working will impact this
4. Building efficiency Insulation and ground source heat pumps and so on See also strongtowns - denser living is halley kore efficient t living
Anyone have any links to the numbers?
https://helioscsp.com/concentrated-solar-power-csp-and-indus...
Cement DOES emit CO2 during manufacture, but it also absorbs it during cure (which, granted, can take decades). That means you can potentially use it for direct air capture in a sort of indirect way. (i.e. you capture the CO2 emitted during calcination, when the CO2 is very concentrated and easy to capture, then the cement itself captures CO2 directly from the air during cure).
US Steel has started to look into hydrogen production, but hasn't built anything yet. [0]
Europe has some pilot projects for hydrogen-produced steel but nothing operational. [1]
We certainly should make that conversion, and also ensure that we use green hydrogen for it, but that's a big change and there won't be much economic incentive for it before we have a decent carbon price. "Renewable hydrogen-based iron production can become the least-cost supply option at a carbon dioxide (CO2) price of around United States dollars (USD) 67 per tonne," but "the hydrogen energy used would equal 1% of global primary energy supply." [2]
Carbon capture during cement production of course also lacks economic incentive until we have a carbon price, but I haven't found a specific price it would need.
[0] https://www.reuters.com/business/energy/us-steel-norways-equ...
[1] https://bellona.org/news/industrial-pollution/2021-05-hydrog...
[2] https://onlinelibrary.wiley.com/doi/full/10.1111/jiec.12997
DRI/HBI furnaces use a mixture of hydrogen and CO. So they already use hydrogen, but it comes from natural gas. However, this input mix of hydrogen and CO can be changed to be almost all hydrogen (almost CO can also be made electrolytically from CO2, as NASA just did with the Perseverance rover on Mars).
Parent is correct that it "all counts," but that doesn't mean it all resolves to the same thing over the long term.
For example, one of solar's key strength is the improvement curve that its on. Carbon, energy and dollar costs are improving. So in a sense, every Kw produced now reduces the costs of Kw produced in the future. Its valid an important to think of lifecycle costs currently, it's also not a full picture.
As an example burning trash for power gets relatively worse as other energy sources become carbon free, while recycling gets relatively better as the energy required becomes lower carbon and/or cost.
I doubt that any such analysis accounts (nor should it) for technological curves yielded by investing in one technology or another. There are limits to any one calculation.
"pounds per kilowatt-hour" has to be a strong contender for most ridiculous choice of units. One might almost use that as a joke.
Even "pounds per mechanical horsepower hours" would have been more sane.
Funny thing: in France, stats for wind energy include the cost of wiring, and cables are required to be buried. Stats for nuclear just ignore the wiring. I'm pro nuclear, but that always bugged me.
Or you can also recharge them during the summer, either with solar thermal panels, or on a small measure, by running your HVAC "backwards" (i.e. cooling your home and thus heating the wells)
https://www.wired.com/story/how-long-will-earths-geothermal-...
Considering our sun will explode in 5.5 billion years, that should be good enough.
The first hit on google for this phrase is .. this comment, so could you provide a less circular citation please? :)
I do understand that all heat is local, you cannot extract heat faster than it can flow to the point of extraction, which is dependent on the R value of the rock and whether you've drilled into a liquid area or not.
(I wonder if there are some oil fields that have high enough below-ground temperatures to be worth using for this? The drilling is done, a sunk cost, and the wells produce mostly dirty water)
https://www.quora.com/What-is-the-ground-temperature-at-the-...
https://www.cleanenergywire.org/news/germanys-geothermal-sec...
> Even though geothermal power is globally sustainable, extraction must still be monitored to avoid local depletion.[21] Over the course of decades, individual wells draw down local temperatures and water levels until a new equilibrium is reached with natural flows. The three oldest sites, at Larderello, Wairakei, and the Geysers have experienced reduced output because of local depletion. Heat and water, in uncertain proportions, were extracted faster than they were replenished. If production is reduced and water is reinjected, these wells could theoretically recover their full potential. Such mitigation strategies have already been implemented at some sites.
I assume that some of the places with the largest geothermal investments (ie. Iceland) don't suffer this problem that much.
It’s also better than drilling for oil/gas.. where you need to keep drilling constantly to get more oil/gas.
And as some here have pointed out, if there’s an excess of energy, which there will often be in a world with lots of renewables, you can pump heat back down into the reservoir, extending its lifetime.
So as always, at just comes down to cost. And I truly believe that if we put as much money into geothermal as we have with fossil fuels and nuclear power, it’ll be the cheapest and most environmentally friendly way of making power in a decade or two.
For horizontal or vertical geothermal loops, the biggest cost is always going to be digging for the loops. Until they make that more affordable, they're going to have a hard time making it more ubiquitous.
The real killer was knowing full well the house sits on or around a ton of limestone and the best quote I got told me it would cost a lot more if they hit rock.
The price a year ago would have been more like 20k, but with the crazy price of lumber and all building materials going up, the HVAC companies followed suit :(
If I did it a year ago it would be 20k less :/
An almost 100% increase is quite substantial, no?
https://www.constructiondive.com/news/skyrocketing-steel-lum...
https://www.benningtonbanner.com/local-news/cost-of-building...
And as I mentioned elsewhere, if I installed a horizontal loop, I'd have to cut down a ton of beautiful 100 year old trees surrounding the home. I'd rather not do that when there are viable alternatives. The cost of higher electricity usage isn't a big deal as I've got 48 bifacial solar panels on the barn that run to the home.
1. I'm not sure what "if you hit rock" means there.
In general, you want to hit rock, and should hopefully hit it very quickly (40-50ft), because rock generally has much better thermal conductivity than stuff like clay.
2. You hopefully got a loop design report that has real details on the load of your house and the design of the loop and how it meets them. The loop design should hopefully tell you they are mostly drilling in rock :)
Hopefully it all does not look like nonsense (I'm happy to look at it if you like, as are the folks over at forums like geoexchange)
3. The only units you should consider are waterfurnace, climatemaster, and maybe bosch.
Trane, for years, was using rebadged waterfurnace units At least browsing, it looks like they still are.
In any case, you want someone who does this for real, and Trane ain't it.
Bosch is an okay unit, but they are newer at this, and not obviously better in any meaningful way.
4. The price for single family residential drilling is high in part because it's not what the drillers want to be doing.
The rig setup takes them quite a while, the actual drilling is not that bad.
For multi-family residential (or commercial), where they are drilling 100 holes, it's much more cost effective.
So you are right in that sense - the current way of drilling is not going to bring the cost down.
On top of that, keep in mind you are probably paying significant markup on the drilling because it's being subcontracted.
Bosch as a general rule has pretty solid engineering. I've used their kitchen appliances for years and am quite happy with them. Unlike some of the korean vendors (I'm looking at you Samsung and LG, it is easy and fast to get parts when things break).
You're right that they're new at this, but all of the existing major appliances in the home are Bosch. If you buy more than three major Bosch appliances, they'll give you a fairly sizable discount.
When I said American Standard/Trane, I meant for the Central Heating and Air, not for the Geothermal. They're the same hardware and come off of the same assembly line with different stickers on them.
I've got a lot of experience in this, and what you are being given sounds like a bunch of nonsense, and yes sometimes you will get a bunch of nonsense from more than 1 HVAC firm. Lots do not specialize in geothermal, and see it as a way they can make additional profit off some people.
Concretely: At the price you are being given, the drill price should be fixed and included, excepting them hitting lots of water.
The driller certainly gave a fixed price, based on the local geography and what they are gonna hit. The know exactly what they will hit in terms of rock/etc.
The variable cost thing is not drilling rock or whatever, it's controlling water and sediment.
If they hit lots of water (IE 100+gallons a minute), controlling and remove it can be expensive and unexpected - most cities/etc have strict rules on this (so they can't just run it into the street). This is the thing that is hard to tell for them - it's rare to have good enough data to know exactly whether and where you will hit water, and it can even vary from hole to hole in the same job.
Otherwise, be careful - unlike regular HVAC, Geothermal requires people who really know what they are doing, and not just doing the kind of "finger in the wind" HVAC you can often find for folks doing heat pumps/furnaces. At a minimum, make sure you are using IGHSPA/etc certified folks.
If you want to get more into this, there are lots of knowledgable drillers and installers over in places like the geoexchange forums, and they won't steer you wrong.
As for Bosch, the units they are offering in residential are super basic units last i looked.
They are neither variable-speed pump or variable speed compressor.
They are simply 1-2 stage geothermal units. They appear to at least offer variable speed blowers on some of them, but that's very basic stuff.
This is the kind of unit you would have seen 20 years ago. I would not pay what you are paying for them.
Nice geothermal units (say, the waterfurnace 7-series) these days have variable speed pumps and compressors. They match themselves exactly to the load needed by the house over time, and run continuously at part-load, modulating up and down as they day goes on, and end up being both silent and very high efficiency.
They are also much longer life - parts like scroll compressors (and most forms of rotary compressors) are much happier if you modulate load rather than start/stop.
You don’t want to dig an 6ft trench through rock, but you should be able to drill through it if you’re drilling 70’ boreholes.
I have a couple bosch things, but their reputation as German Engineering is no longer true in my opinion.
I've followed much of the advice in this cleantechnica series on this exact problem: https://cleantechnica.com/2020/10/08/home-efficiency-101-app...
I had a geo system installed last December (GeoComfort with 3 200 foot wells for a 120 year old, 1600 sqft house).
The system works great except that the point where the aux heat kicks in for my house is 25 degrees F. I am working this year to improve the envelope to reduce the need for aux heat.
The article is opining about the deep "High Temp" thermal systems that are found in places like the Geysers field in California, in Iceland, and in New Zealand. Those use heat in a primary way to power heat engines to generate electricity.
You are talking about the other class of geothermal. That class is also known as "ground source heat pumps" for HVAC. Just like a reverse-cycle air-conditioner can heat as well as cool by exchanging heat with the outside air, ground source heat pumps do the same by exchanging heat with relatively shallow underground media. Typically, those have much higher heat capacities than air, which is the competition. Nobody attempts to run heat engines with such Low Temp resources as encountered in ground source heat pump applications...
Iceland seems to have some decent heat there: https://en.wikipedia.org/wiki/Geothermal_power_in_Iceland
Five major geothermal power plants exist in Iceland, which produce approximately 26.2% (2010) of the nation's electricity.
[1] https://en.wikipedia.org/wiki/Electricity_sector_in_Iceland#...
More widely deploying ground source heat pumps for home heating seems more promising than pursuing geothermal electricity generation. The problem with ground source heat pumps is that the lifecycle of the equivalent if 30-50 years, well outside the typical homeowner's planning or payback horizon.
I don't think this will ever be the case. Water-to-water (ground source) and air-to-water (air source) heat pumps are effectively the same thing technically sans some tuning for temperatures, therefore the difference in cost of the heat pump itself is never going to be high.
The cost difference is in installation costs. Air-to-water heat pump installation is as simple as mounting the external unit and routing a few pipes back to interior unit while water-to-water installation is routing the distributed heat exchanger, which is significantly more labor intensive even if you do not account for landscaping (e.g. done as part of greenfield development which will have landscaping done anyway).
The energy savings in the winter (US-MA) was nice -- heating from 60 is a lot less energy than heating from 30 or below -- but the summer was the real reason I'll absolutely install geothermal in any house I build: basically free a/c. Not having to think about setting the thermostat for a relatively large house down to 72 (or even lower, if you want to freeze your tookus off) is so freeing.
Some buildings that have access to the ocean or a lake can use that for heat rejection because those take the heat away.
None of these applications require going too deep in the ground. This article is all about going deep.
Iceland has access to very hot water in shallow ground. They are unique that way.
Modern air/air heat pumps are awesome.
On top of this 30k is on the high end for ground source heat pumps.
I bought this lovely house built in the 1910s...
> On top of this 30k is on the high end for ground source heat pumps.
Do note that this estimate included the cost for equipping the house with water-based radioators.
Nowhere has electric so cheap that a 2x or 3x reduction in the amount of electricity used to heat wouldn't result in massive savings.
Anyway, you only receive benifits when air temperatures are below the temperature of your ground loop. If the outside temperature needs to hit -4C before that happens you’re only benefiting from a smaller percentage of the year. Further that benefit is again constrained by the delta between resistance heating and what your ground source is providing the heat pump.
Generally it takes a combination of lower cooling costs in the summer and lower warming costs in the winter to make ground source heat pumps worth it, so being limited to a few months in the winter vs a 20+k installation cost is prohibitive.
When I priced it, this was normal. Perhaps $20,000 would be a a good price - https://www.youtube.com/watch?v=IMO9jvwlHFg&t=634s
Also I assume we are talking Geoexchange (For lack of a better word) not Geothermal. Temperature differentials not radioactive decay
Digging holes and installing infrastructure just costs too much money. Air heat pumps simple, things like being noisy is also getting solved which is awesome.
Right. It may be do-able, but unlikely to be cost effective in deep hard rock.
One of the deepest drilling projects got down 31,400 feet, but instead of hitting something saleable like natural gas or oil, they got liquid sulfur.
Solar water heating is extremely efficient (and less complicated), but I have never seen it in the US.
As for cooling, if it's hot out, the sun is probably out- solar PV with AC/heat pump should be fine.
I'm not sure either of our observations are useful to determine how prevalent rooftop solar water heating is.
It's generally not viable to just run a water pipe onto the roof, due to both freezing and temperature regulation concerns. So you end up with a closed loop system (filled with a glycol solution that won't freeze) and a heat exchanger to get the water into your domestic supply and at a consistent temperature.
Not to mention the service issues of having something "weird" on your house as a critical system.
Nowadays, we have electric heat pump water heaters that are very efficient, so running that in conjunction with solar panels to generate electricity can make a lot more sense in practice.
I had my AC replaced a few years back for like $3500, with "least efficient we can legally sell". Doing anything else was going to double the price, even though the wholesale cost difference to the next step up was under 20% of that.
I'd really just like to order my own equipment and pay an HVAC company's "day rate" to come out and install it, and I'll deal with surprises or warranty issues.
*https://www.oilgasequity.com/resources/drilling-completion-f...
https://www.energy.gov/energysaver/choosing-and-installing-g...
What?
Does anyone know why there’s a “.link” after “.eth”?
People prefer centralized services ~ who knew???
that's not why... it's because they don't know how to access the real source.
You can blame the chicken/egg problem, but ultimately the reason why decentralized systems don't overtake centralized systems is that they don't offer much of an advantage over them, so nobody cares enough to learn how to access them.
I mean, suppose Cloudflare/whatever goes down and the site is inaccessible: would you:
A) Grab the link, and go figure out how to pull it out of IPFS directly
B) Grab the link, and paste it into archive.org
or
C) Go grab a coffee, then come back and refresh the page (because when Cloudflare does go down, it tends to be only down shortly)
B and C aren't perfect, but they're close enough. Doing A takes effort and frankly isn't worth it unless you're doing it as a hobby.