Sep 28, 2023·edited Sep 28, 2023Liked by nephew jonathan
Interesting idea. I think the article spends way too much time talking about the hydrogen generation process though, which seems like it should just be simplified to "buy some hydrogen for this many dollars per kilogram".
Also, it is very US centric, which seems silly given that the article expressly suggests doing this over not-the-US. Surely you can find a tropical country where you can launch some big balloons from land, and probably right next to some plant that can produce grey hydrogen in large quantities. I would be much more interested in seeing the numbers run in such an environment rather than the whole "ferrying batteries out to a boat because the US regulatory apparatus is broken" thing.
I do think private actors will probably be using ships, but good point. I'll see if I can't write an addendum post in the next few days running the numbers on that.
I'm thinking that the biggest hurdle to overcome here will be the disappointment of the people who want global warming to require a generational character-building effort, rather than a mid-size government project budget and a few hundred people.
> $100/kWh isn't an unreasonable price to assume in the near future for lithium-iron-phosphate batteries (LFP)
> To keep battery lifespan high, we'll only run them them down from 80% to 20%
Unlike most lithium-ion chemistries, full charge and discharge doesn't stress LFP cells. They can handle thousands of deep cycles. For example, Tesla recommends you charge their LFP cars (like the standard-range Model 3) to 100% for daily use (compared to 80%, previously 90%, for the longer-range NCA chemistry).
If you use the full capacity of your LFP cells instead of keeping them between 20%-80% SoC, I believe you can revise your cost (for a given usable energy capacity) 40% downward, or revise your usable capacity (for a given cost) 67% upward.
"degrowth means the worst depression in the history of industrial civilization."
Sounds like you've read nothing about degrowth. Which is no surprise. No one else has, either!
Degrowth for the record (as actually advanced by degrowth scholars) does not necessarily involve reduced GDP. Interestingly enough. You have to expose yourself to the lit in order to understand this, and also to understand that degrowth scholars differ on some things and the "degrowth idea" cannot be fairly represented with simplistic abstractions. Cheers.
Really great stuff here! At COP28 right now and there's a notable absence of discussion of geoengineering. I think that even geoengineering at 5% of the scale described here would be really helpful in offsetting hard to decarbonize sectors, and I wish it was at least discussed and debated, rather than being taboo.
Hydrogen and butane balloons are both inflated. Balloon goes up. Chalk ejected. Butane cools down from the cold at that altitude. Condenses into insulated flask. Volume of craft shrinks. Craft now denser than air, so falls down again. Lands on ground. Refill the chalk. Boil the butane. Good to go again.
Or just a long strong tether that can pull the entire contraption back down.
Then you only need H2 to replace leaks. And need a lot of strong cable and a big winch.
What would the costs/feasibility look like to just use power from a ship’s diesel-electric engine to power the electrolyzer instead of ferrying batteries to and from shore?
How will the aerosol stay suspended in the stratosphere? Are there any chances it will drift into the troposphere and what are the implications of this?
- Curious about these questions even if they seem dumb
"This is what causes global warming in the first place—CO₂ is quite good at absorbing wavelengths the sun produces a lot of."
This is not correct. CO2 is quite transparent to sunlight but good at absorbing radiation the Earth emits -- that's what makes it a greenhouse gas. Also be careful not to be fooled by the us of the word "infrared", which can refer to a broad section of the spectrum. Even though both emit a lot of "infrared", there is very little overlap between the sun's spectrum and the Earth's. And CO2 absorbs longer wavelengths emitted by the Earth. See https://en.m.wikipedia.org/wiki/Outgoing_longwave_radiation
It might be worth comparing how your candidate aerosols are heated by long wave infrared. No idea if that would change anything.
Incidentally this is related to one of the limitations of SAI -- it doesn't exactly cancel out the greenhouse effect, because SAI only is effective during the day but GHGs trap great at night too. Increasing GHGs+SAI to balance still changes the climate, with cooler days and summers and tropics and warmer nights and winters and poles and also generally drier. Still on balance worth doing some of this at this point as we accidentally proved with the sulfur ban.
More minor nit-picks and questions:
"It's also why we think of infrared wavelengths as 'heat radiation'—they're not heat in and of themselves, but organic molecules like those found in humans or reptiles are very good at absorbing them."
Uncertain about the truth of this one. I believe the main reason is just that there is a lot of infrared radiation around compared to visible radiation, but visible radiation can also warm you up.
"TiO₂ is great at reflecting the visible light that represents the lion's share of what the sun gives off, but it's also very good at absorbing UV wavelengths. While this might sound like a good thing, what it means in practice is that stratospheric TiO₂ particles will cook the stratosphere."
Know what else heats the stratosphere? Ozone, for the same reason! I guess don't overdo it, but since ozone remains below historic levels you can afford to throw some sunscreen into the mix.
As for where to release, what the analysis misses is that the most powerful feedback effects, and thus the most dramatic temperature changes so far, are in the Arctic. Cooling Northern Canada a little means snow sticks around longer in the spring, which means sunlight is reflected away, which means your little bit of cooling turns into a lot of cooling. Seriously, don't forget to cool the Arctic!
"We then run a pump on board ship that draws 80% of the hydrogen out through the tether and feeds it into Balloon 2, a three-hour process; the remaining 20% (600 kilograms) is lost and has to be replenished anew."
Not sure I understand the point of this. Counterproposal: balloon 1 is attached to a (kevlar?) cable tether (not a tube) which is connected to a pulley and is also the tether for balloon 2. Raising one balloon lowers the other -- sort of like how funiculars always have two cars attached to one cable to act as counterweights to each other. No need to let hydrogen out. What is the downside to this approach?
> Increasing GHGs+SAI to balance still changes the climate, with cooler days and summers and tropics and warmer nights and winters and poles and also generally drier.
Well if we have desal so don't need rainfall.
Then great. Lets do lots and lots of this. That sounds like perfect weather.
If you can tether the balloon and winch it back down after releasing the payload, why do you still have to replace some of the hydrogen every time?
If you can't winch it back down (the abstract you linked mentions not wanting "to fly through the jet stream while tethered to the ground or sea"), pumping the hydrogen out through the tether sounds very impractical given how light the tether has to be. Remember the hydrogen pressure inside the tether would be far less than the atmospheric pressure outside due to the lighter weight of the gas column pressing down on it - so to avoid collapse, the tube would need to be thick walled.
Yeah, sucking it out through a tether will never work.
If you want to reuse the hydrogen, you need to fit the balloons with compressors. But then you need to power the compressors...
Probably easier to just vent the hydrogen and accept needing to produce more. Do all this from a friendly tropical country, rather than a ship, to avoid all that nonsense about ferrying battery packs.
Interesting idea. I think the article spends way too much time talking about the hydrogen generation process though, which seems like it should just be simplified to "buy some hydrogen for this many dollars per kilogram".
Also, it is very US centric, which seems silly given that the article expressly suggests doing this over not-the-US. Surely you can find a tropical country where you can launch some big balloons from land, and probably right next to some plant that can produce grey hydrogen in large quantities. I would be much more interested in seeing the numbers run in such an environment rather than the whole "ferrying batteries out to a boat because the US regulatory apparatus is broken" thing.
I do think private actors will probably be using ships, but good point. I'll see if I can't write an addendum post in the next few days running the numbers on that.
>the amount we'd need to cool the earth off won't raise rainwater pH
Acids lower pH, not raise it.
Fixed the miswording--thanks!
I'm thinking that the biggest hurdle to overcome here will be the disappointment of the people who want global warming to require a generational character-building effort, rather than a mid-size government project budget and a few hundred people.
> $100/kWh isn't an unreasonable price to assume in the near future for lithium-iron-phosphate batteries (LFP)
> To keep battery lifespan high, we'll only run them them down from 80% to 20%
Unlike most lithium-ion chemistries, full charge and discharge doesn't stress LFP cells. They can handle thousands of deep cycles. For example, Tesla recommends you charge their LFP cars (like the standard-range Model 3) to 100% for daily use (compared to 80%, previously 90%, for the longer-range NCA chemistry).
If you use the full capacity of your LFP cells instead of keeping them between 20%-80% SoC, I believe you can revise your cost (for a given usable energy capacity) 40% downward, or revise your usable capacity (for a given cost) 67% upward.
Is anyone working on putting this into practice already? Via non-profit or commercial route?
We are, check out www.makesunsets.com
"degrowth means the worst depression in the history of industrial civilization."
Sounds like you've read nothing about degrowth. Which is no surprise. No one else has, either!
Degrowth for the record (as actually advanced by degrowth scholars) does not necessarily involve reduced GDP. Interestingly enough. You have to expose yourself to the lit in order to understand this, and also to understand that degrowth scholars differ on some things and the "degrowth idea" cannot be fairly represented with simplistic abstractions. Cheers.
Really great stuff here! At COP28 right now and there's a notable absence of discussion of geoengineering. I think that even geoengineering at 5% of the scale described here would be really helpful in offsetting hard to decarbonize sectors, and I wish it was at least discussed and debated, rather than being taboo.
Maybe what you need is a double balloon.
A bag of hydrogen, and one of butane.
Hydrogen and butane balloons are both inflated. Balloon goes up. Chalk ejected. Butane cools down from the cold at that altitude. Condenses into insulated flask. Volume of craft shrinks. Craft now denser than air, so falls down again. Lands on ground. Refill the chalk. Boil the butane. Good to go again.
Or just a long strong tether that can pull the entire contraption back down.
Then you only need H2 to replace leaks. And need a lot of strong cable and a big winch.
What would the costs/feasibility look like to just use power from a ship’s diesel-electric engine to power the electrolyzer instead of ferrying batteries to and from shore?
How will the aerosol stay suspended in the stratosphere? Are there any chances it will drift into the troposphere and what are the implications of this?
- Curious about these questions even if they seem dumb
Cool analysis. Some things that jumped out to me:
"This is what causes global warming in the first place—CO₂ is quite good at absorbing wavelengths the sun produces a lot of."
This is not correct. CO2 is quite transparent to sunlight but good at absorbing radiation the Earth emits -- that's what makes it a greenhouse gas. Also be careful not to be fooled by the us of the word "infrared", which can refer to a broad section of the spectrum. Even though both emit a lot of "infrared", there is very little overlap between the sun's spectrum and the Earth's. And CO2 absorbs longer wavelengths emitted by the Earth. See https://en.m.wikipedia.org/wiki/Outgoing_longwave_radiation
It might be worth comparing how your candidate aerosols are heated by long wave infrared. No idea if that would change anything.
Incidentally this is related to one of the limitations of SAI -- it doesn't exactly cancel out the greenhouse effect, because SAI only is effective during the day but GHGs trap great at night too. Increasing GHGs+SAI to balance still changes the climate, with cooler days and summers and tropics and warmer nights and winters and poles and also generally drier. Still on balance worth doing some of this at this point as we accidentally proved with the sulfur ban.
More minor nit-picks and questions:
"It's also why we think of infrared wavelengths as 'heat radiation'—they're not heat in and of themselves, but organic molecules like those found in humans or reptiles are very good at absorbing them."
Uncertain about the truth of this one. I believe the main reason is just that there is a lot of infrared radiation around compared to visible radiation, but visible radiation can also warm you up.
"TiO₂ is great at reflecting the visible light that represents the lion's share of what the sun gives off, but it's also very good at absorbing UV wavelengths. While this might sound like a good thing, what it means in practice is that stratospheric TiO₂ particles will cook the stratosphere."
Know what else heats the stratosphere? Ozone, for the same reason! I guess don't overdo it, but since ozone remains below historic levels you can afford to throw some sunscreen into the mix.
As for where to release, what the analysis misses is that the most powerful feedback effects, and thus the most dramatic temperature changes so far, are in the Arctic. Cooling Northern Canada a little means snow sticks around longer in the spring, which means sunlight is reflected away, which means your little bit of cooling turns into a lot of cooling. Seriously, don't forget to cool the Arctic!
"We then run a pump on board ship that draws 80% of the hydrogen out through the tether and feeds it into Balloon 2, a three-hour process; the remaining 20% (600 kilograms) is lost and has to be replenished anew."
Not sure I understand the point of this. Counterproposal: balloon 1 is attached to a (kevlar?) cable tether (not a tube) which is connected to a pulley and is also the tether for balloon 2. Raising one balloon lowers the other -- sort of like how funiculars always have two cars attached to one cable to act as counterweights to each other. No need to let hydrogen out. What is the downside to this approach?
> Increasing GHGs+SAI to balance still changes the climate, with cooler days and summers and tropics and warmer nights and winters and poles and also generally drier.
Well if we have desal so don't need rainfall.
Then great. Lets do lots and lots of this. That sounds like perfect weather.
You'll need lots of canals to irrigate the deserts. You may need new rivers.
If you can tether the balloon and winch it back down after releasing the payload, why do you still have to replace some of the hydrogen every time?
If you can't winch it back down (the abstract you linked mentions not wanting "to fly through the jet stream while tethered to the ground or sea"), pumping the hydrogen out through the tether sounds very impractical given how light the tether has to be. Remember the hydrogen pressure inside the tether would be far less than the atmospheric pressure outside due to the lighter weight of the gas column pressing down on it - so to avoid collapse, the tube would need to be thick walled.
Yeah, sucking it out through a tether will never work.
If you want to reuse the hydrogen, you need to fit the balloons with compressors. But then you need to power the compressors...
Probably easier to just vent the hydrogen and accept needing to produce more. Do all this from a friendly tropical country, rather than a ship, to avoid all that nonsense about ferrying battery packs.
Power the compressors with a hydrogen fuel cell?