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Ditch the Batteries: Off-Grid Compressed Air Energy Storage

lowtechmagazine.com

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Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#41

Post by sandworm101 »

mabbo wrote: post #31

> However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”. This would light a home for an hour, with LED bulbs and careful usage. And all it requires is a room-sized storage tank. So if I wanted somet…

Or you could liquify the air. That would make the storage much more energy-dense but introduces all sorts of practical/heat issues. People have played around with running cars on liquified nitrogen. The air conditioners probably worked well.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#42

Post by batbomb »

at-fates-hands wrote: post #29
drizzle87 wrote: post #24

I was quite excited by compressed air storage when Lightsail came into the picture almost 5-7 years ago. Sadly, they could not make the economics work and ended up pivoting into a company that sells carbon fibre tanks for high-pressure storage. As someone who follows the energy space closely, Lithium ion batteries now have so much momentum and $$$ pumped into them via R&D work, it's going to be hard for competing ene…

My concern with batteries is we're so gung ho on producing these, we haven't stopped to consider the environmental impact from the manufacturing process or the incredible task of recycling these once they've outlived their usefulness. It reminds me a lot of when people pushed plastic for everything in order to save the trees and reduce paper consumption. Some 40 years later, we're now trying to get off plastic and de…

Do you think it’s better or worse than the initial mining?

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#43

Post by adrianN »

harperlee wrote: post #38
tambourine_man wrote: post #30

Earlier quoted context omitted.

My knowledge of physics is very basic and practical engineering is zero, but storing hydrogen in compressed tanks always seem very impractical to me. It's the most freaking volatile element in the universe. And atomic hydrogen reacts with pretty much anything. Leakage and corrosion. From my armchair perspective, storying it in chemical bonds (like nature does) makes a lot more sense.

It would be great if there was a (safe, efficient) way to store electricity in ethanol - but it seems that the process is not very efficient and requires carbon monoxide as input, which is not very safe at offgrid-home scale. That is, unless electricity is used to light corn crops. Still not very efficient.

It's not really efficient, but you can create short chain hydrocarbons to store fuel for your fuel cell. Methanol for example is a lot easier to handle than hydrogen and there are fuel cells that consume it.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#44

Post by JohnJamesRambo »

I'm surprised no one is talking about how scary it is that you are basically making a high powered bomb at your house any time you have one of these. Anyone that has watched Mystbusters understands the incredible destructive power stored in compressed air. I'll stick with batteries, thanks.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#45

Post by VikingCoder »

mikeash wrote: post #28
VikingCoder wrote: post #14

Earlier quoted context omitted.

Nah, there's water-based computers, there could be compressed air computers. Picturing the different logic gates running on compressed air is a hoot.

You should check out Ted Chiang’s story “Exhalation.”

This seems to be a legal copy of it?

http://www.nightshadebooks.com/Downloads/Exhalation%20-%20Te...

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#46

Post by [deleted] »

hedora wrote: post #39
mabbo wrote: post #31

> However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”. This would light a home for an hour, with LED bulbs and careful usage. And all it requires is a room-sized storage tank. So if I wanted somet…

I thought this too, but read the rest of the article. Spoiler alert: State of the art is 30x better

[deleted]

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#47

Post by beat »

mabbo wrote: post #31

> However, to store 360 Wh of potential electrical energy, the system requires a storage reservoir of 18 m3, the size of a small room measuring 3x3x2 metres. The authors note that “although the tank size appears very large, it still makes sense for applications in rural areas”. This would light a home for an hour, with LED bulbs and careful usage. And all it requires is a room-sized storage tank. So if I wanted somet…

Depends on the tradeoff. The tl;dr of the article is that there's a tradeoff between pressure and efficiency. You can store at higher pressures in smaller vessels, but it's much less efficient. Low pressure (larger vessels) can be extremely efficient. In between, there are hacks to increase efficiency using heat exchangers and the like.

Beyond that, this is being pushed in the article as a rural/off-grid approach. For urban residential, it makes a lot more sense to centralize storage and run houses off a regular grid, than to try to make each house an independent entity.

In the medium run, we need to shift the grid itself from the current baseline+peak model to a solar+storage model (rolling wind into this), with distributed metering on the storage grid. Capture solar/wind power when the sun shines and the wind blows, and sell it when consumption outstrips supply, with pricing set dynamically on a distributed network.

Once you have that, for on-grid purposes, we'll probably see a diverse world of storage - car batteries, compressed air, industrial battery sites, water storage, thermal storage, etc.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#48

Post by oori »

newman8r wrote: post #8
jakecrouch wrote: post #7

Lightsail Energy tried and failed to bring this to market - not sure whether this can ultimately outperform Lithium Ion Batteries, which have all the pressure of the electronics industry behind them.

I feel like they have different applications so they're not necessarily competing. Obviously compressed air systems will never have the energy density of a battery, but they could be much more reliable. It also scales up really easily, and I think that's where the sweet spot is - I've heard of people sealing off caves to make giant air storage tanks for these projects.

"sealing off caves" - would love to see, or hear the facts. Specifically, about safety of the pressure "chamber".

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage

#49

Post by lr »

at-fates-hands wrote: post #29
drizzle87 wrote: post #24

I was quite excited by compressed air storage when Lightsail came into the picture almost 5-7 years ago. Sadly, they could not make the economics work and ended up pivoting into a company that sells carbon fibre tanks for high-pressure storage. As someone who follows the energy space closely, Lithium ion batteries now have so much momentum and $$$ pumped into them via R&D work, it's going to be hard for competing ene…

My concern with batteries is we're so gung ho on producing these, we haven't stopped to consider the environmental impact from the manufacturing process or the incredible task of recycling these once they've outlived their usefulness. It reminds me a lot of when people pushed plastic for everything in order to save the trees and reduce paper consumption. Some 40 years later, we're now trying to get off plastic and de…

This guy actually goes to a lithium "mine" in the middle of the desert...

https://www.youtube.com/watch?v=0KX2qw79qpk

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