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Ditch the Batteries: Off-Grid Compressed Air Energy Storage

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

#111

Post by jandrese »

oori wrote: post #48
newman8r wrote: post #8

Earlier quoted context omitted.

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".

I think it is more typically done with old mines. Natural caves are far more complex systems and there are environmental concerns.

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

#112

Post by solarkraft »

skykooler wrote: post #40
brittohalloran wrote: post #11

Earlier quoted context omitted.

Similar to those gravity power modules: a company called Ares ( https://www.aresnorthamerica.com/ ) is trying to use much smaller concrete 'cars' on rails to store energy. Not sure of the status of it but it looked promising to me. The direct use of compressed air is interesting. Taking it to the extreme, you could have compressed air as your primary utility piped through your home, and have appliances that run off c…

I assume you'd still need electricity for things like lighting, right? (I can't think of a way to directly generate light from air pressure without converting it to electricity first.)

Generate heat through friction ... okay, that's crazy. But fire would work (& could be controlled through air flow).

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

#113

Post by throwaway5752 »

dwyerm wrote: post #89
throwaway5752 wrote: post #82

Earlier quoted context omitted.

There's a video somewhere of a failing flywheel, it's a fairly energetic explosion. I follow the energy space, also, and ... while I didn't expect Li batteries to have grid scale roles, I didn't think flywheels were going to succeed there. They have properties more like ultracapacitors (discharge rate suitable for continuous backup, clean up messy grid sine waves). I thought pumped air/pumped water was more likely be…

> it's a fairly energetic explosion So is a lithium battery explosion. So is a gasoline explosion. So is a flour mill explosion. So is a wind turbine explosion. Energy is energy, and losing control of energy is never great, no matter where it comes from. So while I catch your meaning, it might be better to phrase it with respect to how controllable that energy is. From what I know of flywheel storage, the problem mos…

I would disagree with you slightly. Energy is not totally fungible. I can punch you in the face or shoot you with a gamma ray (edit: though of course, I would never do either), and it would have very different effects, potentially. Same for a fastball vs a small caliber weapon. Heat, light, and kinetic energy are important distinctions - particularly when you have a bunch of 30k flywheels in close proximity and one of them catastrophically fails. Now, I know that's the first thing someone would think about deploying a bunch of them and they would take precautions. Li batteries are less kinetic and more thermal and that's a bit easier to manage/less likely to cascade.

I thought the trend in flywheels was magnetic suspension and removing mechanical linkages? Admittedly I haven't kept up.

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

#114

Post by ballenf »

dwyerm wrote: post #89
throwaway5752 wrote: post #82

Earlier quoted context omitted.

There's a video somewhere of a failing flywheel, it's a fairly energetic explosion. I follow the energy space, also, and ... while I didn't expect Li batteries to have grid scale roles, I didn't think flywheels were going to succeed there. They have properties more like ultracapacitors (discharge rate suitable for continuous backup, clean up messy grid sine waves). I thought pumped air/pumped water was more likely be…

> it's a fairly energetic explosion So is a lithium battery explosion. So is a gasoline explosion. So is a flour mill explosion. So is a wind turbine explosion. Energy is energy, and losing control of energy is never great, no matter where it comes from. So while I catch your meaning, it might be better to phrase it with respect to how controllable that energy is. From what I know of flywheel storage, the problem mos…

Also flywheels don't give off noxious fumes during failure.

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

#115

Post by jammi »

3pt14159 wrote: post #85
throwaway5752 wrote: post #82

Earlier quoted context omitted.

There's a video somewhere of a failing flywheel, it's a fairly energetic explosion. I follow the energy space, also, and ... while I didn't expect Li batteries to have grid scale roles, I didn't think flywheels were going to succeed there. They have properties more like ultracapacitors (discharge rate suitable for continuous backup, clean up messy grid sine waves). I thought pumped air/pumped water was more likely be…

The core insight for me was when Musk talked about how little the cost of Li mattered in the unit economics of Li batteries. It was something like 3% of the cost. The rest of it was mostly manufacturing costs. With so much room for improvements at scale and so many potential applications, it seemed like a sure winner.

Not only does materials overall matter little, but Lithium is also super cheap compared to the other materials in the batteries. There's a lot more of Nickel in a Li-Ion battery and it's much more expensive per volume and weight as well.

The batteries would be called Nickel-Carbon or something like that rather than Lithium-anything, if they were named by the amounts or costs of materials in them.

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

#116

Post by nrtd »

joncrane wrote: post #75
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…

Aren't flywheels used in datacenters to cover the split second between when the power goes out and the generators kick on?

I know about the RRZN where this is done.

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

#117

Post by jonknee »

JohnJamesRambo wrote: post #44

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.

Propane tanks seem like great bombs too, but they are really great for backyard grills. Solid engineering can make these things safe.

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

#118

Post by agumonkey »

jandrese wrote: post #98
agumonkey wrote: post #66

Earlier quoted context omitted.

few mechanical engineer~ youtubers said so many times; compressed gas seems less dangerous than water but compression is terribly dangerous

This doesn't make sense at all. High pressure water can be dangerous for sure, but water based energy storage doesn't use high pressure... It's all about pumping the water uphill and then letting the water flow back down through the pump to recover the energy. At worst your house gets flooded because the containment vessel failed. Worst case with compressed air is a total disintegration of the tank, the room it's in,…

my english is flawed, I was trying to say that. Water is not pressurized but feel scarier than air for most people, so they go care free around compressed gases.

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

#119

Post by leblancfg »

g8oz wrote: post #77

Also interesting is hydraulic energy storage. Any entrepreneurs want to take a shot with this system? http://license.umn.edu/technologies/z07054_hydraulic-energy-...

>Hydraulic energy storage systems store energy by compressing air similar to a battery storing energy in an electric circuit.

Wait, did you read the article? :)

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

#120

Post by matthewmcg »

pythonaut_16 wrote: post #107
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…

In a sense then you could say it's the Javascript of energy storage. Not the best on technical merits alone, but good enough along with a massive force of investment and wide adoption.

I think the surname of John B. Goodenough, one of the early Li-ion pioneers, is apt for the status of the technology.
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