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Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

lowtechmagazine.com

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Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#3

Post by notmadnomad »

For fixed-site applications of sufficient land area and scale, it's difficult to beat pumped-storage hydroelectricity (PSH). The round-trip efficiency is around or above 70%, the same or better than CAES. CAES is probably best used in applications similar to flywheel (FES), away from occupied areas.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#4

Post by Animats »

The system they like, the near-isothermal compressor with a "liquid piston", is described here.[1] They wrote up a description of a small prototype, but don't seem to have built one. The University of Arizona lab from which that paper came does not seem to be doing anything with energy storage any more.

[1] http://www.u.arizona.edu/~deymier/deymier_group/refs/CAES.pd...

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#5

Post by doitLP »

notmadnomad wrote: post #3

For fixed-site applications of sufficient land area and scale, it's difficult to beat pumped-storage hydroelectricity (PSH). The round-trip efficiency is around or above 70%, the same or better than CAES. CAES is probably best used in applications similar to flywheel (FES), away from occupied areas.

Do you have any recommendations on how to learn more about this?

My brother has a steep hill on his property and Ive been wondering about the feasibility of PSH. How high the tank should be, the equipment, the power output.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#6

Post by Animats »

wyldfire wrote: post #2

Another cool energy storage technique is using subterranean flywheels. They'd probably require less maintenance than other similar energy storage mechanisms.

Flywheel energy storage has been proposed many times, and built a few times. Flywheel-powered buses have been deployed. Not too successfully.

EMALS uses a big flywheel to power aircraft carrier catapults. The flywheel energy storage seems to cause most of the problems. The next generation of that system may use ultracapacitors.[1]

[1] https://www.ga.com/capacitors/military-mil-spec-capacitors

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#7

Post by [deleted] »

notmadnomad wrote: post #3

For fixed-site applications of sufficient land area and scale, it's difficult to beat pumped-storage hydroelectricity (PSH). The round-trip efficiency is around or above 70%, the same or better than CAES. CAES is probably best used in applications similar to flywheel (FES), away from occupied areas.

[deleted]

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#8

Post by PaulDavisThe1st »

notmadnomad wrote: post #3

For fixed-site applications of sufficient land area and scale, it's difficult to beat pumped-storage hydroelectricity (PSH). The round-trip efficiency is around or above 70%, the same or better than CAES. CAES is probably best used in applications similar to flywheel (FES), away from occupied areas.

TFA already says that large scale CAES is probably a dead end and that small scale CAES is where we might/should focus our attention.

Re: Ditch the Batteries: Off-Grid Compressed Air Energy Storage (2018)

#10

Post by telchar »

I'll admit this article describes a much less bad system than what I envision when someone mentions compressed air energy storage.

On a side note, I wonder what the state of research is on reducing the embodied energy in li-ion battery production. The mentioned figure in the article is surprisingly high (2-10 times the total energy the battery will store - presumably they mean over its lifetime), which now that I think aboute it, squares with what I have seen elsewhere on the embodied energy of electric car manufacture.

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