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Re: Flywheel energy storage

Posted: Sun Aug 07, 2016 11:47 pm
by Skipjack

Re: Flywheel energy storage

Posted: Mon Aug 08, 2016 4:01 pm
by David_Jay
This is commercially available technology. Flywheel UPS systems with magnetic bearings (for zero wear) have been available for years. Here is just one supplier:

http://www.power-thru.com/flywheel_ups_technology.html

Re: Flywheel energy storage

Posted: Tue Aug 09, 2016 12:03 am
by Carl White
David_Jay wrote:This is commercially available technology. Flywheel UPS systems with magnetic bearings (for zero wear) have been available for years. Here is just one supplier:

http://www.power-thru.com/flywheel_ups_technology.html
Not for home use, yes. Probably only available at military prices. Also, the website hasn't been updated in three years, which makes me wonder whether business dried up after their initial order of 30 units.

Maybe Abigail Carson's innovation is to somehow make it all less expensive.

Re: Flywheel energy storage

Posted: Tue Aug 09, 2016 1:37 am
by Giorgio
Permanent levitation of Flywheels for energy storage has been around from several years in scientific literature.
I don't see anything in the Phys.org article that is "Revolutionary" in her design. It looks like a self promoting news release without any meaningful info.
Additionally they just made "theoretical" calculation, and as we all know very well, theory and reality tend to diverge as the applications becomes more and more extreme.

"Although with the initial aim of rotating at 100,000rpm, Miss Carson's figures show her design can easily rotate at 144,000rpm without any adjustment - this is massively more powerful and quicker than most existing designs, which can spin at around 60,000rpm"
The reason why most existing design spin at 60K RPM is due to material stress limitations.
Now, going from 60K RPM to 144K RPM will mean that for the same mass and the same diameter, the material of the rotating mass will have to withstand 6 times more the tensional stress!
Unless they show what type of material they are going to use with a proper tensional analysis at 100K RPM and 144K RPM, than this article is pure vaporware.

Re: Flywheel energy storage

Posted: Tue Aug 09, 2016 9:26 am
by KitemanSA
They are still high power, low energy storage devices.

Re: Flywheel energy storage

Posted: Tue Aug 09, 2016 12:07 pm
by ladajo
The reason why most existing design spin at 60K RPM is due to material stress limitations.
Now, going from 60K RPM to 144K RPM will mean that for the same mass and the same diameter, the material of the rotating mass will have to withstand 6 times more the tensional stress!
Yes! And, this has not changed since the last time we went down this path here.

Re: Flywheel energy storage

Posted: Wed Aug 10, 2016 12:07 am
by Carl White
Giorgio wrote:Unless they show what type of material they are going to use with a proper tensional analysis at 100K RPM and 144K RPM, than this article is pure vaporware.
Could it be some combination of graphite/carbon fibers and something else to provide the magnetism?

Meh, I guess PowerTHRU is already doing that.

Re: Flywheel energy storage

Posted: Wed Aug 10, 2016 7:11 pm
by KitemanSA
RPM is actually immaterial. It is tangential velocity that matters. The tangential velocity is limited by either the specific velocity or the characteristic velocity depending on the strong direction of the fly wheel. And the energy storage is proportional to the tangential velocity squared. The only things that will improve energy storage is greater specific velocity, or a system to provide radial force without drag.
Check out the Launch Loop for a way to get very high velocity without very high strength.