6 ms·

"Energy bills would be essentially zero," he says. I'm not sure how this statement is accurate (or relevant). Flywheels do not produce energy, they store kinet

by beambot 13y ago

"Energy bills would be essentially zero," he says. I'm not sure how this statement is accurate (or relevant). Flywheels do not produce energy, they store kinetic energy. Other comments... (1) I seem to recall an automobile developed in the 60s or 70s by another National Lab that siphoned off stored power from a flywheel (driven by a smaller motor). IIRC, they had hellish issues with handling since the flywheel created gyro effects as the car turned. [Sorry, I couldn't find a link to the project. ] (2) The failure modes for flywheels aren't pretty. This seems to be the big detractor from other technologies like the MIT microturbine [1]. You wouldn't want one of 'em to experience catastrophic failure when attached to the cellphone in your pants. To get sufficient shielding, you have to substantially up the weight of the power storage unit, thereby killing your power-to-weight ratios. [1] http://web.mit.edu/newsoffice/2006/microengines.html http://web.mit.edu/newsoffice/2006/microengines.html

dredmorbius 13y ago
The story leaves a lot to be desired in terms of defining technology and specifying methods. Depending on how you buy/sell power, and if you have access to TOU metering, you could spin up flywheels with cheap power and sell it back when rates are higher. If you've got your own generation on site (solar PV, wind, tidal), you could bank excess energy with flywheels. In terms of storage, flywheel round-trip efficiency is very, very good, above 90% for well-designed systems. The problem has always been storage density and cost. Beacon Power produces 25KWh flywheels priced at around $1000 /Wh. Add into this the failure modes (Beacon's systems are installed underground in concrete culvert pipe with a several-ton lid cap), and remaining problems with precession (even the Earth's rotation around its axis peturbs flywheels), and they have some significant hurdles. For mobile uses (automobiles, etc.) these problems are compounded. My money's on large, cheap batteries for grid-scale storage (molten salt or liquid metal), though flywheels for short-cycle load/generation matching may play a role.
- nitrogen 13y ago
  Beacon Power produces 25KWh flywheels priced at around $1000 /Wh. Is that really a $25mil flywheel? Or should that have been $1000/KWh? For mobile uses (automobiles, etc.) these problems are compounded. I'm probably demonstrating considerable mechanical naivety with this question, but could you balance multiple flywheels in different directions and orientations to mitigate these problems?
  - dredmorbius 13y ago
    Looks like I had my numbers a bit off. It's $10,000/KWh, putting each flywheel at about a quarter million. The cost data aren't clearly stated and I didn't find my earlier posts on this until just now: https://plus.google.com/104092656004159577193/posts/21sJzeSwQ11 https://plus.google.com/104092656004159577193/posts/21sJzeSw... Flywheels are used in cars, and the current generation of Formula One hybrids includes flywheel regenerative braking designs. While you can offset gyroscopic effects with counter-rotating flywheels, you still have the issues of loading the bearings of the individual flywheels due to vehicle vibration, movement, rotation, etc. Some of this can be mitigated by gimbal mounts, but that introduces increased volume requirements to the design, and avoiding gimbal lock requires four (rather than three) axes of rotation, one of which must be driven. It's one thing to have the flywheel last for the duration of a race, another for it to stand years of use in a private vehicle.
DanBC 13y ago
>Flywheels do not produce energy, they store kinetic energy. The article says, twice, that his design both stores and generates energy. Have they got something wrong? I'm aware that they're using the term 'flywheel' pretty broadly, and his newer device might not be a traditional flywheel. They use scare-quotes a couple of times when using the term flywheel, so they seem to be saying it's not a flywheel. > His latest project -- perfecting a prototype of his lightweight "flywheel," a cylindrical, rotating battery -- could revolutionize the energy industry, storing and creating energy better than any conventional electrobattery on the planet. > Post has been called the "father of the modern flywheel," a title he dismisses as "too generous." The rapidly spinning devices not only store energy with minimal losses, but they also generate it. The relevance is also mentioned in the story - he wanted to "apply physics to help solve the world's energy problems" and banks of these in power stations might help. Isn't storing the excess power generated by solar farms during the day a problem? Couldn't something like this help with that?
- ars 13y ago
  You can't just generate energy from nothing. A flywheel stores energy, it doesn't create it. So yes, they got something wrong.
  - whatshisface 13y ago
    "We said, 'To heck with electromagnetic, we're going with electrostatic,'" Post says, laughing. It's clearly not just a normal flywheel, perhaps it can convert some other energy form into electricity? (We call them "generators" don't we?)
    - mc-lovin 13y ago
      I'd guess that phrase refers to how energy is put into and taken out of the flywheel: using electrostatic force rather than electromagnetic.
      - EEGuy 13y ago
contingencies 13y ago
The Wikipedia article at https://en.wikipedia.org/wiki/Flywheel_energy_storage https://en.wikipedia.org/wiki/Flywheel_energy_storage claims that, in comparison to batteries, flywheels are not as adversely affected by temperature changes, can operate at a much wider temperature range, and are not subject to many of the common failures of chemical rechargeable batteries. They are also less potentially damaging to the environment, being largely made of inert or benign materials. A flywheel can potentially have an indefinite working lifespan. Flywheels built as part of James Watt steam engines have been continuously working for more than two hundred years. Another advantage of flywheels is that by a simple measurement of the rotation speed it is possible to know the exact amount of energy stored. Flywheels with Magnetic bearings and high vacuum can maintain 97% mechanical efficiency, and 85% round trip efficiency. Why aren't these in wide deployment yet as local storage for renewable energy sources? The biggest problems seems to be overall mass, cost, and space efficiency. None are great concerns for long term energy storage solutions for off-grid buildings. In short, these things sound fantastic. Anyone know where to buy one large enough to store power for a small draw, solar sourced home? This site explains a lot more about the concept, and engineering considerations behind two functional prototypes: http://home.earthlink.net/~fradella/homepage.htm http://home.earthlink.net/~fradella/homepage.htm Flywheels in vehicles were the subject on an article in the Economist in late 2011: Road tests have shown that, thanks to modern materials and clever design, a flywheel as small as a hockey puck can reduce fuel consumption by more than one-fifth. In electric hybrids only 35% of the kinetic energy lost during braking is retrievable. With flywheels more than 70% is. http://www.economist.com/node/21540386 http://www.economist.com/node/21540386 And someone just got funded on Kickstarter: http://www.kickstarter.com/projects/1340066560/velkess-energy-storage http://www.kickstarter.com/projects/1340066560/velkess-energ... .. they claim Energy storage flywheels have been in use for over 100 years and are some of the highest performing energy storage technologies ever developed. Traditionally, they have suffered one fatal flaw... they are extremely expensive! Velkess has invented a way of making energy storage flywheels at such low cost it will be dramatically less expensive than even the most economical energy storage technologies available today. Phys.org discussion of this effort: http://phys.org/news/2013-04-velkess-flywheel-flexible-energy-storage.html http://phys.org/news/2013-04-velkess-flywheel-flexible-energ...
- 13y ago
dredmorbius 13y ago
The Oil Drum has a pretty good reference on flywheel technology and reasonably recent developments as well: http://www.theoildrum.com/node/8428 http://www.theoildrum.com/node/8428
_pmf_ 13y ago
> I seem to recall an automobile developed in the 60s or 70s by another National Lab that siphoned off stored power from a flywheel (driven by a smaller motor). One possibly feasible application that comes to mind are automotive turbo chargers. Compared with current approaches, a flywheel does not actually seem that convoluted.

by beambot 13y ago

dredmorbius 13y ago

The story leaves a lot to be desired in terms of defining technology and specifying methods. Depending on how you buy/sell power, and if you have access to TOU metering, you could spin up flywheels with cheap power and sell it back when rates are higher. If you've got your own generation on site (solar PV, wind, tidal), you could bank excess energy with flywheels. In terms of storage, flywheel round-trip efficiency is very, very good, above 90% for well-designed systems. The problem has always been storage density and cost. Beacon Power produces 25KWh flywheels priced at around $1000 /Wh. Add into this the failure modes (Beacon's systems are installed underground in concrete culvert pipe with a several-ton lid cap), and remaining problems with precession (even the Earth's rotation around its axis peturbs flywheels), and they have some significant hurdles. For mobile uses (automobiles, etc.) these problems are compounded. My money's on large, cheap batteries for grid-scale storage (molten salt or liquid metal), though flywheels for short-cycle load/generation matching may play a role.

nitrogen 13y ago
Beacon Power produces 25KWh flywheels priced at around $1000 /Wh. Is that really a $25mil flywheel? Or should that have been $1000/KWh? For mobile uses (automobiles, etc.) these problems are compounded. I'm probably demonstrating considerable mechanical naivety with this question, but could you balance multiple flywheels in different directions and orientations to mitigate these problems?
- dredmorbius 13y ago
  Looks like I had my numbers a bit off. It's $10,000/KWh, putting each flywheel at about a quarter million. The cost data aren't clearly stated and I didn't find my earlier posts on this until just now: https://plus.google.com/104092656004159577193/posts/21sJzeSwQ11 https://plus.google.com/104092656004159577193/posts/21sJzeSw... Flywheels are used in cars, and the current generation of Formula One hybrids includes flywheel regenerative braking designs. While you can offset gyroscopic effects with counter-rotating flywheels, you still have the issues of loading the bearings of the individual flywheels due to vehicle vibration, movement, rotation, etc. Some of this can be mitigated by gimbal mounts, but that introduces increased volume requirements to the design, and avoiding gimbal lock requires four (rather than three) axes of rotation, one of which must be driven. It's one thing to have the flywheel last for the duration of a race, another for it to stand years of use in a private vehicle.

DanBC 13y ago

>Flywheels do not produce energy, they store kinetic energy. The article says, twice, that his design both stores and generates energy. Have they got something wrong? I'm aware that they're using the term 'flywheel' pretty broadly, and his newer device might not be a traditional flywheel. They use scare-quotes a couple of times when using the term flywheel, so they seem to be saying it's not a flywheel. > His latest project -- perfecting a prototype of his lightweight "flywheel," a cylindrical, rotating battery -- could revolutionize the energy industry, storing and creating energy better than any conventional electrobattery on the planet. > Post has been called the "father of the modern flywheel," a title he dismisses as "too generous." The rapidly spinning devices not only store energy with minimal losses, but they also generate it. The relevance is also mentioned in the story - he wanted to "apply physics to help solve the world's energy problems" and banks of these in power stations might help. Isn't storing the excess power generated by solar farms during the day a problem? Couldn't something like this help with that?

ars 13y ago
You can't just generate energy from nothing. A flywheel stores energy, it doesn't create it. So yes, they got something wrong.
- whatshisface 13y ago
  "We said, 'To heck with electromagnetic, we're going with electrostatic,'" Post says, laughing. It's clearly not just a normal flywheel, perhaps it can convert some other energy form into electricity? (We call them "generators" don't we?)
  - mc-lovin 13y ago
    I'd guess that phrase refers to how energy is put into and taken out of the flywheel: using electrostatic force rather than electromagnetic.
    - EEGuy 13y ago

contingencies 13y ago

The Wikipedia article at https://en.wikipedia.org/wiki/Flywheel_energy_storage https://en.wikipedia.org/wiki/Flywheel_energy_storage claims that, in comparison to batteries, flywheels are not as adversely affected by temperature changes, can operate at a much wider temperature range, and are not subject to many of the common failures of chemical rechargeable batteries. They are also less potentially damaging to the environment, being largely made of inert or benign materials. A flywheel can potentially have an indefinite working lifespan. Flywheels built as part of James Watt steam engines have been continuously working for more than two hundred years. Another advantage of flywheels is that by a simple measurement of the rotation speed it is possible to know the exact amount of energy stored. Flywheels with Magnetic bearings and high vacuum can maintain 97% mechanical efficiency, and 85% round trip efficiency. Why aren't these in wide deployment yet as local storage for renewable energy sources? The biggest problems seems to be overall mass, cost, and space efficiency. None are great concerns for long term energy storage solutions for off-grid buildings. In short, these things sound fantastic. Anyone know where to buy one large enough to store power for a small draw, solar sourced home? This site explains a lot more about the concept, and engineering considerations behind two functional prototypes: http://home.earthlink.net/~fradella/homepage.htm http://home.earthlink.net/~fradella/homepage.htm Flywheels in vehicles were the subject on an article in the Economist in late 2011: Road tests have shown that, thanks to modern materials and clever design, a flywheel as small as a hockey puck can reduce fuel consumption by more than one-fifth. In electric hybrids only 35% of the kinetic energy lost during braking is retrievable. With flywheels more than 70% is. http://www.economist.com/node/21540386 http://www.economist.com/node/21540386 And someone just got funded on Kickstarter: http://www.kickstarter.com/projects/1340066560/velkess-energy-storage http://www.kickstarter.com/projects/1340066560/velkess-energ... .. they claim Energy storage flywheels have been in use for over 100 years and are some of the highest performing energy storage technologies ever developed. Traditionally, they have suffered one fatal flaw... they are extremely expensive! Velkess has invented a way of making energy storage flywheels at such low cost it will be dramatically less expensive than even the most economical energy storage technologies available today. Phys.org discussion of this effort: http://phys.org/news/2013-04-velkess-flywheel-flexible-energy-storage.html http://phys.org/news/2013-04-velkess-flywheel-flexible-energ...

13y ago

dredmorbius 13y ago

The Oil Drum has a pretty good reference on flywheel technology and reasonably recent developments as well: http://www.theoildrum.com/node/8428 http://www.theoildrum.com/node/8428

_pmf_ 13y ago

> I seem to recall an automobile developed in the 60s or 70s by another National Lab that siphoned off stored power from a flywheel (driven by a smaller motor). One possibly feasible application that comes to mind are automotive turbo chargers. Compared with current approaches, a flywheel does not actually seem that convoluted.