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The Mechanical Battery

Article #295 • Written by Christopher S. Putnam

In a world where everything from our automobiles to our underwear may soon run on electricity, more efficient portable power is a major concern. After a century of stagnation, chemical and ultracapacitor batteries have recently made some strides forward, and more are on the horizon. But the most promising way of storing energy for the future might come from a more unlikely source, and one that far predates any battery: the flywheel.

In principle, a flywheel is nothing more than a wheel on an axle which stores and regulates energy by spinning continuously. The device is one of humanity’s oldest and most familiar technologies: it was in the potter’s wheel six thousand years ago, as a stone tablet with enough mass to rotate smoothly between kicks of a foot pedal; it was an essential component in the great machines that brought on the industrial revolution; and today it’s under the hood of every automobile on the road, performing the same function it has for millennia—now regulating the strokes of pistons rather than the strokes of a potter's foot.

Ongoing research, however, suggests that humanity has yet to seize the true potential of the flywheel. When spun up to very high speeds, a flywheel becomes a reservoir for a massive amount of kinetic energy, which can be stored or drawn back out at will. It becomes, in effect, an electromechanical battery.

The capabilities of such a device are as extraordinary as its unique design. A traditional lead-acid cell-- the battery most often used in heavy-duty power applications-- stores energy at a density of 30-40 watt-hours per kilogram: enough to power a 100-watt bulb for about 20 minutes. A flywheel-based battery, on the other hand, can reach energy densities 3-4 times higher, at around 100-130 watt-hours per kilogram. Unlike the battery, the flywheel can also store and discharge all that energy rapidly without being damaged, meaning it can charge up to full capacity within minutes instead of hours and deliver up to one hundred times more power than a conventional battery.

What’s more, it’s unaffected by extreme temperatures, boasts an efficiency of 85-95%, and has a lifespan measured in decades rather than years.

While the average person has probably never heard of a flywheel battery, the concept is starting to be taken seriously by commercial and governmental interests. Large corporations see flywheel energy systems as ideal for power backup applications because of their long lifespan and low maintenance. Power companies often use them for load-leveling purposes: maintaining a steady flow of electricity between power generation peaks, or storing surplus energy during low-demand periods to prevent brownouts later on. Applications such as laboratory experiments that require huge amounts of electricity are sometimes powered by a flywheel, which can be gradually charged up over time rather than placing a massive drain on the power grid all at once. And NASA is funneling considerable resources into developing flywheel systems, which they believe could completely replace batteries in space applications. Apart from a marked superiority in energy density and lifespan, flywheels have the unique advantage of providing energy storage and attitude control for a spacecraft or satellite in one easy package. When two flywheels aboard a satellite spin in opposite directions at equal speeds, the satellite will maintain its attitude; when energy is transferred between the wheels to speed one and slow the other, the satellite will rotate.

But it’s closer to the ground that we find perhaps the most exciting potential application for a flywheel power system. With the modern world's increasing awareness of the economic and environmental drawbacks of oil-powered automobiles, the electric car has taken on an almost mythical status. Despite decades of development, a practical electric automobile seems as far away as ever, and the limitations of current batteries are largely to blame—they’re sorely lacking in power, storage capacity, charge speed, durability, and lifespan. Flywheel energy storage could well be the solution, and we don’t even have to delve into the theoretical to imagine how such a system would work. In an almost forgotten piece of transportation history, the flywheel-driven vehicle was briefly a reality.

The Gyrobus
The Gyrobus

The Gyrobus was an obscure public transportation vehicle that saw service in Switzerland, Zaire, and Belgium during the 1950s. Electric buses were already common at the time, but they were restricted to traveling along a grid of overhead electric lines. The idea behind the Gyrobus was to free a bus from this prison of wires. Instead of a conventional engine, the bus carried a three-ton rotating steel wheel attached to an unusual electric motor. When the bus was parked at a charging station, the motor would accelerate the flywheel up to around 3000 RPM; then, when it was time to take off, it became a generator, converting the flywheel’s kinetic energy back into electricity which drove the bus’s wheels. The charging process took between 30 seconds and 3 minutes, and once charged a Gyrobus could travel 3-6 miles at speeds of 30-40 mph.

A host of problems with the design ensured a short life for the Gyrobus experiment. The bus’s flywheel sat on a standard bearing which frequently broke under the strain, and which rapidly drained the wheel’s energy through friction. The resulting need to recharge the bus every few stops proved to be a significant hassle. Furthermore, the massive wheel made a Gyrobus far heavier than a regular bus, and far less efficient. The Gyrobus was simply more money and trouble than it was worth.

The flaws in the Gyrobus’s design were serious obstacles facing any flywheel-powered vehicle, but almost all of them have since been overcome. The justification for the bus’s massive steel wheel, and all the problems that came with it, was basic physics: the heavier a rotating object is, the more energy it holds. Increasing the object’s rotational speed, which raises its energy exponentially quadratically rather than linearly, is a far more efficient way to add energy. But spinning a steel wheel too much faster would tear it apart. The Gyrobus’ designers were therefore stuck with favoring size over speed, but this is not the case for modern engineers. The solution came in the 1970s, when materials both stronger and lighter than steel began to appear. Today, carbon fiber flywheels exist that can be spun fast enough to hold 20 times more energy than steel wheels of equal mass—and these materials continue to improve. The delicate and energy-draining bearings that hindered the Gyrobus have also been made obsolete. It’s now taken for granted that any flywheel energy system will use magnetic bearings, which levitate the wheel within a vacuum enclosure so that it spins in a nearly friction-free environment.

A magnetic bearing
A magnetic bearing

Flywheels in a system like this can glide along for months once they’re fully spun up, and under experimental conditions some have spun for up to two years without outside influence. If some friction is present, the wheel can be kept at full charge indefinitely by trickling in just enough energy to overcome it.

With these advancements, it seems that it may at last be time to see the return of the flywheel-powered vehicle. These new machines may bear little resemblance to the Gyrobuses of yesteryear, however. The design that received the most attention in the last decade was the brainchild of Dr. Jack Bitterly, chief engineer for the company US Flywheel Systems. Bitterly had dreamed since the 1970s of building an entirely flywheel-driven car, but it wasn't until the 1990s that the technology began to approach the necessary sophistication. Like the mechanism in the Gyrobus, Bitterly’s system featured a combination electric motor/generator to add and draw power from the flywheel; but this flywheel was made of computer-molded carbon fiber and spun silently on magnetic bearings at 100,000 RPM. Enclosed in a reinforced vacuum container, the whole contraption weighed less than one hundred pounds and could deliver a steady 20 horsepower, or 50 hp in shorter bursts. Bitterly’s idea was to put 16 of these units into a regular-sized car, which would generate 800 hp and travel 300 miles on a single charge—about the same range as a tank of gasoline, but at a cost of around 5-10 dollars. Despite some interest from major car companies, Bitterly and US Flywheel Systems were unable to secure enough support to get their design off the ground.

A number of obstacles held back development of a practical flywheel car, and they remain to this day. First, magnetic bearings are not yet up to the task demanded by a moving vehicle. Keeping a flywheel spinning in a laboratory or in the weightless vacuum of space is one thing; spinning it within the inertial jungle of a speeding car—contending with swerves, stops, and bumps—is an entirely different matter. The bearings must adjust on-the-fly to the sizable g-forces produced by ordinary driving in order to prevent energy loss and damage from flywheel “touchdown.” Even in perfect conditions, current magnetic bearings are not without flaws: they are expensive, unreliable, and drain excess energy through eddy currents, random electrical flows in the system.

Chrysler's Patriot prototype
Chrysler's Patriot prototype

Another problem unique to flywheel designs is the gyroscopic effect, which causes spinning objects to resist changes to their orientation. Obviously this is not a desirable trait when a vehicle is attempting to turn corners.

Finally, safety is a constant concern. A compact flywheel system such as Bitterly’s carries roughly the kinetic energy of a military tank traveling at highway speed, all of which must be released very quickly if the flywheel breaks apart or falls off its axle. Numerous deaths have resulted from just such failures throughout the history of modern flywheel design. This issue ultimately caused the scrapping of the Chrysler "Patriot," a hybrid racing vehicle built in the early 1990s. The car featured a 58,000 RPM flywheel as part of its drive system, but the power of the wheel could never be safely and practically contained. The difference between a potentially deadly failure and a harmless disintegration is the strength of a flywheel's container—but designers must balance strength with mass in order to keep a vehicle’s weight down. The perfect materials and design for such a container have not yet been found.

None of these problems are insurmountable. Magnetic bearings have plenty of potential for improvement and cost reduction: the biggest advance might come from passive magnets made out of superconducting materials, which would eliminate the problems with energy drain and most of the control hardware. The gyroscopic effect, meanwhile, can be largely canceled by mounting the flywheel enclosure on a gimbal or by pairing each flywheel with a counter-rotating partner. And the risk of flywheel failure can be managed; after all, engineers long ago managed to tame gasoline, a far more dangerous energy storage medium that has surrounded us for the last century.

NASA's 41,000 RPM G2 flywheel
NASA's 41,000 RPM G2 flywheel

As with most technologies, the time needed to develop these solutions is a matter of interest, ingenuity, and money. Frustrated by the lack of available funding for a full-fledged automobile project, most flywheel companies, including US Flywheel Systems, have shifted their focus to large-scale business and space projects. This change could be seen as a setback, but in the end it may simply be a more roundabout route to the same goal: once flywheels are proven in such demanding functions as powering the International Space Station, they will be taken seriously for more everyday tasks as well.

When examined closely, it’s striking how many of civilization’s energy and environmental problems can be traced back to inadequate energy storage. Humans happily rely on storage methods with efficiencies as low as 20%, wasting far more energy than we actually use. Automobiles continue to be a top contributor of pollution because they’re driven by a crude and dirty energy medium, and alternative “clean” energy sources such as wind and solar are restricted by the lack of an effective "potter's wheel" to keep the power flowing during down periods. When civilization first harnessed the power of the wheel, the achievement brought about a new era for humanity. Today the wheel seems poised to bring about another such change, and though the impact this time might not alter civilization as we know it, it may yet prove to be revolutionary.

Article written by Christopher S. Putnam, published on 12 October 2007. Chris is a writer and bomb-disposal expert for the Damn Interesting A-Team. He posts from an undisclosed location in Saskatchewan, Canada.

Edited by Alan Bellows.

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111 Comments
magkneetoe
Posted 12 October 2007 at 05:12 am

How about a flywheel battery for my phone...

Somehow I dont think that would work.


HiEv
Posted 12 October 2007 at 05:17 am

Still, you need to spin up the flywheel using some conventional method, which often means that you're adding another step to the process by using one. However, as mentioned in the article, the flywheel does have some advantages that can help make up for that. For example, I don't know if you remember BattleBots, but flywheel based weapons were often the most powerful and destructive ones once they got up to speed because they were able to store up so much power and then release it on impact with another robot.

It will be interesting to see how much flywheels are incorporated into future designs.


InterestedOne
Posted 12 October 2007 at 05:51 am

I'm not sure which is more interesting - the article, or that no one has said, "First", or "second".
Either way, I'm looking forward to seeing this in production.


11of10
Posted 12 October 2007 at 06:26 am

Impressive. I also first thought about a gyrobattery for my cellphone, but, i think it would perhaps receive even more g-force than the one in the car. Now, does anybody have any idea how to secure this flywheel from going berserk once it's off it's magnetic bearings?


kgy121
Posted 12 October 2007 at 06:41 am

InterestedOne said: "I'm not sure which is more interesting - the article, or that no one has said, "First", or "second".
Either way, I'm looking forward to seeing this in production."

Well, fifth then.


kgy121
Posted 12 October 2007 at 06:42 am

If I ever manage to make money, I'm definitely investing in one of these. It'd be like investing in Apple way back when.


Radiatidon
Posted 12 October 2007 at 06:54 am

Christopher S. Putnam said ”unique to flywheel designs is the gyroscopic effect, which causes spinning objects to resist changes to their orientation.

As stated a flywheel resists change in its angular location. In playing with various test apparatuses during the 1970,s & 1980’s, we strove to design and build a “floating” cradle to contain the flywheel. This cradle would in theory keep the flywheel facing in the same direction no matter how the vehicle moved and/or turned. Theory does not always pan out in the real world.

Christopher S. Putnam said ”all of which must be released very quickly if the flywheel breaks apart or falls off its axle.”

We did sufferer various breakdowns, as the flywheel’s mounts would shatter under the extreme forces that such a device operates under. Also we had a casualty when one test apparatus had a minor flaw in structure of that flywheel.

We had powered-up the flywheel and was preparing to test yet another combination of bearings, magnets, and high tensile frame structure. It was giving off a most pleasant thrum and there was hardly any deviation in the floating axis. Suddenly there was a weird sounding pop, and the warning systems came on-line. This shut down the power to the flywheel and engaged the slow-brake to power down the spin. Unfortunately this was too little and too late. The floating axis shifted and sent harmonic vibrations throughout the support structure. With an ear-piercing squeal the highly spinning metal gave off its death cry. The device literally came apart sending shrapnel in a vector perpendicular to the common axis of the flywheel. The safety shield that incased the device did not live up to its design as the debris tore through it like so much tissue paper. Unfortunately there was a fellow standing in front of it when this happened. Like a scene out of some sick horror flick, he was instantly split from crotch to forehead. Considering the amount of damage, it was amazing that we suffered only the one death.

The project was canceled shortly after that.

…as interesting as this article is, I wish that I had not read the damn thing. It brought back bad memories. Memories that are just as vivid as if it just happened. I was standing next to him, and as he fell I tried to catch him...


jbigdog
Posted 12 October 2007 at 07:02 am

Flywheel technology seems like it would be a great way to enhance solar. Imagine a home with a big, buried flywheel out back with a solar panel hooked up to it. Then you don't run into down time issues on a cloudy day, or at night. Wind works, too. Can anyone think of a reason that wouldn't work?


BarryW
Posted 12 October 2007 at 07:22 am

I remember reading about the idea of flywheel cars about ten years ago. The obstacles to putting the idea into production don't seem to have changed.

I do like jbigdog's idea. That would solve the danger issue.


Kao_Valin
Posted 12 October 2007 at 07:42 am

jbigdog said: "Flywheel technology seems like it would be a great way to enhance solar. Imagine a home with a big, buried flywheel out back with a solar panel hooked up to it. Then you don't run into down time issues on a cloudy day, or at night. Wind works, too. Can anyone think of a reason that wouldn't work?"

Well if you used more power than that power source fed to you than it wouldnt matter to try to store that up. Energy is only stored past the point of usage. Plus one would need to burry that pretty deep depending on the size and speed we are talking about. You wouldn't wanna have it fly out of there during an earthquake and tear thru your house like a frieght train at full speed.

Would it be safer to have thousands of microscopic wheels inside a AA or one big one? Would it be less efficient? Would it be safer to have this made into a drum rather than a disc so it is a flying blunt object rather than a razor blade cruising thru the wind? I'd imagine one blunt object to be better than multiple waffer thin discs when it comes to being slowed by wind resistance should it break loose. After all this is being stored in a vacum so wind resistance is only problematic on the outside, not on the inside when its working normally. If it breaks out it should be so oddball it loses lots of power to wind resistance.


jbigdog
Posted 12 October 2007 at 08:22 am

@ Kao_Valin

I understand what you mean about the power usage issue. What I'm getting at is anytime you aren't using as much power as the solar panels produce, that surplus energy is being stored up in the flywheel for future use. We do the same thing now, except we use tradition batteries to contain that energy. If a flywheel system has a 90% efficiency compared to a traditional battery with 20% efficiency the end result would be much more power on tap when you need it.

Safety-wise, dirt or sand is capable of dampening a tremendous amount of kinetic energy. Even a freight train doesn't get that far if it slams into the side of a hill. I don't think it would have to be very deep.

However, there probably is merit to the idea of thousands of tiny flywheels storing up energy. I would think be more loss when compared with one large one, simply because the more bearings you have, whether they be magnetic or mechanical, the less efficient the whole system will become due to increased friction or resistance. But I'll bet it would still trump a chemical battery.


Radiatidon
Posted 12 October 2007 at 08:45 am

jbigdog said: "Flywheel technology seems like it would be a great way to enhance solar. Imagine a home with a big, buried flywheel out back with a solar panel hooked up to it. Then you don't run into down time issues on a cloudy day, or at night. Wind works, too. Can anyone think of a reason that wouldn't work?"

To my mind, cost and maintenance issues are the only factors.

First you would want multiple flywheels (about the size of a standard auto wheel, give or take). This way you have a redundant system should any fail, so you don’t end up with zero power. Also smaller flywheels lose kinetic energy faster than a larger one, that way should they ever get loose, the smaller ones would cause less damage than say a massive car-sized one. Not to mention that it is easier to move and replace any parts on say a 150-pound metal wheel than a one-ton plus metal wheel. You have to keep in mind though, the more parts to a system, the higher the maintenance and the more components that can and will fail.

Next you would want the system stored in a somewhat climate controlled area. This ensures a longer life span for the various components (rust and dirt cause friction which decreases your system’s efficiency). A hardened concrete structure would be best with a positive pressure system (filtered air blown into the structure so any dust/dirt is blown out when someone enters). Sort-of like those old bomb shelters they built during the 1950’s thru 1960’s. That way if there was a mount failure, and the safety brake (a marriage between both a friction brake and a magnetic braking system) failed to slow/stop the flywheel it would just rebound (hopefully) within the enclosure (each flywheel in its own room to decrease chances of it damaging the other systems).

The system would need to be designed so that your power usage will never cause the flywheels to drop below a certain RPM. The initial cost in energy to start the wheels moving from a dead stop is over three times what is needed to keep them spinning.

Without sitting down and doing some serious math, I’m not sure of the size required for a solar array to power the system. I do know that a well can use a 12-volt pump that runs continuously filling a gravity reservoir (water tower). That way when you use water, the pressure is not created by the pump but by the weight of the water in the reservoir and gravity pulling it downward. This system uses a small array and is cheap to replace when the motor wears out, and not to mention that the power to run it is free.

Living on a ranch, we incorporate two systems for our water usage, the low voltage system for daily use by animals and people, and both a 120 and 240-volt system for irrigating pasture and vegetable/fruit gardens. Though I have slowly been converting the crops into a low volume watering system and might be able to convert that well into a multiple low-voltage pump system. The system(s) only need to be designed by the GPM one may use on a peak day. Free sunlight and wind power is cheaper than corporate generated electricity any day of the week, as long as you perform preventive maintenance religiously.

Not a bad thought though.


Nicki the Heinous
Posted 12 October 2007 at 09:47 am

Damn! another article already! I'm happy that I'm having a hard time keeping up. Nice article :)


Gerry Matlack
Posted 12 October 2007 at 12:31 pm

HiEv said: " For example, I don't know if you remember BattleBots, but flywheel based weapons were often the most powerful and destructive ones once they got up to speed because they were able to store up so much power and then release it on impact with another robot."

A flywheel-based weapon like this? http://www.military.com/soldiertech/0,14632,Soldiertech_DREAD,,00.html

For systems that are buried outside of buildings, a foot or so of sand surrounding the normal containment structure should do wonders for absorbing the kinetic engergy - you've seen the runaway truck ramps alongside highways with steep straightaways? Just running the tires through sand a couple feet deep is enough to bring a runaway freight truck to a stop within a few vehicle lengths. For the shrapnel to be travelling with full immersion through the sand should give even better energy absorbtion. One important element of Bitterly's system is the way they used a computer to design a custom pattern for winding the carbon fiber that makes up their flywheel. The result is that it has the highest possible fiber to epoxy ratio, and as the carbon fiber is much stronger than the epoxy, the wheel can safely withstand much greater rotational speeds than normal high-strength carbon fiber.


Glenn
Posted 12 October 2007 at 12:54 pm

An article (http://www.sciencenews.org/articles/20070519/bob8.asp) in Science News earlier this year reported on flywheel research.

>

I would like to see a DI article/more info on these.


Glenn
Posted 12 October 2007 at 01:03 pm

(My prior comment previewed OK, but did not post properly.) I would like to see a DI article/more info on flywheel systems used by large corporations and power companies.


Prachand Ushma
Posted 12 October 2007 at 01:28 pm

Everything comes down to cost effectiveness...doesnt it

to setup any type of home flywheel storage will probably take a lot of money...unless it is commercialised and mass produced by a company...like..batteries.
So...
untill DURAWHEEL comes out...we are pretty much stuck with cells


wasnr
Posted 12 October 2007 at 01:56 pm

HiEv said: "...For example, I don't know if you remember BattleBots, but flywheel based weapons were often the most powerful and destructive ones once they got up to speed because they were able to store up so much power and then release it on impact with another robot.

It will be interesting to see how much flywheels are incorporated into future designs."

i for one, welcome our flywheel driven robotic overlords.


Daneman
Posted 12 October 2007 at 04:28 pm

I can see it now, in 50 years we'll have a battery the size of a quarter,with 1000's of microscopic flywheel systems inside,that will also somehow be able to recharge though solar or kinetic energy somehow.
I mean look at what we've done with electronics,from vacum tubes to stuff that would make me shake my head in disbelief if I wasn't typing on it.
Flywheel driven robotic overlords ha ha ha ha ah ha ha ha. dang funny!
Oh and this is my 1st ever post!! Hope I didn't spell too many words wrong or make some other grammatical error as I know some can be savage on the poor guy who goofs!!!


blueyoshi321
Posted 12 October 2007 at 04:28 pm

Doesn't energy increase quadratically with speed, not exponentially?


elifint
Posted 12 October 2007 at 05:21 pm

blueyoshi321 said: "Doesn't energy increase quadratically with speed, not exponentially?"

It sure does. I was going to post a correction, but you beat me to it!

To get the energy density up to the point quoted in the article, most of the rotor has to be moving well above the speed of sound in air. Hence the need for a vacuum!

As with many proposals for new energy systems (including hydrogen), this is an energy storage medium, not an energy source. But it still helps, since you can gain an awful lot by having an efficient way to store energy and smooth out the temporal variations of demand and supply.


supercalafragalistic
Posted 12 October 2007 at 07:06 pm

I love this article because it focuses on the future of technology-- something my imagination hooks into quite heavily. Specifically I'd like to comment that the writing of the article provides a nice background before going into detailed descriptions of the bus and other Flywheel ideas. Then it opens up again in the last paragraph with thoughts that are at once engaging and also leave me wanting more. To speak to your article's first sentence, I would love to wear electric underwear. Maybe such an underwear could also wash itself? Here is one electric underwear product online that I saw: http://uk.gizmodo.com/2006/03/20/warmx_electric_underwear.html


rev.felix
Posted 12 October 2007 at 08:36 pm

Radiatidon, is there anything you don't know? You're my hero.


z
Posted 12 October 2007 at 09:27 pm

For a while this sounded total sci-fi to me... but I'll be damned, they had built something like this? Whoah.


WHACrusaders
Posted 12 October 2007 at 09:50 pm

This can not be used to store energy on something that needs to change direction like a car. The problem is the energy needed to overcome the rotational inertia if the car needs to go up and down a hill (assuming the wheel's axis is orientated from ground to sky). Think of a wheel in Physics class and how hard it is to change the axis of rotation. A car or rocket/spaceship is fine if the direction change is left or right, but a considerable amount of energy is needed to change the axis of rotation relative to the field of gravity (angle up or down). I don't see how to recover the energy lost in making this type of direction change. This can be useful to store energy in a fixed location. In the case of a car the kinetic energy can be stored using dynamic breaking (See DI "Why not a wind-up car")


WHACrusaders
Posted 12 October 2007 at 10:12 pm

On a side note, rotational inertia can be used to accelerate a mass. I was running a Physics experiment in class where we were rolling a ball down an incline plain and we all noticed that the ball would accelerate (yes speed up) once it was on a level surface. It finally dawned on us that we were using a tract to roll the ball that was contacting the ball on the side and not on the bottom. Think of it this way, If I roll the ball from the side (like a 4 inch diameter ball rolling between two parallel 2x4's 3 inches apart) for each rotation the ball is moving only half of its circumference, (lets say 10 RPM). Once it hits level ground the ball still wants to move at 10 RPM but the mass is moving at half speed. The ball will loose it's rotational inertia and its RPM's but the mass of the ball will speed up.


forestpines
Posted 13 October 2007 at 01:09 am

A British company called Parry People Movers has been building experimental lightweight flywheel-powered railcars since the 1990s. None of them have so far been very successful, though.


hangar
Posted 13 October 2007 at 05:38 am

jbigdog said: "@ Kao_Valin

.... If a flywheel system has a 90% efficiency compared to a traditional battery with 20% efficiency the end result would be much more power on tap when you need it. ....

20% is too pessimistic for normal batteries even with losses in any associated chargers and inverters. E.g., Wikipedia quotes 72 to 90% efficiency for lead-acid batteries. Chargers and inverters would have similar efficiencies or better (e.g., I think 95% is reasonable for an inverter running at its best load). Even if your whole chain is at the bottom end of those ranges (a rather unfortunate piece of design) you'd still get around 35% efficiency.


jbigdog
Posted 13 October 2007 at 09:27 am

Ah, I was basing that 20% figure on the article. I should have looked it up before posting it.

In response to the questions about maintenance and cost, surely there's ceramics out there that are cheap (and heavy, which is a bonus for this application). If the wheel is ceramic and permanent ceramic magnets are used for bearings, it would never rust and probably last a couple hundred years, at least. Far north locales could even use pykrete (http://www.damninteresting.com/?p=475#more-475). Tensile strength would be my only concern, though, whether cheap ceramics or pykrete are used.

DI article and DI discussion ;)


DaveS
Posted 13 October 2007 at 12:58 pm

hangar said: "20% is too pessimistic for normal batteries even with losses in any associated chargers and inverters. E.g., Wikipedia quotes 72 to 90% efficiency for lead-acid batteries. Chargers and inverters would have similar efficiencies or better (e.g., I think 95% is reasonable for an inverter running at its best load). Even if your whole chain is at the bottom end of those ranges (a rather unfortunate piece of design) you'd still get around 35% efficiency."

I think they may be quoting efficiency for a lead-acid when in less than optimum
discharge/recharge conditions, like you'd find in a motor vehicle. They have a lot
of heating and loss when discharged at high current, compared to NiCd or Li.

The bursty power requirements of motor vehicles seems to lend itself better to
inertial batteries such as this, but I'd like to see some way of tapping the power
better than converting the rotational kinetic energy to electric energy through
a lossy generator, then re-converting it back to kinetic energy in a lossy electric
motor to drive the car.

With a chemical battery, at least the direct output of the chemistry is electrical
power, not shaft rotation that you have to convert to electric.


xircso
Posted 13 October 2007 at 02:41 pm

Is Chris' undisclosed posting location in Dog River?


HiEv
Posted 13 October 2007 at 04:31 pm

Smaller flywheels dramatically lose effectiveness. Keep in mind that if you halve the size of something, you end up with 1/8th the volume. So, smaller flywheels have a fraction of the mass, meaning less energy can be stored, and are likely much more fragile, requiring slower speeds for safe and reliable use. Those two things combined mean that one large sturdy flywheel is almost always better than multiple smaller ones taking up the same volume, at least in terms of efficiency and maximum power storage.


hangar
Posted 13 October 2007 at 06:17 pm

DaveS said: "I think they may be quoting efficiency for a lead-acid when in less than optimum discharge/recharge conditions, like you'd find in a motor vehicle.

I was responding to jbigdog's comment #11 which was about using flywheels in solar power systems.


wh44
Posted 13 October 2007 at 06:48 pm

WHACrusaders said: "This can not be used to store energy on something that needs to change direction like a car. The problem is the energy needed to overcome the rotational inertia if the car needs to go up and down a hill (assuming the wheel's axis is orientated from ground to sky). "

This was addressed in the article: put the thing on a pair of gimbals. Then, even when the car is no longer upright, the flywheel is.


Poor
Posted 13 October 2007 at 08:24 pm

Revolutionary... HAR! I almost choked on my bagel. DI. Are there actually any "Disclosed" locations in Saskatchewan?


spittingllama
Posted 13 October 2007 at 08:31 pm

I remember reading once about a Russian scientist who solved the problem of flywheels "bursting" when they had reached their limits of energy storage. He "wound" steel flywheels out of banding.
Where a steel disc would burst, the "wound" wheel would come apart and fill up the housing and come to a stop.
Similarly, I understand that many carbon wheels are also wound from filament that will come apart and fill up the housing in much the same way. But, whereas the Russian flywheels could be "re-wound", the carbon wheels turn into "fluff." If the housing is also made of carbon filament, it also reacts to the fly-wheel running into it by turning into the same "fluff" and slowly bring the wheel to a stop.

For what it's worth: I have no idea where or when I read this. It might even be from the Discover article, which I read years ago now.


Migwel
Posted 13 October 2007 at 08:42 pm

IBM employees left some flywheel powered torches at my work.
It has a "hand pedal" that you squeeze to power a LED array for 10 seconds or so, also this system is connected to a battery.
Since the owners were long gone, I thought I'd take it with me camping.
Damn useful.


cinndave
Posted 14 October 2007 at 01:15 am

jbigdog said: "Flywheel technology seems like it would be a great way to enhance solar. Imagine a home with a big, buried flywheel out back with a solar panel hooked up to it. Then you don't run into down time issues on a cloudy day, or at night. Wind works, too. Can anyone think of a reason that wouldn't work?"

Completely unnecessary. If you have solar panels, windmills, waterwheels, etc. on your property that's generating more electricity then you're consuming, the surplus is fed back into the grid and your meter starts to run backwards. By law, if you feed more electricity into the grid than you draw, the electric company gives you a check instead of a bill. Little known fact, but it's true!


oneeyechuck
Posted 14 October 2007 at 05:35 am

I remembered reading some old (late 70's-early 80's) stories in Analog SF/SF with flywheel powered cars and one character who wouldn't get in one for fear of the thing coming off its axle.

@ Radiatidon --- I finally figured it out, I know who you are!!! You are W.W. Smith, aka Lazarus Long. I know I'm right!!! ( please lemme know if Dora and the twins are coming to pick you up within the next 40 or so years... please ???)


DaveS
Posted 14 October 2007 at 10:02 am

spittingllama said: "I remember reading once about a Russian scientist who solved the problem of flywheels "bursting" when they had reached their limits of energy storage. He "wound" steel flywheels out of banding.
Where a steel disc would burst, the "wound" wheel would come apart and fill up the housing and come to a stop."

Steel is not as strong as carbon fiber, so obviously the Russian scientist wasn't spinning his flywheel at the kind of speeds the guy in the article was. So when it let go, there wasn't so much energy to dissipate.

A flywheel spinning *really* fast has a LOT of angular momentum, and all that energy has to go somewhere when it disintegrates. If you can convert it all to heat, then something gets pretty darn hot very suddenly, like BOOM. If you don't convert it to heat, then a lot of angular momentum has to be absorbed by the housing or housing mounts. Imagine the disk disintegrating, and your car engine either suddenly spins off it's mounts and out the hood, or if the mount was really strong, flipping or spinning your car, depending on the orientation of the disk. It's THAT much energy we're talking about.

Think of what would happen if you converted a whole gas tank of petrol suddenly into either heat (BOOM), or momentum (top fuel dragster or more, but not controlled).

Shrapnel is another issue, and what the carbon fiber or banding is about avoiding.


Wintermute
Posted 14 October 2007 at 01:51 pm

cinndave said: "Completely unnecessary. If you have solar panels, windmills, waterwheels, etc. on your property that's generating more electricity then you're consuming, the surplus is fed back into the grid and your meter starts to run backwards. By law, if you feed more electricity into the grid than you draw, the electric company gives you a check instead of a bill. Little known fact, but it's true!"

You're missing the point. A clean, home-based power generation system coupled with an efficient store device (i.e. flywheel) results in a completely self-sufficient home that can not only produce all it's own power, but can store enough to power the home long enough to get through the times when energy cannot be collected (i.e. night, windless days, etc.). If you completely eliminate the storage device, you are essentially letting the power grid serve as your energy reserves. So while you may produce excess energy that gets sold back, come nighttime you will start paying for electricity again. You may break even, but with a storage medium for the low-energy production times, any excess energy that is produced will be stored for your use first, and once full any remaining can be sold back to the grid. So your system would look like this:

Energy surplus
Sun + wind -> Solar panels and wind turbine -> house -> flywheel -> grid = +$X
(where X = energy buy-back rate * surplus energy)

Break even
Sun + wind -> Solar panels and wind turbine -> house -> flywheel = $0

Energy deficit
flywheel -> home = $0

Severe deficit
grid -> home = -$Y
(where Y = standard energy rates)

Without the flywheel, you get this:
Energy surplus
Sun + wind -> Solar panels and wind turbine -> house -> grid = +$Z
(where Z = energy buy-back rate * surplus energy)

Break even
Sun + wind -> Solar panels and wind turbine -> house = $0

Energy deficit
grid -> home = -$W
(where W = normal energy rates)

As you can see, by eliminating the storage medium, you eliminate an entire state where you will essentially be paying nothing and running of the stored energy. Without this, you will always spend at least part of the time paying for electricity. With a flywheel (or something similar), you could theoretically never draw any power from the grid. Granted you will probably sell more energy back to teh grid by eliminating the power requirements needed to charge your storage device, but would that be enough to offset the energy consumed each night from the grid?

Of course if you live somewhere that has perpetual wind, you don't really need to worry about any of this.


Bewildered
Posted 14 October 2007 at 05:00 pm

Or if you live in a place where there is no grid... The stationary flywheel is the best possible use for the current technology, then you can charge your batteries for your electric car when you get home with power stroed from sun/wind etc. A combination of storage mechanisms is far better than trying to jam one mechanism where it won't fit... If you did want a flywheel system in your car, you could use it to steer by trying to change the direction of the flywheel. You could even get the car to jump, probably quite high depending on how much energy you have and how you turn the wheel...


Goodtwin
Posted 14 October 2007 at 06:25 pm

"and today it’s under the hood of every automobile on the road, performing the same function it has for millennia—now regulating the strokes of pistons rather than the strokes of a potter's foot."
No, actually flywheels are only used in some cars, those with manual transmissions. There's a thin flexplate in an automatic transmission or transaxle; Lobes on the crankshaft counterbalance the connecting rods and pistons, not the flywheel. Internal combustion moves the pistons up and down within the bore, regulated by spark timing. The flywheel is used to transfer engine torque to the friction disc, throwout bearing and finally the clutch, and once these are turning at the same speed as the engine the clutch is released and the motion is carried through the gear assembly in the transmission (in rear wheel drive) to the drive shaft, or in a transaxle to the CV axles.


Im-postle-able
Posted 14 October 2007 at 08:49 pm

Again, great article! Gets the ole noggin thinkin!!

The obsession with mounting flywheels in cars is a little wierd, i would have thought the dangers associated with crashes etc would be far to big to deal with. Regardless of how strong the containing box is or how good the bearings are, i'd hate to see the leftovers from 2 flywheel cars having a head on collision!! :-o

The obvious application (as pointed out by many people already) would be to have flywheel power storage for homes.. a specially made basement type room with the aforementioned car tyre sized fly wheels would be brilliant for using your solar power at night time.. not very futuristic.. but practical by the sounds of things.


cutterjohn
Posted 14 October 2007 at 10:36 pm

As you can see, by eliminating the storage medium, you eliminate an entire state where you will essentially be paying nothing and running of the stored energy. Without this, you will always spend at least part of the time paying for electricity. With a flywheel (or something similar), you could theoretically never draw any power from the grid. Granted you will probably sell more energy back to teh grid by eliminating the power requirements needed to charge your storage device, but would that be enough to offset the energy consumed each night from the grid?

Of course if you live somewhere that has perpetual wind, you don't really need to worry about any of this."

Tbh, the net effect of either scenario will be the same for you.. If you can store enough power to fill your electricity needs at night without relying on the grid, you would make enough money selling power to the power company to offset the cost of your electrical use at night as well.

Considering this, depending on your needs, it would be better to sell your power back to the power company rather than store it.

- You don't have to purchase/maintain the storage equipment.
- You sell *all* your excess power to the power company. If you stored it, there would be losses of efficiency, so you would need even more capacity.
- Even with storage, you would be dependent on the grid for special occasions anyway, unless you had vastly more storage than your home needed for those times. You would also end up selling power back to them during light periods(though this is hardly a con. ;) )

Tbh though, i'm not sure i see the point in private power generation. You'll never compete with the power companies as far as efficiency goes, nor be able to provide the proper level of maintenance unless you are a zealot about it. The economies of scale pretty much demand that they will have more efficient infrastructure and lower purchase/installation/maintenance/operating costs.

I suppose some people just like being self sufficient.


chuckygobyebye
Posted 15 October 2007 at 01:47 am

Flywheels obviously still have a way to go, but I can see an immediate application -- computer power supplies. Think about a rack-mount UPS that, once charged, causes minimal drain, doesn't wear out and can keep your equipment going for hours. It's not in an accellerating environment and you could dictate that, if someone is working in the data centre, all flywheels muct be spun down as a safety measure in case of catastropic failure (I'd recommend putting these devices on the bottom rack).


Samillionaire
Posted 15 October 2007 at 01:51 am

How bout a betavoltaic Battery? http://www.nextenergynews.com/news1/next-energy-news-betavoltaic-10.1.html

:) also this article is adequately interesting :)


elifint
Posted 15 October 2007 at 07:19 am

Samillionaire said: "How bout a betavoltaic Battery? http://www.nextenergynews.com/news1/next-energy-news-betavoltaic-10.1.html

:) also this article is adequately interesting :)"

That looks pretty cool. I have to wonder if it'll actually be able to pump out the amps, though. Most of the energy supplied by the betas will be lost as heat. It would be pretty exciting if it could be made to work, but I sincerely doubt that they'll "reach store shelves in about 2 to 3 years" when they're still in the basic research stage. At the very least, there are regulatory hurdles to overcome. Selling significant amounts of tritium on the store shelves involves a lot of paperwork in certain countries! But it's clearly possible: http://www.glowrings.com/ shows tritium-based glow sticks bright enough to be "perceived by the unaided dark adapted human eye at a distance of some 50 metres in total darkness." Pretty cool, but a long way from the kind of power you'd need to run a laptop. It could work in principle, but it's a question of whether the numbers work out when you try to make it practical.

I take exception to their advertising copy, though: "Although betavoltaic batteries sound Nuclear they’re not." Um, yes they are! The electrons they're using for power come straight from the nucleus. They're just saying this because they know people are scared of the word "nuclear."


Nicki the Heinous
Posted 15 October 2007 at 07:53 am

Poor said: "Revolutionary… HAR! I almost choked on my bagel. DI. Are there actually any "Disclosed" locations in Saskatchewan?"

Not really. I can see him from here. He's by the tree.


soupisgoodfood
Posted 15 October 2007 at 08:14 am

wh44 said: "This was addressed in the article: put the thing on a pair of gimbals. Then, even when the car is no longer upright, the flywheel is."

It's very easy to say that, but now you have the problem of a more complicated transmission system. Perhaps there is good solution to this, or perhaps it's just to difficult at the moment.


nevinera
Posted 15 October 2007 at 11:39 am

DaveS said: "Steel is not as strong as carbon fiber, so obviously the Russian scientist wasn't spinning his flywheel at the kind of speeds the guy in the article was. So when it let go, there wasn't so much energy to dissipate.

A flywheel spinning *really* fast has a LOT of angular momentum, and all that energy has to go somewhere when it disintegrates. If you can convert it all to heat, then something gets pretty darn hot very suddenly, like BOOM. If you don't convert it to heat, then a lot of angular momentum has to be absorbed by the housing or housing mounts. Imagine the disk disintegrating, and your car engine either suddenly spins off it's mounts and out the hood, or if the mount was really strong, flipping or spinning your car, depending on the orientation of the disk. It's THAT much energy we're talking about.

Think of what would happen if you converted a whole gas tank of petrol suddenly into either heat (BOOM), or momentum (top fuel dragster or more, but not controlled).

Shrapnel is another issue, and what the carbon fiber or banding is about avoiding."

be very careful here. angular momentum is NOT energy. two flywheels spinning in opposite directions have a net zero angular momentum, and twice the energy.
Interestingly, it also eliminates the gyroscopic effect you are all so worried about.

"has to be absorbed by the housing or housing mounts." is particularly a problem. It doesn't, you see. you would have other materials present specifically to absorb that energy. this material would also absorb much of the energy, becoming hot; the conversion of energy to temperature depends heavily on the material though.


nevinera
Posted 15 October 2007 at 11:43 am

WHACrusaders said: "This can not be used to store energy on something that needs to change direction like a car. The problem is the energy needed to overcome the rotational inertia if the car needs to go up and down a hill (assuming the wheel's axis is orientated from ground to sky). Think of a wheel in Physics class and how hard it is to change the axis of rotation. A car or rocket/spaceship is fine if the direction change is left or right, but a considerable amount of energy is needed to change the axis of rotation relative to the field of gravity (angle up or down). I don't see how to recover the energy lost in making this type of direction change. This can be useful to store energy in a fixed location. In the case of a car the kinetic energy can be stored using dynamic breaking (See DI "Why not a wind-up car")"

you're missing a fairly basic solution. if you put two opposing flywheels in a container, the net angular momentum is zero. turning it in whatever direction you like doesn't cause a problem (though it can cause energy to move between the two wheels during accelerations. work that out sometime, it's an interesting physics problem)


TVarmy
Posted 15 October 2007 at 12:19 pm

I've heard of these, and I know they have a lot of great applications. Reading this article made me wonder if this would be a good way to store extra pedaling energy when one goes bike riding. It could just spin parallel to the wheel as you accelerate, or it could capture breaking energy through some complicated gear system. And then I envision that as one approaches a hill, he could simply tap a lever and apply that stored energy to rush up around the normal top speed of the bike.

I'm no engineer, so I don't know if it would work. But it seems like it'd be a good alternative to electric bikes, which tend to be really heavy and have limited battery life/range. You could just pedal this up to speed when it winds down.


bryane
Posted 15 October 2007 at 01:43 pm

oneeyechuck said: "I remembered reading some old (late 70's-early 80's) stories in Analog SF/SF with flywheel powered cars and one character who wouldn't get in one for fear of the thing coming off its axle."

I remember the same stories, although I seem to recall that that cars were all one-wheeled, and the flywheel was horizontal (and restarted every day :-).

Even mentioned that anyone attempting to look inside the flywheel chamber was killed "as if by a bomb" because the flywheel flew apart.


whosywhat
Posted 15 October 2007 at 02:03 pm

What about using compressed air for the mechanical battery? Anyone know how it compares to a flywheel? I read about a concept Hybrid truck (I think it was by GM) many years ago that stored the energy from braking as compressed air instead of batteries. The article pretty much explained the benefit of compressed air over batteries as being the removal of the losses due to converting from mechanical energy to electrical energy and back again.

So, like DaveS asked, why add even more losses by converting from mechanical(braking) to electrical(generator) to mechanical(flywheel) to electrical(generator) to mechanical(driving the wheels)? There's probably a good reason. Anyone know what it is?


DaveS
Posted 15 October 2007 at 02:09 pm

nevinera said: "be very careful here. angular momentum is NOT energy. two flywheels spinning in opposite directions have a net zero angular momentum, and twice the energy.

I am very careful.

I said, "A flywheel spinning *really* fast has a LOT of angular momentum". Of course, in a two-flywheel system, each flywheel has a lot of angular momentum, which taken together cancel, BUT do you really expect them both to fail at the same moment? I don't think it's realistic to count on two wheel canceling each other's momentum on failure.

Now, if you have a whole array of little wheels, it's likely they won't fail all at once, and each one that fails represents much less momentum and/or energy dumped than the total of all of them. That's probably why they build them small and modular, and array them.

nevinera said: "Interestingly, it also eliminates the gyroscopic effect you are all so worried about."

Not quite. It eliminates gyroscopic precession, yes. But a pair of gyros will still resist movement. You STILL have to mount it on 3-d gimbals to turn, bank, and go up hills, and as long as you're doing that, there's no reason to lock two together, just let them gimbal individually.

And if you're doing that, why bother to run them in opposite directions? Simpler to manufacture them all the same.

Now in SPACE applications, it's advantageous to have a fixed platform, and two gyros together makes for much simpler motion equations.

nevinera said: "has to be absorbed by the housing or housing mounts." is particularly a problem. It doesn't, you see. you would have other materials present specifically to absorb that energy. this material would also absorb much of the energy, becoming hot; the conversion of energy to temperature depends heavily on the material though."

Sure, a big heat sink would absorb a lot of thermal energy, but again we're talking about the energy in an entire car gas tank of gasoline (since it can push the car the same distance, plus vent lots of waste heat into the radiator and air, grok?). That's a lotta BOOM to absorb in something the size and weight of a car.


DaveS
Posted 15 October 2007 at 02:23 pm

nevinera said: "you're missing a fairly basic solution. if you put two opposing flywheels in a container, the net angular momentum is zero. turning it in whatever direction you like doesn't cause a problem (though it can cause energy to move between the two wheels during accelerations. work that out sometime, it's an interesting physics problem)"

I detect a lack of high-school physics classes where you might have played with gyroscopes.

There's a peculiar action-reaction behavior that gyroscopes have. If you apply a force to change the plane of the rotation, the force reaction of the force is applied at a right angle, and the gyroscope moves out of the plane 90-deg from your force, but not in the direction of your force. So it feels like the gyro is resisting your force, as it's not moving the way you're pushing.

If you link two opposing rotation gyroscopes together, and apply a force out of plane, they torque against one another, and no 90-degree motion takes place, but no motion takes place in the direction you're applying the force, either. In other words, it simply resists rotation out of plane. Push on it, and it resists, in any direction except in the common plane of rotation.

So it absolutely does not solve the need for gimbals to have two opposing gyroscopes linked together, if you want to maneuver in more than one plane.


Bluebrake
Posted 15 October 2007 at 06:07 pm

What if you had a horizontal flywheel (vertical axis, "z") set in just one gimbal so that it could turn freely in the front-to-back direction (call it axis "y")? Handling then wouldn't be an issue, and neither would going up and down hills, but it would be almost impossible to roll the car because the flywheel is stable along the "x" axis. So in other words, use the gyroscopic effect to your advantage?


craash420
Posted 15 October 2007 at 06:59 pm

Samillionaire said: "How bout a betavoltaic Battery? http://www.nextenergynews.com/news1/next-energy-news-betavoltaic-10.1.html

:) also this article is adequately interesting :)"

I created an account just to reply, because you must be joking. Look around that site a little more, check out their purported perpetual motion machine. Why bother with "betavolactic" batteries when you can have virtually unlimited energy for free?


Im-postle-able
Posted 15 October 2007 at 08:49 pm

Yeah that Betavoltic Battery is a hoax.. someone did the calcs on a blog and it turned out it would work.. but it would generate a stupendous amount of heat in the process.. so yeah..


wh44
Posted 16 October 2007 at 02:41 am

Bluebrake said: "What if you had a horizontal flywheel (vertical axis, "z") set in just one gimbal so that it could turn freely in the front-to-back direction (call it axis "y")? Handling then wouldn't be an issue, and neither would going up and down hills, but it would be almost impossible to roll the car because the flywheel is stable along the "x" axis. So in other words, use the gyroscopic effect to your advantage?"

Ever hear of "banked curves"?


whosywhat
Posted 16 October 2007 at 08:05 am

RE: Compressed Air battery
This site claims compressed air has an energy density of 34 Wh/kg which is not so good. http://wiki.xtronics.com/index.php/Energy_density


tankfox
Posted 16 October 2007 at 10:50 am

I'm surprised that nobody has mentioned trains yet! Commuter trains sound like a perfect application for this technology.

Right now most electrical commuter trains run with miles and miles of overhead wire. When one of those wires goes down, oop! You're stuck, baby! You get to pay to maintain not only the big metal track but also that thin, high voltage wire swinging around in the breeze. Why not instead install a flywheel array in each train?

Speed up with the flywheel array, recapture the energy when you brake, and top off at each station along the way. A train would not experience the same stop and go chaotic activity that plagues the idea of flywheel automobiles; with a train you know where you're staring and stopping and doing it however fast you please. There are no unexpected or sharp turns, no potholes, no banking. Even when you inevitably plow into a car the inertia of the train prevents a sudden high-g stress on the flywheel bearings.

The reduction in infrastructure required could more than make up for the added cost of the flywheel array. Tracks would no longer need the overhead wires anywhere except the stations and perhaps booster runs along extended stretches. No more problems with tall vehicles blocked from crossing commuter train tracks! No more dead lines stopping the show! With enough capacity in the array, trains could skip a dead station and refuel at the next!

I live in Minneapolis and I very much enjoy our new commuter rail line. If this new technology could make trains a more widespread and economical solution my hopes would be to see light rail a significant part of every city's infrastructure!


Radiatidon
Posted 16 October 2007 at 12:12 pm

forestpines said: "A British company called Parry People Movers has been building experimental lightweight flywheel-powered railcars since the 1990s. None of them have so far been very successful, though."

One type of people Mover that uses flywheels is the Segway. Follow the link for more on the science of it. If you ever get a chance, try one of these things out. You have to overcome the feeling that you are about to perform a face smack right into the ground, but these things are a joy to ride!

chuckygobyebye said: "Flywheels obviously still have a way to go, but I can see an immediate application — computer power supplies."

I don’t know about any power-system backups, but I do know that there are some hand-held computer mice that utilize flywheels. Giving the speaker freedom to move around the room, the accelerometer and a gyrometer in the mouse give signals as how fast the person’s hand is moving and in what direction. This in turn sends signals to the computer to move the pointer on the overhead screen. These things are a breeze to use, and no, the flywheels are small enough that you don’t feel the resistance to angular motion.

This same technology is in use by the gameheads. Anyone who has played a game on the new consoles, the Wii or the Playstation 3, are using controllers that utilize accelerometers and gyrometers.

Goodtwin said: "No, actually flywheels are only used in some cars, those with manual transmissions.

Not to differ here, but the large, bowl-shaped, revolving weighted wheelie thingie with a gear edge that is turned by the starter to start any auto engine (manual or automatic transmission) is actually a flywheel. The flywheel does two things;

(1) first it helps the starter to overcome the engines mechanical resistance to start.
(2) Due to the pistons up/down motion, or commonly called reciprocating motion, this can cause a lot of vibration in the crankshaft. The flywheel creates an opposing inertia of its own that counteracts with the reciprocating pulse from the pistons. This allows a more even transition of energy from the engine to the transmission. It also reduces engine vibration increasing the life of various components.

If you use a pull-start lawn mower (or any pull-start motor) then you have 1st hand experience of how beneficial a flywheel is. The pulley that the rope is wound around is attached to a weighted flywheel. When you pull the rope, it moves the pulley, and engages the flywheel. At the end of the rope pull, the pulley disengages from the flywheel, which continues to momentarily turn allowing the piston(s) to compress the fuel vapors and hopefully start the combustion process. The energy applied to the flywheel allows it to turn the motor mechanisms for operation faster and easier than you could by hand.

Or anyone who has ridden a bicycle or motorbike has also experienced the wondrous advantages of flywheels. The wheels of the bike act as a flywheel by keeping the vehicle upright. When the bike has enough speed, it moves in a fairly straight line even without a rider. As the speed decreases the bike will start to wobble until it finally falls over. The forces keeping the bike upright are created by the wheels acting as flywheels.

oneeyechuck said: "Radiatidon — I finally figured it out, I know who you are!!! You are W.W. Smith, aka Lazarus Long. I know I'm right!!! ( please lemme know if Dora and the twins are coming to pick you up within the next 40 or so years… please ???)"

Sorry, but Robert H. has left the planet. He was a good writer though.

cutterjohn said: "I suppose some people just like being self sufficient."

Hmm, a few years ago there was a very wet, very dirty storm. The power grid failed and six western states lost power, some places were without power for over a week. My ranch was not in the dark though. Thanks to a secondary system, we had light, water, and heat in a landscape of darkness. I was even able to supply my neighbor with power for three days by back feeding his place through an old, unused power-line.

Just some random thoughts,

The Don


ch
Posted 16 October 2007 at 12:54 pm

elifint said: "It sure does. I was going to post a correction, but you beat me to it!

To get the energy density up to the point quoted in the article, most of the rotor has to be moving well above the speed of sound in air. Hence the need for a vacuum!

As with many proposals for new energy systems (including hydrogen), this is an energy storage medium, not an energy source. But it still helps, since you can gain an awful lot by having an efficient way to store energy and smooth out the temporal variations of demand and supply."

this article sucks it is gay


ch
Posted 16 October 2007 at 12:54 pm

gay


Silverhill
Posted 16 October 2007 at 03:04 pm

(Please don't feed the trolls...nothing to see here...move along.)


digitalfox
Posted 17 October 2007 at 02:48 am

forestpines said: "A British company called Parry People Movers has been building experimental lightweight flywheel-powered railcars since the 1990s. None of them have so far been very successful, though."

So unsuccessful that the company has been chosen to provide motive power for a 7-day a week service on the Stourbridge, UK branch line by newly-appointed rail franchise holder London Midland! Visit http://www.parrypeoplemovers.com for the facts.


wargammer
Posted 17 October 2007 at 08:15 am

remember oil is NOT a fossil fuel
it, along with black coal and methane are products of the earth that do regenerate, slowly.

with room temp superconductors, the flywheel is a great idea


forestpines
Posted 17 October 2007 at 01:14 pm

digitalfox said: "So unsuccessful that the company has been chosen to provide motive power for a 7-day a week service on the Stourbridge, UK branch line by newly-appointed rail franchise holder London Midland! Visit http://www.parrypeoplemovers.com for the facts."

The Stourbridge branch is only 3/4 a mile long - a journey from end to end on it takes about three minutes, and it's completely isolated from the rest of the railway network. Success there hardly means the unit would be useful anywhere else, and people have complained in the past that Parry's units are slow, noisy, and require frequent recharging. The one trialled on the Welsh Highland Railway did not operate for very long at all before mechanical failure took it out of service. See some of the comments at http://groups.google.co.uk/group/uk.railway/browse_thread/thread/d6db157a3ddfd462/65cf1d427c3dace3 for example, or http://whr.bangor.ac.uk/ppm.htm


Bewildered
Posted 17 October 2007 at 06:19 pm

Don: Actually the Wii uses a thing more similar to a strain gauge, it's a MEMS micro-electro-mechanical-system similar to what is in car airbag sensors and military aircraft. A microscopic plate that changes resistance as it bends with the motion. Very interesting to see these minature things within consumer reach :-)


HunterKiller_
Posted 18 October 2007 at 03:36 am

I'm totally down with this idea. Great read.


Radiatidon
Posted 18 October 2007 at 07:07 am

Bewildered said “Actually the Wii uses a thing more similar to a strain gauge, it's a MEMS micro-electro-mechanical-system similar to what is in car airbag sensors and military aircraft. A microscopic plate that changes resistance as it bends with the motion. Very interesting to see these minature things within consumer reach :-)“

Oops, you got me there Bewildered. You are right that there is no gyrometer but the device does use an accelerometer.

I did some checking and was told that the Wii remotes (originally conceived for the Game Cube) had initially been designed with both the accelerometer and a gyrometer. After various tests the gyrometer was dropped as the accelerometer relayed the required information for function perfectly alone and was cheaper. This helped decrease the cost of the controller.

An accelerometer is a self-contained chip that uses a one millionth of a gram silicon weight connected by microscopic springs. Above the weight is a series of plates looking like a comb. As the weight moves beneath these plates it applies voltage to the ones in contact. In the neutral position the weight rests in the middle of the plates. This simple setup can indicate motion by the direction the plate moves (one plate for the x-axis, one for the y-axis, and one for the z-axis allowing the remote to “sense” 3-d motion) and speed by how fast it slides from one side of the comb-like plates to the other. It is a simple matter to compute the speed by how fast the voltages change from one plate to the next as the silicon weight moves a total of five nanometers. To get an idea of this distance, look at one of your hairs. On average the human hair is approximately 200 nanometers wide.

The size and tension of the springs depends on the use of the accelerometer. They are the basic components used to trigger airbags, part of the anti-shake in motion & picture cameras, protect harddrives if the computer is dropped, etc.

Depending on what flavor (abilities) of chip you want, they can be purchased at some electronics stores starting at around $2.65 and up.

Thanks for the catch Bewildered.

The Don


Silverhill
Posted 18 October 2007 at 02:23 pm

Radiatidon said: "...the silicon weight moves a total of five nanometers. To get an idea of this distance, look at one of your hairs. On average the human hair is approximately 200 nanometers wide."
Greetings, "Don Radiati"! Excellent, informative response, as usual. However, there's one teensy factor-of-500 error there. Human hair averages 99 micrometers in thickness (range: 17 - 181 micrometers), or 99 000 nanometers. (This makes the distance-of-travel of that weight even more impressive in its tininess!)
Cheers,Silverhill


camerondmm
Posted 18 October 2007 at 08:58 pm

Just wanted to point out something.
I enjoyed your comments Radiation, but you I believe you are wrong about the gyroscopic affects of bicycle wheels. Please refer to the 1st paragraph of http://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics for more information. The article references 2 papers in making this counter-intuitive statement. I discovered this just this past summer while working on some bicycle designs. It really bemuddled me at 1st and through a monkey wrench into my plans.
Regards!


HiEv
Posted 19 October 2007 at 05:22 am

wargammer said: "remember oil is NOT a fossil fuel
it, along with black coal and methane are products of the earth that do regenerate, slowly."

Didn't we cover this elsewhere? Assuming you're talking about oil that comes out of the ground (a.k.a. petroleum), no, the vast majority of crude oil appears to come from what was originally an organic source (see here), thus is a fossil fuel. Methane, a potent greenhouse gas, is also a product of organic breakdown (see here), which makes the underground sources of it a fossil fuel too. Anyways, the things you discuss are all pollutants and there is no way that they're being replenished fast enough to supply the world economy, let alone one good sized city. Alternative fuel sources are needed.

wargammer said: "with room temp superconductors, the flywheel is a great idea"

Unfortunately, room-temperature superconductors do not exist yet, so it's hard to say how expensive, fragile, and toxic it might be if one is ever found.


Radiatidon
Posted 19 October 2007 at 06:26 am

camerondmm said: "Just wanted to point out something.
I enjoyed your comments Radiation, but you I believe you are wrong about the gyroscopic affects of bicycle wheels."

Actually my statement is partially true. The wheels do produce a gyroscopic effect, though they are not the only devices that help keep a bike upright as you pointed out, and my statement was way too general (is it getting warm in here?).

My bad, I should have stated that the wheels assist in the general balance of the bicycle. To test if the wheels act like a flywheel, hold one by the axel. Tip the wheel left to right, easy eh? Now spin the wheel as it would normally roll, (or have someone do it for you, the faster the better) and push forward with your left hand. The wheel now has some resistance and will tip to the left. This experiment shows the gyroscopic effect and the right hand rule of rotational mechanics.

An excellent article on the dynamics of bicycle balance was written by Davie Jones, Ph.D, some of which can be found in the April 1970 edition of Physics Today. He tried to produce a bicycle so unstable as to be un-rideable. In one experiment he introduced a second wheel that did not touch the ground but was side-by-side with the front wheel. His theory was that he could cancel out the stability of the bike by spinning it opposite of the front wheel. Though it did not de-stabilize the bike when spun backwards, when spun forwards in sync with the front wheel, the bike became even more stable. This allowed it to travel without a rider in a straighter line and further than normal. He found that by changing the pitch of the fork, even to reverse it created an unstable device. Otherwise he changed the center of gravity.

Other factors that help balance the vehicle is the pitch of the front fork in relation to the frame, the angle of the frame in reference to the whole (with or without rider(s)), and the center of balance. All of these add together to create a simple, but remarkable stable device.

The (sometimes way to general in his statements) Don


Radiatidon
Posted 19 October 2007 at 08:06 am

Silverhill said: "Greetings, "Don Radiati"! Excellent, informative response, as usual. However, there's one teensy factor-of-500 error there. Human hair averages 99 micrometers in thickness (range: 17 - 181 micrometers), or 99 000 nanometers. (This makes the distance-of-travel of that weight even more impressive in its tininess!)
Cheers,Silverhill"

The Don lifts his tin-foil hat up and plucks a hair from his balding scalp. Placing the sample on a slide, he covers it with a thin piece of glass and places the whole under an electron microscope. Grabbing a magnifying glass, he adjusts his thick bifocals as he squints, all the while examining the dander encrusted, split-ended hair on the 105”, HD, Flat screen monitor.

Grabbing a right triangle, a well-worn slide rule, a t-square, a clear plastic ruler, and an old TI-30 he goes to work. Reaching into his mouth he extracts a wad of gum, which he uses to attach the t-square and clear plastic ruler to the monitor.

Mumbling incoherently he slides the right triangle across the t-square and clear plastic ruler. Taking the slide rule he makes some quick calculations then double checks his figures with the aging TI-30 calculator.

“Aw crap.” He mumbles while prying the t-square and ruler off the monitor with a wet “pop”, he wipes the screen with the sleeve of his lab coat leaving rainbow-hewed streaks across the surface. Absentmindedly he pops the dust encrusted gum back into his mouth while shutting off the equipment. . Happily chewing away, he begins to type at the computer keyboard.

Okay, an atom is around 0.0001 microns thick. A human hair is around 100 microns thick or otherwise 1,000,000 angstroms thick. Looks like I dropped a decimal point.

Big deal…

He pauses, collecting his thoughts. With a quick feint he changes the subject hopefully catching the others off guard. Perhaps they would forget this stupid mistake.>

… what really is important here is why does Bubblelicious taste dusty shortly after you start chewing it. Like the piece I’m chewing now, has a sort of metallic-dirt taste to it. Now that is something worth discussing, eh?

With a knowledgeable smile, the Don leans back in his well-worn leather chair.

Thanks Silverhill for humbling me but again. ;)


HiEv
Posted 20 October 2007 at 10:34 pm

Dare we mention that he misspelled "Bubblicious"? ;-)


Anonymousx2
Posted 22 October 2007 at 04:33 am

Last.


God
Posted 02 November 2007 at 01:00 pm

Mechanical women is what we need................


SoxSweepAgain
Posted 03 November 2007 at 06:47 pm

I think this would make a spectacular groundlaying of physics for the "Flying Saucer" idea.

Not to mention that if gyroscopes are spun up to a high enough RPM, they actually cause gravitational displacement (e.g. the vehicle becomes lighter).

If sufficient gyroscopic activity were able to be manufactured, could not a spinning super-dens, super-strong flywheel not just lift and propel a vehicle, but also serve as a lightest-touch steering system?


Graniteback
Posted 06 November 2007 at 11:25 pm

Goodtwin said: ""and today it’s under the hood of every automobile on the road, performing the same function it has for millennia—now regulating the strokes of pistons rather than the strokes of a potter's foot."

"No, actually flywheels are only used in some cars, those with manual transmissions. There's a thin flexplate in an automatic transmission or transaxle"

The reason that flexplates are used in automatic transmission applications is that the torque converter provides the mass and weight required to dampen engine pulsations and provide centrifugal force to keep the crankshaft rotating between combustion strokes. The torque converter, in most applications, is bolted directly to the flexplate.
The counter weights on the crankshaft assembly are used to keep the rotating assembly from vibrating (they counterbalance the piston/connecting rod assembly), not to dampen engine pulsation or maintain rotation. The crankshaft stays the same, regardless of whether there's a flywheel or flexplate bolted onto it.

Great article, keep up the good work.


Radiatidon
Posted 07 November 2007 at 10:37 am

Graniteback said: "No, actually flywheels are only used in some cars, those with manual transmissions. There's a thin flexplate in an automatic transmission or transaxle"

The reason that flexplates are used in automatic transmission applications is that the torque converter provides the mass and weight required to dampen engine pulsations and provide centrifugal force to keep the crankshaft rotating between combustion strokes.

Thus the torque converter is a flywheel by its very operation. ;)

Actually the flexplate is more commonly referred to as a flywheel.

AutoZone Flywheel (Automatic Transmission)

Makco Distributing, Inc, Automatic Transmission Flywheels

This page has photos of both automatic and manual transmission flywheels -- Ford Racing Performance Parts

Though not massive like a manual transmission’s, it still acts as a flywheel in assisting the starter in powering up the motor. In an automatic transmission, the power surge due to the pistons is handled by the torque converter (once referred to as the fluid flywheel). This bell or round throw-pillow shaped device uses the pressure and weight of hydraulics to transfer power from the motor. Also due to its design, with the fluid rotating around the inside of the drum, it acts as a flywheel to help dampen vibration.

How Stuff Works

So regardless, both the manual and auto transmission vehicles utilize one form or another of a flywheel to both help start combustion and dampen power surges.

It should also be noted that a flywheel by design is not just a storage medium for energy, but also a potential energy converter. You see it also acts as an amplifier for power transmission due to the distance of travel of the outer hub in relation to the distance of travel of the axis. This multiplies the torque power of the electric starter to help keep it small and efficient enough to move all the parts of an engine to promote ignition. On the flip side the flywheel dynamics allows the axel to move a vehicle by providing a relatively low rotation in relation to the wheel’s outer edge, high rotation index, in contact with the road surface.

The Don


Radiatidon
Posted 07 November 2007 at 12:42 pm

Whaaa…

I just got an e-mail telling me that my hyperlinks don’t work.

Humph, the site messed-up my hyperlinks. When you click on them, it adds http://www.damninteresting.com/%E2%80%9C in front of each.

So here they are in their entire, expanded, glory.

AutoZone Flywheel (Automatic Transmission) -- http://www.autozone.com/az/cds/en_us/0900823d/80/04/ad/93/0900823d8004ad93/repairInfoPages.htm%E2%80%9D

Makco Distributing, Inc, Automatic Transmission Flywheels – http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=flywheel%E2%80%9D

Ford Racing Performance Parts -- http://www.fordracingparts.com/parts/category.asp?catID=41&catdesc=Flywheels%E2%80%9D

How Stuff Works -- http://auto.howstuffworks.com/torque-converter2.htm%E2%80%9D


Jeffrey93
Posted 18 November 2007 at 10:55 pm

I don't know about you guys....but I'd feel a little iffy getting into a vehicle that has so much built up energy. Would it be efficient? Yup. Would it be clean? Yup. Would it tear you and anyone around you to total shreds if anything went wrong? Yup.
There are so many issues with this I don't even know where to start. One thing to think about is to realize who would be building these Fly Wheel Cars. Car companies. No way am I going to trust those doods to build something that would have to be perfect....every time. A microscopic fracture could end several lives; I should trust Ford to make sure that won't happen?
Ever had fuel pump problems? A stuck accelerator? Imagine problems like that with a Fly Wheel car. You could be picking the kids up at school and you're suddenly rocketing through the school yard at 230mph due to a malfunction.
It all seems too risky for automobile use, there are many many other potential uses though....hopefully those can be realized to limit our dependence on fossil fuels and decrease pollution.


HiEv
Posted 19 November 2007 at 06:30 am

Fortunately, driving around with a tank of gasoline is quite safe, right? ;-)


da5id
Posted 30 November 2007 at 12:32 pm

Well, this is a damned interesting article. But I was wondering about the the superconducting necessity. Does anyone have any efficiency and energy usage numbers for maintaining a superconducting bearing? It has suggested by my physics professor that "cheap" room temperature superconducting technology would be as great a technological revolution as computers have made in the last, say, 50 years. Is the superconducting requirement almost like the tail wagging the dog in the context of a flywheel discussion?


Jeffrey93
Posted 12 December 2007 at 12:15 am

HiEv said: "Fortunately, driving around with a tank of gasoline is quite safe, right? ;-)"

I can stop the combustion of gasoline in my car, I'm not sure how I could stop this built up energy from releasing whenever it wants after some sort of failure. The properties of petroleum can be dealt with....this is just raw energy that needs to be released at some point and in some manner. If my fuel pump malfunctions I can turn my car off, if something similar would malfunction in a car utilizing a flywheel.....I'm not so sure you could stop the release of energy that easily and safely.
If a car's accelerator sticks you can put the car in neuteral or simply shut it off.....a similar failure in a car like this could be catastrophic.


HiEv
Posted 12 December 2007 at 06:21 pm

Jeffrey93 said: "I can stop the combustion of gasoline in my car,"

OK, I'll toss a lit match in your gasoline tank and you stop it. ;-P

Jeffrey93 said: "I'm not sure how I could stop this built up energy from releasing whenever it wants after some sort of failure."

It depends on the kind of failure, but the obvious answer is to apply the brakes in some way, i.e. convert that momentum into some other kind of energy that can be released safely.

No system is perfect, so the question is whether this system is substantially worse.


Wingnut
Posted 22 December 2007 at 10:44 pm

Long ago I convinced the company I worked for to buy an early form of flywheel power. But it was designed to provide totally clean power for computer equipment that was very sensitive to its power input. It was called a motorgenerator, an electrically powered electrical generator. By completely isolating the power by mechanical means, no power glitch could be passed through. It incorporated everything needed for a flywheel system except it only would last a fraction of a second if input power was lost. Had it incorporated more mass into the spinning generator, it could have provided what ever stand by power that was needed. At many computer installations I have worked at, the battery systems were designed to last just long enough to bring a diesil generator online. In this case a small flywheel could provide the power and replace the expensive battery systems that decay over a few years (and typically used lead batteries, something that is not too green.)

I remember a recent company that already had the diesil generator surrounded by a concrete enclosure. Had it been a bit thicker, it would probably served as a containment wall as well. Given the amount of money spent on large computer complexes, using a flywheel system might be more than cost effective with current technology, and certainly a 'greener' solution than using diesil. While a fuel powered generator can last indefinately, in actual practice you seldom need that long. If the power is out for days, other problems will probably make running a computer complex difficult anyway. The last power failure I personally experienced at a computer center was caused by contruction down the road a block hitting a buried power cable. This only required a few hours to fix.

This use for computer installations might prove a good way to introduce the concept and technology, especially with companies trying to out "green" each other. Announcing a system that didn't use diesil and lead batteries would be good press, and might even get some kind of tax credit.


Wingnut
Posted 22 December 2007 at 10:58 pm

Many companies in Southern California are putting solar power arrays on their roofs. Since peak power demand is a big problem in California, providing power during the day when air conditioning is in heavy use works great. Also note that peak power can cost much more than off peak. Flywheel storage systems could potentially be charged by both solar and off peak power to use as required. I have heard that many factories in California are installing generators since the loss of power can be very expensive for operations such as semiconductor fabrication. Having enough flywheel standby power to finish any given run would be great. The "green" aspect and possibly much lower operational costs may prove atttractive if someone could package up a commerical grade system.

Then again, I would not mind my own 27 megawatt nuclear generator. See
http://blogs.abcnews.com/scienceandsociety/2007/11/a-nuclear-react.html
and their home page http://www.hyperionpowergeneration.com/

Imagine a complete system that can fit on a truck!!


Chazzychuckles
Posted 20 March 2008 at 12:17 am

Why cant a fly wheel be made up something less deadly. For instance a liquid could easily be encapsulated in such a way that it would be the mass of the fly wheel yet designed to fail much more safely. It seems to me that the stronger faster and heaver you make something the deadlier it is. A broken flat 4in piece of a spinning flywheel traveling like lets say 400mph is a decapitating Frisbee 200ft later its still a 4in decapitating Frisbee. water spinning at that speed would continue to pull itself apart until its nothing but vapor. Perhaps if flywheel broke, the liquid would just continue to rotate in its containment vessel with friction slowing it down. Rather than a explosive force you get heat. Just a thought...


bobchr
Posted 24 June 2008 at 08:52 pm

HiEv said: "Smaller flywheels dramatically lose effectiveness. Keep in mind that if you halve the size of something, you end up with 1/8th the volume. So, smaller flywheels have a fraction of the mass, meaning less energy can be stored, and are likely much more fragile, requiring slower speeds for safe and reliable use. Those two things combined mean that one large sturdy flywheel is almost always better than multiple smaller ones taking up the same volume, at least in terms of efficiency and maximum power storage."

I'm not so sure about this, while you may be right about the volume and energy estimates, experiments in nano mechchanical technology suggest that using current integrated circuit manufacturing techniques you could make millions of counter rotating flywheels with a network of charge and discharge conduits on a thin wafer. Imagine a few hundred thousand flywheels on a silicon wafer the diameter of a quarter. A 100 micron size flywheel made of Silicon may only be able to store nano joules but 100,000 in paralel bring you to millijoules. Stack a thousand of these wafers together and you're in the 1 joule area in a size smaller than a D cell. Computations can be done using the atomic mass and density of silicon and calculate the potential energy storage as a function of rpm. I don't have a periodic table handy but I don't think my guestimates are too far off.
That small, any platter can easily support 100,000 to 500,000 rpm for long periods of time. Oversized magnetic bearing can be designed into each individual flywheel by proper doping. Voltage limits could be places on each wafer to limit speed and current would be controlled by the number of flywheels in parallel. A standard cell could be mass produced and the interior would be vacuum sealed to ehnance longevity.
Nano sensors are designed into the accelerometers that trigger airbag systems. Similar concepts using peizioelectric energy to boost magnetic confinement in the bearings and counteract inertial disturbances in individual flywheels is a possible approach. Stacking standard cells would allow you to customize your power needs. A lot of AA sized Li ion batteries go into making up the laptop batteries that are currently on the market. And a lot of laptop size battery stacks are going into making batteries for electric cars.
With the proper motivation a nano machine company could probably bring such a device to market within 2 to 3 years. Imagine AA cells with 5 times the energy density. Safety could probably be enhanced by surrounding the vacuum sealed outer shell with a gel coating. These systems could probablty be designes to withstand 200G shocks. Like microscopic capillaries that can pump 100's of gallions of water to the top of 200' high redwoods in nature I think the answer here may not be to go bigger with more mass but to integrate many smaller masses.


bobchr
Posted 24 June 2008 at 09:14 pm

Wingnut said: "Many companies in Southern California are putting solar power arrays on their roofs. Since peak power demand is a big problem in California, providing power during the day when air conditioning is in heavy use works great. Also note that peak power can cost much more than off peak. Flywheel storage systems could potentially be charged by both solar and off peak power to use as required. I have heard that many factories in California are installing generators since the loss of power can be very expensive for operations such as semiconductor fabrication. Having enough flywheel standby power to finish any given run would be great. The "green" aspect and possibly much lower operational costs may prove atttractive if someone could package up a commerical grade system.

Then again, I would not mind my own 27 megawatt nuclear generator. See
http://blogs.abcnews.com/scienceandsociety/2007/11/a-nuclear-react.html
and their home page http://www.hyperionpowergeneration.com/

Imagine a complete system that can fit on a truck!!"

There is already a company doing this. It is listed on the OTC exchange with the symbiol BCON. The name is Beacon Power Corp. They manufacture and integrate mechanical flywheel batteries in to multi-megawatt power plants that are designed to stabilize the grid. They boast being able to respond to grid demand fluctuations in seconds rather than hours the current systems of auxillary generators can take to respond. This slow response time is usually the cause of brown outs. Beacon Power has construced demonstration plants using nothing but flywheels. They would buy cheap hydroelectric power from upstate New York at night during low demand hours for say 4 cents per KWH and sell it back to the grid at double the price during the peak daytime hours. Almost no PM for these 16,000 rpm 7' tall by 3' diameter mechanical batteries.


bobchr
Posted 24 June 2008 at 09:27 pm

cinndave said: "Completely unnecessary. If you have solar panels, windmills, waterwheels, etc. on your property that's generating more electricity then you're consuming, the surplus is fed back into the grid and your meter starts to run backwards. By law, if you feed more electricity into the grid than you draw, the electric company gives you a check instead of a bill. Little known fact, but it's true!"

If you're not connected to the grid , say you live in the northern most part of Moose jaw Canada. Are you planning to watch TV only when the wind is blowing or the sun is out? Flywheel systems even out the process by storing the excess for later consumption. That far north your sunlight is only a few hours per day in fall and winter. If you are connected to the grid what keeps the power company from tapping your sources during high demand periods?


macrumpton
Posted 19 September 2008 at 07:51 am

A couple of thoughts:
If both the flywheel and container were sphere shaped , the flywheel could tilt without any resistance assuming you can still magnetically levitate it . Also a sphere is a good shape for distributing stress, so it could help make both the flywheel and container sturdier.

If you make the flywheel out of materials that can store electrical energy like a battery or a capacitor (carbon nanotubes are promising) then the density of the energy it can store goes way up, because it is both a battery/capacitor and a flywheel.


macrumpton
Posted 19 September 2008 at 08:02 am

For a non mobile application where you can safely bury it underground a flywheel seems pretty attractive. Since size would not be an issue you could have the flywheel much larger and slower for a better safety factor. With a big slower flywheel the tricky part is the bearings, but without the erratic stresses of a moving vehicle the bearings could be fairly simple.


jski
Posted 06 September 2009 at 11:52 pm

magkneetoe said: "How about a flywheel battery for my phone…

Somehow I dont think that would work."

Actually, we have been using that technology for some time now. Good examples are self-winding and self-charging watches.


jski
Posted 07 September 2009 at 12:07 am

By the way, a kinetically charged phone would be a billion dollar idea. I hereby donate the concept to humanity, asking only for a pittance (say 2%) if such an idea becomes a gold mine for someone else. Unless tomorrow I decide that it really is a good idea, and go patent it. There is a size issue, but I have seen novelty phones that were quite small, so there is some room in a more standard phone design for a flywheel. Make the battery smaller, since it should be getting recharged more often, and... well it might work.


vxcriss
Posted 09 April 2010 at 12:41 pm

The flywheel is naturally flawed. It's biggest problem is that it constantly looses energy thus it does not make for a good storage device. I have thought of something much better that does not loose any energy and it is based on a really simple principle which has also been used throughout the history but somehow seams to have been forgotten in the modern age. Check out the illustration at http://www.GravityBattery.info


cinndave
Posted 13 September 2010 at 08:43 am

Hey look! Porsche is now using flywheel batteries in its race cars. The flywheel hybrid battery's time has come. This is exciting!

http://www.jaylenosgarage.com/extras/extras/pebble-beach-2010-porsche-motorsports/


oliverioism
Posted 06 November 2010 at 07:01 am

Im all about alternative energies like this! The Gravity Battery (above) is definitely the best way to store energy on a large scale. But Ive been thinking about using wind up coils and springs for more portable small scale energy storage, say, for a laptop


Oliver
Posted 28 August 2012 at 12:08 pm

Concerning Flywheels in hybrid cars, this might be an interesting read:

http://inhabitat.com/porsche-unveils-911-hybrid-with-flywheel-speed-booster/

I could find no other articles in english language.

In short, that Porsche uses a 2-disc flywheel concept. The difference to other flywheels is that the flywheels are made from carbon fiber that has been loaded with metal particles. Coils and stuff are positioned around the flywheel housing. So when the car brakes, it generates electric energy using two motors/generators in the front wheel hubs. This electric energy is then stored in the flywheel by accelerating it like a rotor in an electric motor.
Vice versa, when accelerating the car, movement energy stored in the flywheels is used to generate electricity for the front wheel motors/generators.

The advantages are that no clutches etc. are connected to the flywheel and thus it is much easier to keep the flywheels inards evacuated.

Furthermore, in case of a crash, one of the two flywheels is generating energy which is then used to stop the other flywheel. As far as I remember, the flywheels can be stopped in about 0,1 seconds with no damage done.


Ann
Posted 17 November 2012 at 01:49 pm

Hay Guys this article has been totally interesting. I have zero technical know how but could some one tell me if an idea I have been toying with, and found your site trying to find information about, where excess solar etc. power could be stored on springs like a clock. Is that a completely infeasible, or impractical possibility?


Glow Fish
Posted 06 December 2013 at 11:44 am

Seriously? This doesn't seem like a step backwards? I'm mean a big spinning heavy thing has it's place, but it's not on a vehicle for efficiency reasons. Like a good place would be a back up generator station or emergency power for critical systems.


Adam
Posted 14 December 2013 at 12:46 pm

I think its possible to put permanent magnets on the peripheral and make a stator housing around it so you can save the kinetic energy and still constantly generating electricity even powering itself if it starts to slow down.

Caveat Emptor: Anyone who *doesn't* believe in perpetual motion is quite possibly insane, since he can't point to single solitary instance of anything standing still.


Gary
Posted 27 August 2014 at 12:20 am

It's not simply stagnancy.
Large corporations purchase rights to new technologies that threaten their profits. They then shelf the technology and continue business as usual. It is frequently more profitable -- or safer -- for them to keep the technology shelved indefinitely rather than putting it to use in creating a new product or improving an existing product. The technological advancement of our societies is being tremendously stunted by corporations and military organizations who hide new technology from the public.


Tony
Posted 02 September 2014 at 06:07 am

Hehe this sure is interesting. In the tablet/phone game "Blockheads", you can craft flywheels which acts as energy storage units. I thought it was kinda silly at first, like why didn't they use something more conventional like a battery, until I read this article.

Cool stuff.


chris
Posted 28 September 2014 at 05:05 pm

Radiatidon said: "jbigdog said: "Flywheel technology seems like it would be a great way to enhance solar. Imagine a home with a big, buried flywheel out back with a solar panel hooked up to it. Then you don't run into down time issues on a cloudy day, or at night. Wind works, too. Can anyone think of a reason that wouldn't work?"

To my mind, cost and maintenance issues are the only factors.
First you would want multiple flywheels (about the size of a standard auto wheel, give or take). This way you have a redundant system should any fail, so you don’t end up with zero power. Also smaller flywheels lose kinetic energy faster than a larger one, that way should they ever get loose, the smaller ones would cause less damage than say a massive car-sized one. Not to mention that it is easier to move and replace any parts on say a 150-pound metal wheel than a one-ton plus metal wheel. You have to keep in mind though, the more parts to a system, the higher the maintenance and the more components that can and will fail.
Next you would want the system stored in a somewhat climate controlled area. This ensures a longer life span for the various components (rust and dirt cause friction which decreases your system’s efficiency). A hardened concrete structure would be best with a positive pressure system (filtered air blown into the structure so any dust/dirt is blown out when someone enters). Sort-of like those old bomb shelters they built during the 1950’s thru 1960’s. That way if there was a mount failure, and the safety brake (a marriage between both a friction brake and a magnetic braking system) failed to slow/stop the flywheel it would just rebound (hopefully) within the enclosure (each flywheel in its own room to decrease chances of it damaging the other systems).
The system would need to be designed so that your power usage will never cause the flywheels to drop below a certain RPM. The initial cost in energy to start the wheels moving from a dead stop is over three times what is needed to keep them spinning.
Without sitting down and doing some serious math, I’m not sure of the size required for a solar array to power the system. I do know that a well can use a 12-volt pump that runs continuously filling a gravity reservoir (water tower). That way when you use water, the pressure is not created by the pump but by the weight of the water in the reservoir and gravity pulling it downward. This system uses a small array and is cheap to replace when the motor wears out, and not to mention that the power to run it is free.
Living on a ranch, we incorporate two systems for our water usage, the low voltage system for daily use by animals and people, and both a 120 and 240-volt system for irrigating pasture and vegetable/fruit gardens. Though I have slowly been converting the crops into a low volume watering system and might be able to convert that well into a multiple low-voltage pump system. The system(s) only need to be designed by the GPM one may use on a peak day. Free sunlight and wind power is cheaper than corporate generated electricity any day of the week, as long as you perform preventive maintenance religiously.
Not a bad thought though."

not saying change the floating sides to help on turning, but couldnt you take the air intake from driving car or plane and use water inside the device to spin? yes it would weigh a little bit more than metal but would be cheap and easier to replace.


sedacca
Posted 28 October 2014 at 10:20 am

I remember seeing a half megawatt flywheel well embedded in a concrete pit at Falcon Testing Laboratories in Loughborough near Leicester, some ten years ago.

I don't know if it was still operational then - it was certainly not used for the very high prospective fault currents that we needed to test the circuit breakers used for electrical distribution switchgear.

I suspect they would have dumped the current to earth as heat through massive resistor banks. I somehow doubt that they would have been able to use batteries to store the energy.

Before that pre-2000, I went to an all-electric ship conference where some navy bods were talking about the possibility using flywheel storage instead of batteries, but I don't know if this ever came to fruition.


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