“Extreme” Plug-In Flywheel Hybrid Promises a Possible 250 MPG - GreenHybrid

Jason · #1 (**permalink**) 02-23-2005, 01:55 PM

Quote:

AFS Trinity Power Corporation has unveiled a flywheel-supported hybrid technology that the company anticipates will enable fuel economy in the 200–250 mpg range.

The Extreme Hybrid drivetrain—under development for light duty and heavy duty vehicles—is a plug-in hybrid that gets most of its power from the grid. The flywheel system provides greater efficiency in energy capture and release from regenerative braking, thereby extending the operational range of the vehicle in all-electric mode.

- http://www.greencarcongress.com/2005...xtremerdq.html

Hot_Georgia_2004 · #2 (**permalink**) 02-23-2005, 05:43 PM

Last year I did quite some research on flywheel energy storage devices. They are truly fascinating in the right application.

Flywheels work wonderful as short-term power backup systems for computers, etc, they can even supply temporary backup power for entire buildings, provided the mass is large enough, and how many are employed.

There have been quite a lot of research in flywheel powered cars for years, here are just a few "roadblocks" they have encountered:

1. In order to achieve a 100 mile traveling range it would need to store enough kinetic energy that if it were released all at once in an upward fashion, would hurl a ~3Klb vehicle around 10 miles straight up.
2. Flywheels occasionally fly apart. It's usually quite a large explosion when the incredible energy is suddenly released from a larger one. In order to ensure safety these large units are installed in the ground.
3. The flywheels do not rotate on ball bearings. The bearings are magnetic and provide zero resistance because the shaft "floats" in a magnetic field. Even if mounted in a gimble it is not enough to overcome the shake of an automobile, as this magnetic field is compromised.
4. In the case of an automobile accident, there is real danger of a heavy flywheel becoming unstable and exploding, causing further injury, death and/or destruction.
5. Please forgive, but I've forgotten the techical name for the nature of a Flywheel to resist crosswise rotation. They've used this property for decades in guidence systems, etc. This was another problem they found associated with flywheel powered autombiles.

I admit not reading the article with its technical descriptions, as I don't really want to register at that website.
I know the flywheel in this car isn't its only power source but I find it hard to believe that they have overcome all the related problems well enough to provide a safe vehicle.

Guess this is a "Just wait and let's see" kind of thing.

tbaleno · #3 (**permalink**) 02-23-2005, 07:15 PM

Is a flywheel similar to the thing they put in wind up toys?

Hot_Georgia_2004 · #4 (**permalink**) 02-23-2005, 07:39 PM

Not wind up, that would use a spring.

A spinning top is an example of a flywheel.
My son had a flywheel based car that you put in a base and turned a crank, spinning the wheels faster, faster and faster. The flywheel inside would make quite a noise as it spins to store the energy from the crank. Then you'd let it go and it zoomed across the floor.

Commercial flywheels are sealed in a vacume of special gas to reduce friction, made of a composite material and as mentioned uses special zero friction magnetic bearings. These flywheels used for energy storage range in size from about a foot square to much, much taller ones.

Probably the most widely used flywheel storage sytem is for computer power back-up system. Typically it would provide enough time for a proper shut down of many computers connected in a network.

The idea is to use an electric motor to gradually spin a heavy flywheel up to speed, then maintain that speed. Imagine 50lbs or so spinning at several hundred thousand RPM's.
When the power goes out the motor converts to a generator (Like our cars electric motors do) and runs the backup system for computers, etc.

If you do a google search on flywheels the reading can be fascinating.

clett · #5 (**permalink**) 02-24-2005, 02:33 AM

Other than the safety issues, the other downside to flywheels is the low specific energy (ie you'd need a heck of a large flywheel to give a car any real range).

AFS appear to be using them for their peak-power benefits though, to take the strain off the batteries (though I think ultracaps would do a better job of this and keep things a lot simpler).

mastersgtbob · #6 (**permalink**) 02-26-2005, 10:22 PM

If you can windup a radio for about two mintues and it will play for about an hour. Is it possible that this could work on a Hybrid?
But only as a backup. Lets say you forget to check your gas gauge and you don't have enough gas to make it to a gas station. The rule I read is don't drive your Hybrid, on the battery without gas in the tank. If you had something like a windup, this could be enough to get you to the nearest gas station.