[Christoph (Unverified) Posted Jun 20th 2008 6:09AM]

@ Tim Buck Too,

the amount of stored energy increases with the square of the rotational speed - that's why they are using carbon-fiber wheels to allow the weights at the circumference to spin at extreme high speeds of about 18 to 20,000 rpm.

This allows the wheel to be lighter and more responsive - in fact you can take high amounts of energy from the system without time delay.

The guys with the earlier comments are correct with the principle of pumping water to higher reservoirs to generate energy at peak times called Pumped Storage Hydroelectricity (PSH), similar to using flywheels. However, utilizing flywheels has significant advantages:

1. location: need a mountainous, rocky area suitable for water storage with large height differentials. These are mostly found distant from metropolis (important as you see below). Flywheels: install in any warehouse.

2. expense: extremely expensive and timeconsuming to built PSH. Flywheel: no so

3. efficiency: PSH have smaller efficiencies because they convert energy multiple times: electrical - mechanical - pressure - potential -> dynamic and pressure - mechanical - electrical. Every time a art of energy is lost to heat vibrations, etc. This adds up to a high loss. Flywheel: electrical - dynamic -> electrical energy. Much smaller losses

4. scalable: buy one flywheel for your house or thousands for the energy plant.

5. near end user: electrical energy has high loss in transmission over distances. Flywheel farms can be built exactly where the demand is.

Disclosure: I have nothing to do with Beacon, except I own the stock because the technology makes a ton of sense to an engineer like me!

Best of luck. Christoph