Power    and

Comparison of RPM Technology with Others


Flywheel Battery:

The RPM flywheel battery is far different from any others, mainly due to its low storage (idling) losses, zero maintenance, and unlimited service life.  It could serve a vast need for practical environmentally-responsive power storage.  Rotational dynamics, magnetic fields and forces, power electronics, advanced materials processing, and system integration, are a few of its most important elements. 

It could provide safe, stationary, on-site UPS (Uninterruptible Power Supply).

Parallel connection of 2 or more flywheel battery systems will accommodate a variety of  power storage needs with one model, and dramatically increase UPS reliability. They can supply power for days, and can store it without much self-discharge for months.

Other flywheel batteries supply power for only seconds or minutes, and self-discharge in hours. Their motor/generator's ball bearing and magnetically cycled iron core losses are partly responsible. 

Others enclose flywheels in heavy and costly enclosures, intended to contain a possible explosion. The RPM flywheel battery would be normally installed in an underground site that can safely absorb a maximum energy, rapid discharge flywheel explosion. That precaution is crucial, even though such an explosion is very unlikely. 


Left::  Image of RPM flywheel battery in a self-leveling underground installation.

Its support is self-leveling.

Its large volume underground surroundings are designed to absorb energy without much temperature rise.





Regenerative Motor:

Left photo below: Fradella developed this brushless DC regenerative motor about 40 years ago. Demo includes motor responsive to speed/braking control, power electronics that includes battery charger, and 48vdc battery pack.

Right photo below: Motor parts before assembly. It has no core loss. It has no cogging torque. It has stator winding losses of about 1%. Its power electronics has losses of about 5%.  It is scalable, depending on the number of disks in the motor assembly and its power electronics' rating.

An outside rotor version can enable motor-wheels for ultra-efficient electric vehicles (EVs).


Broad-speed-range generator:

The RPM broad-speed-range brushless DC generator can produce about 100x the energy yield of conventional wind turbines and generators, for about the same cost. It has integral boost-regulation switch-mode power electronics. Its DC output power is current and voltage regulated, and able to maximize power from wind turbines over a wide speed range. Power quality is far better than others. Especially compared to induction generators in wind farms.   

A lab photo of our generator, charging batteries, driven by a variable-speed test motor, is shown below.


EV with onboard PV:

This EV would be solar powered in daylight, by PV (photo-voltaic) coating on top surfaces, and have an optional onboard generator powered by recumbent cycling pedals that offers a healthy time-saving exercise option while extending the EV's driving range, speed, and ability to travel without sunlight. Its onboard battery replacement cost would be only a few % of that for other EVs, because its batteries would normally not be discharged while driving unlimited distances at average 50-mph speeds, so they would normally last 10 years vs. about 2 years in other EVs.

This EV would need only about 10% as many onboard batteries as other EVs. No fuel stops !!   No stops to charge its batteries !!

An image of this EV and 1 of its 2 rear motor-wheels is shown below:



If you have questions, comments, or suggestions, email

Aug  2015