crasch (crasch) wrote,

Flywheel battery

From: (
Subject: Re: Flywheel power for real

View: Complete Thread (24 articles)

Original Format
Date: 1994-02-05 08:14:57 PST
In article <2in6kb$>, (Lee Devlin) writes:
>I came across an article in the most recent issue of IEEE's Spectrum
>that I thought would be of interest to this group. I'm posting it here
>after reading a lot of misinformation and confusion about the
>feasibility of flywheels to store energy for EVs recently. I can't
>attest to the accuracy of the claims so don't flame me if you
>have a disdain for EVs and categorically attack any data which shows
>EVs or related technology in a favorable light :-).
>From p. 62 of the Jan. 1994 issue of IEEE's Spectrum:

This is really just a derivative article that doesn't really
answer _any_ of the criticisms that continue to be leveled at
the electromechanical batteries. About a year ago I posted to this
group the first IEEE Spectrum article " A Different Spin on an EV
Battery" November 1992 p100. It also included the picture. This
discusses Richard F. Post's EMB, which has been the main model
under discussion.

Much of the problem then ( and now ) is that readers assumed
only one flywheel, when in fact the proposal by Post was for banks
of them. The AFS systems uses counter-rotating flywheels.

The more comprehensive article about the EMB was written by the
inventor, and appeared in Proceedings of the IEEE v.81 n.3 March
1993 p.462-474. "A High-Efficiency Electromechanical Battery"
Richard F. Post, T.Kenneth Fowler, and Stephen F. Post.

This answers many of the criticisms _because_ it discusses many
of their design criteria. It doesn't answer the criticism that
no vehicle EMB exists, but it does show that almost all the
arguements raised in over the last 15 months were
considered during the original design. I posted a fairly
extensive listing of the EMB data in this article about the
middle of 1993.

Another article that is more general is " Flywheels put a
new spin on Electric Vehicles" by Steven Ashley in Mechanical
Engineering. Oct 1993 p.44 - 51. I've also posted some of
the data and comments in this article - it contains some
good expert opinions on the EMB. It also discusses the
the AFS EMB, and notes that July 1995 is the date in their
plans for the construction of a flywheel energy-storage vehicle.
Your quote moves that out to end of 1995. It seems that AFS
have made a flywheel, as had Post by the time of the Oct article.
( his is apparently for computer backup power supply - a stationary
application ) It seems AFS have also produced a stationary one.
There is quite a way to go to make a vehicle run, with road shock
and gyroscopic forces being major problems discussed in the above

Anyone interested in the EMB should at least read the article
by Richard F. Post. One problem with Usenet is that once the
regulars have been through the first few iterations of a repeat
thread ( EMB have been through at least 4 major threads in the
last 15 months ) they tend to start flaming. I think the above
articles indicate what the actual claims are for EMBs.

There are several other firms actively pursuing EMBs, and the
Mechanical Engineering article discusses each. I think it's
important that readers realise there are several competing designs,
and they all are issuing publicity information. The article you
quote has all the hallmarks of a publicity release. Using the
GM Impact as an example indicates that, especially since the
article notes that Detroit isn't wildly interested. The Impact
( like the GM IC-powered Ultralite of similar Cd ) is a experimental
vehicle built with future production in mind, it's not designed
for EMBs.

Bruce Hamilton
  • Post a new comment


    Anonymous comments are disabled in this journal

    default userpic

    Your reply will be screened