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- From: carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick)
- Newsgroups: sci.electronics,sci.energy,rec.autos
- Subject: Re: Flywheel batteries as EV power source
- Date: 28 Dec 1992 20:40:28 GMT
- Organization: HST Wide Field/Planetary Camera
- Lines: 48
- Distribution: world
- Message-ID: <1hnonsINNnna@gap.caltech.edu>
- References: <etc.> <1992Dec22.204130.18133@enterprise.rdd.lmsc.lockheed.com>,<1992Dec23.015933.24919@erg.sri.com>
- Reply-To: carl@SOL1.GPS.CALTECH.EDU
- NNTP-Posting-Host: sol1.gps.caltech.edu
-
- In article <1992Dec23.015933.24919@erg.sri.com>, rat@erg.sri.com (Ray Trent) writes:
- =Is anyone here missing the point that flywheel powered cars need far
- =less total energy to go a certain distance (stop and go) than a
- =gasoline powered car?
-
- No, nobody's missing the point, but you seem to have missed a lot of the
- discussion. The people touting these flywheels are talking about a car with a
- range of 600 miles, though they plan to divide it up among 20 flywheels,
- something that wasn't mentioned in this thread until a couple of days ago).
- Now, we've been talking about the energy required to drive a car 100 miles at
- freeway speeds, and one of the more fuel-efficient cars on the road today, to
- boot. I.e., we've been talking about roughly 2 gallons of gasoline. Now, if
- the people touting the flywheel technology are really trying to mislead us and
- they're talking about a 600 mile range at an average speed of 15 mph, then yes,
- you might have a point.
-
- =Car designers aren't completely stupid, you
- =know, they do try to recover kinetic energy during braking in a
- =vehicle that is capable of doing so (gasoline engines aren't).
-
- If they're talking about stop-and-go driving, why are they talking about a
- 600-mile range? The two just don't seem to go together somehow.
-
- =Also,
- =flywheel vehicles aren't really intended to provide as high a range as
- =gasoline powered vehicles, nor are they intended to be used for
- =towing. We're talking commuter cars here.
-
- The people touting the vehicles said a 600-mile range. That sounds a lot like
- as high a range as a gasoline-powered vehicle to me.
-
- =Additionally, gasoline engines are basically heat pumps. A large
- =percentage of the energy escapes in the form of heat out the exhaust
- =pipe in normal operation. This much energy, at least, would not
- =present in a flywheel.
-
- Yes, we know that. That's why we've made generous allowances for the relative
- efficiencies. We've been assuming the IC engine was about 25% efficient while
- the EV was 100% efficient. You *REALLY* should have read more of the thread
- before jumping in to prove that you haven't been following it.
- --------------------------------------------------------------------------------
- Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
-
- Disclaimer: Hey, I understand VAXen and VMS. That's what I get paid for. My
- understanding of astronomy is purely at the amateur level (or below). So
- unless what I'm saying is directly related to VAX/VMS, don't hold me or my
- organization responsible for it. If it IS related to VAX/VMS, you can try to
- hold me responsible for it, but my organization had nothing to do with it.
-