HDTenEightyP/NetNews huggingface dataset:
From: howard.smith@spacebbs.com (Howard Smith) 
Newsgroups: sci.energy
Subject: Re: Wind Energy Weekly
Date: 5 Jan 93 13:20:00 GMT
Distribution: world
Organization: SPACE BBS - Menlo Park, CA - 10 Lines + 4gB - 415-323-4193
Reply-To: howard.smith@spacebbs.com (Howard Smith) 

RS>> Worldwide wind generation will likely reach 4.3 billion kWh in
RS>> 1992. California, which due to poor winds is not expected to
RS>> produce more than the 2.7 billion kWh recorded last year, will
RS>> account for about 67% of total world production.

RS>Shows the sorry state of world-wide wind development, since the world total
RS>does not approach the output of a single nuke over 1 year.

Yes, but it is now growing at a high rate after years in the doldrums.
The new $0.05/KWhr 300KW+ machines will expedite installations further.
Three cent machines are just a couple of years away. Probably closer
than your type accepted, packaged nuke plants.

hhs
---
 . SLMR 2.1a . 
                                                                                     
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SPACE BBS - Menlo Park, CA - 10 Lines - BoardWatch Top Ten BBS
415-323-4193 (v.32bis) - 4gB (50,000 files) + Wx, UPI News, etc.
Newsgroups: sci.energy
From: weimer@spud.NoSubdomain.NoDomain (Gary Weimer 726-3370)
Subject: Re: Flywheel batteries---reality check
Reply-To: weimer@pixel.kodak.com
Organization: Eastman Kodak Co.; Rochester, NY
Date: Fri, 8 Jan 93 17:13:05 GMT

|> > In article <51775@seismo.CSS.GOV> stead@skadi.CSS.GOV (Richard Stead) writes:
|> > >Oh, well that is a little fast (rim velocity of 3060 kph) - maybe the
|> > >tunnel could be under a little vacuum so that velocity is below sound
|> > >speed.

Does it matter that we exceed the speed of sound if we are not
displacing any air? It sounds like you're talking about spinning a solid
rim with no spokes. This would cause friction with the surounding air,
but does it create a shock wave?

-- 

Gary Weimer (weimer@pixel.kodak.com)
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.energy
Subject: Re: Flywheel batteries---reality check
Date: 10 Jan 93 16:37:03 GMT

In article <6193@gumby.Altos.COM>, robk@gumby.Altos.COM (Rob Kleinschmidt) writes:
> In article <51769@seismo.CSS.GOV> stead@skadi.CSS.GOV (Richard Stead) writes:
> 
> >               Therefore, in shredding a flywheel to "fluff" you have only
> >broken a minute percentage of its bonds.  Since the computations show that
> >the total energy stored in the most efficient, lowest stress flywheel
> >design must be less than half the total bond energy - any higher energy
> >densities will simply cause the atoms to fly apart.
> 
> I seem to recall that in earlier flywheel experiments, the failure
> occurred first in the resin bonding material, rather than in the
> fibers, and that the fibers might actually be intact but unglued
> after the failure. Would this not be true with materials used in
> the present design ? If true, how might this affect your failure
> analysis ?
> 
> My vague memory is that the fiber was described as pehaps unwound
> in the containment chamber with all resin bonds separated. Seems
> as though winding techniques would strongly influence failure modes,
> and that it is unlikely the whole thing would disintegrate instantly.
> Instead of killer fluff, perhaps we have the weedwhacker from hell ??

First, if the flywheel is resin-bound, the resin will be far weaker than
the carbon fiber.  It will become the limiting strength of the flywheel,
and thus the flywheel will have even lower maximum energy densities.  But
the important thing to note is where the maximum stress is.  The maximum
stress is the hoop stress - the stress tangential to the rotor.  In the
flywheel design, the fibers were spoolled in the rotor, such that this
maximum stress is directly resisted by continuous, strong fibers.  Any
binding material will simply add weight to this rotor and counteract the
smaller radial stress.  The resin will be ineffective in resisting failure,
since failure will necessarily involve forces large enough that only
the carbon fiber can resist.  In addition, any failure introduces
disequilibrium in the flywheel.  The flywheel will then take on the order of
its rim velocity to contact the containment walls, inducing massive failure
at that point, if it hasn't already begun to disintegrate.  Given the
high rim velocity.  From this, it is apparent that the rotor will fail
in microseconds, if not as fluff, then as shrapnel.  Also, since the
fibers are under such high tension, and their sound speed is so low,
failure will induce a shock wave in the material.  This shock wave should
be able to traverse the material before the rotor can interact with
containment, heating and possibly disintegrating the material as it goes.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: hoyt@isus.UUCP (Hoyt A. Stearns jr.)
Subject: Re: Electric airplanes ...(high P/W electric motors & fuel cells)
Followup-To: sci.energy
Summary: High P/W motors
Keywords: electric rare-earth motors
Organization: International Society of Unified Science
Date: Thu, 7 Jan 1993 04:04:24 GMT

In article <C0Eoqy.Dsy.1@cs.cmu.edu> dep+@CS.CMU.EDU (David Pugh) writes:
>I'm interested in replacing the engine in a small GA plane with an electric
>motor and fuel cells. I've seen several articles in the lay press over the
>past few years that indicate that this should be feasible. Unfortunately, those
>articles were very short on details.
>
I've been working on an electric helicopter for some time.
It will have 75HP samarium cobalt motors mounted inside the blades,
driving cross-flow fans at the tips.

The motors are 1 meter long and 3cm diameter, and yield 8HP/pound-mass.
These are synchronous 3-phase permanent magnet motors, and are very
efficient.

Several companies can make them: Versatron, Healdsburg CA, (707 433
8244) and Gould are two. I recall Gould made 200 HP motors for a blimp.
Versatron makes a 50 HP beer-can sized motor.

I think fuel cells are still a bit heavy (800 pounds for 150 KW),
but that will surely improve, meanwhile you can use an engine
driving an alternator of the same technology as the motors.

The high power to weight ratio motors spin in the 200,000 RPM range.
To drive a prop, you might look at a harmonic drive reducer..

Semiconductor technology can easily handle hundreds of kilowatts now
with 50A 1000V mos controlled thyristors and other types of power 
devices.

You even have the option of a minute or so of full power from a
battery in case of fuel exhaustion.

-- 
Hoyt A. Stearns jr.|hoyt@          | International Society of Unified Science|
4131 E. Cannon Dr. |isus.tnet.com -| Advancing Dewey B. Larson's Reciprocal  |
Phoenix, AZ. 85028 |ncar!enuucp!   | System- a unified physical theory.      |
voice_602_996_1717 telesys!isus!hoyt The Universe in two postulates__________|
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.energy
Subject: Re: Flywheel batteries---reality check
Date: 4 Jan 93 14:09:13 GMT

In article <1993Jan4.062953.19498@math.ucla.edu>, barry@arnold.math.ucla.edu (Barry Merriman) writes:
> Arguments aside, the latest Popular Science had an article
> on a start-up company that has designed what they contend to be a 
> workable flywheel battery.

You say "reality check" - but that is exactly what this thread has attempted
to provide.  Popular Science does not have a very good reputation for
checking into the validity of the claims they report.  I and others in this
thread have shown that the flywheel design proposed (and we have specifically
addressed this Popular Science article several times) can not possibly
be realistic.  What we have shown is that this "company" is just another
example of the type of "free-energy" conmen so common these days.  They
have some pretty computer pictures they show to "investors" to get their
cash, and it's gotta be real - it's on the computer, right?  For a reality
check, review the computations in this thread - especially those regarding
minimum material strength and how it relates to maximum enrgy storage, and
why "fluff" is hazardous at the energy levels which must be present.

> It is made of a Kevlar strap(=> high strength, low cost) rolled up like 

The material strength computations that refute the design assumed ultimate
strength carbon fiber - stronger than kevlar.

> a roll of toilet paper. Each flywheel occupies a box about the 
> size of a conventional battery, and they claim 12 (set counter rotating
> to negate the angular momentum) will give up to 

Atomic bond strength considerations alone require larger mass than this
indicates, and no material achieves strength equivalent to theoretical
total bond strength.

> a 600 mile range, as well as good acceleration. As for safety, 
> they contend that the failure mode of the kevlar belt results in
> something like cotton candy, so the energy is very disbursed---no
> shrapnel as with metal flywheels. Also, having the energy distributed

Doesn't matter how disbursed, energy is conserved - read the thread in detail.

They will get "cotton candy" in their flywheels, and the flywheels will not
explode; but only because they will never get anywhere near the energy
densities required to power a car 600 miles.  At less than 100th the energy
they need, the flywheel will fail.  Of course, these are conmen - they will
never build the prototype - they will always be asking "investors" for more
money, claiming the prototype is just around the corner.  Feel free to throw
your money away on this project - hopefully the discussion of the past
few weeks has helped others avoid this scheme.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
Newsgroups: sci.energy
From: kk881595@longs.LANCE.ColoState.Edu (kevin knappmiller)
Subject: Re: Flywheel as Mountain Bike energy storage medium
Date: Fri, 08 Jan 1993 21:17:15 GMT
Reply-To: kk881595@longs.LANCE.ColoState.Edu
Organization: Colorado State U. Engineering College

In article <1993Jan7.232707.17753@math.ucla.edu>, barry@arnold.math.ucla.edu (Barry Merriman) writes:
|> The viscocity of air is _higher_ than that of water. 

How _high_ are you?  Or is viscocity not viscosity? ;-)

The dynamic viscosity of water is about 60 times higher than that
of air.  Water is also about 1000 times denser so the kinematic
viscosity of water is about 16 times higher than that of water
so that is probably what you were talking about, 
but when you just say "viscosity" you haven't just said it all, 
most people think of dynamic viscosity when they read "viscosity".

ie nu=mu/rho

Depending on how you are modelling things each of these
quantities might be important or not.  When you are taking about
the propensity a fluid has to flow through a very small hole
the surface tension is probably more important than either
of these.

Kevin Knappmiller
Solar Lab
Colorado State University
Fort Collins
kk881595@longs.lance.colostate.edu
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.energy
Subject: Re: Flywheel batteries---reality check
Date: 6 Jan 93 19:55:29 GMT

In article <1993Jan6.160055.16415@cs.rochester.edu>, dietz@cs.rochester.edu (Paul Dietz) writes:
> Such an externally confined flywheel is not terribly interesting for
> vehicles, but it might be of interest for stationary power storage.
> This is because high strength materials are expensive.  You'd rather
> carry the load in bedrock instead of kevlar.

Excellent idea.  (And I had only thought of bedrock for containment in the
event of failure).  How would you propose to execute the confinement?
Obviously, big roller bearings would work, but the friction losses would be
too large, and vibration from moving over the rollers at high speed would
probably fracture the rotor.  Could this be done magnetically?  How does
one push against the outer diameter of a ring in all directions using
a magnet?  This would lead to something else interesting - at really
high energy densities (the rotor would be under considerable compression,
possibly 100's of kbar), a failure would result in an implosion.  Possibly
something very much like a rockburst in a deep mine.  No big deal though,
just pour some concrete in to replace the blown out bedrock, drop in a
new rotor and you're ready to go.  I like this, it could work for short
term power storage.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
From: stead@skadi.CSS.GOV (Richard Stead)
Newsgroups: sci.energy
Subject: Re: Nuclear Power and Cli
Date: 5 Jan 93 16:22:07 GMT

In article <1993Jan4.220713.8624@vexcel.com>, dean@vexcel.com (Dean Alaska) writes:
> In article <51738@seismo.CSS.GOV> stead@skadi.CSS.GOV (Richard Stead) writes:
> >
> >Depends on your definition of harvestable.  How about a reference describing
> >this for us?  Does it include giving plenty of clearance for roadways,
> >right-of-ways, towns and residences?  How about sensitive habitat, were
> >wetlands, forests, riparian environments, etc. eliminated from consideration?
> >How about conflict between agricultural uses and the wind farms?
> 
> All of these factors have been taken into consideration.  Wind farms

I'll take your word on that.

> work well in conjunction with agricultural land.  Storage and

I'm still a bit hesitant here - it should work well on large ranches
raising animals (as long as it didn't stress the animals too much),
but raising crops in somewhat arid regions (most of the high plains)
requires irrigation.  In the high plains, this is typically done with
above-ground apparatus that moves around and sprinkles the ground.  There
are various types, but they are all very long and must be able to sweep
across acres of land unimpeded.  The wind turbines could then only be
at the perimeters of the fields.

> long distance transmission are the problems to wind energy becoming

That is a big problem, but probably not the biggest.  Centrally collect
a whole bunch of wind power on a grid, then run it along a high-voltage
DC line.  The losses are less, and you can probably go 1500 miles reasonably
with such technology.  It isn't necessarily cheap, however.

> Based on previous discussions, it would seem that
> flywheels might be a good form of storage sometime soon. 

No, the forgoing discussion showed flywheels are not a good technology
for this.  Flywheels are good in stationary applications (using very large
wheels) for either 1) short-term very high power needs or 2) very short
uninterruptible power.  The best storage technology for power engineering
is pumped storage.  Water is pumped into an elevated reservoir, then run
back through turbines when power is needed.  This is very useful for
avoiding brownouts, but I don't know how it would work for baseload.


--
Richard Stead
Center for Seismic Studies
Arlington, VA
stead@seismo.css.gov
Newsgroups: sci.energy
From: steinly@topaz.ucsc.edu (Steinn Sigurdsson)
Newsgroups: sci.energy
Subject: Re: Nuclear Power and Climate Change
Date: 11 Jan 93 12:07:16
Organization: Lick Observatory/UCO
	<louis.726169597@aupair.cs.athabascau.ca>
NNTP-Posting-Host: topaz.ucsc.edu
In-reply-to: louis@aupair.cs.athabascau.ca's message of 4 Jan 93 17:46:37 GMT

In article <louis.726169597@aupair.cs.athabascau.ca> louis@aupair.cs.athabascau.ca (Louis Schmittroth) writes:

   >To claim a capital cost of $1000/kw is extremely optimistic...perhaps
   >even fanciful. In today's dollars foir an LWR or a CANDU (excluding 
   >heavy water) a capital cost of $2000/kw may be fair.

   I have no experience in costing nuclear power plants of any kind, but
   I did read the article in The Economist for Nove 21-27 '92, entitled
   Nuclear Power -- Losing ist charm.  On page 22 there is a little table
   of capital costs of US nuclear power plants by year of construction
   start, 1982 dollars per kW.  There you will find that for the 5 plants
   started in 1976,77, the estimated cost at start of construction was
   $794, at half-way, $1065, and at completion, $2132.

   So, that should put the discussion of $250/kW or even $1200/kW to rest,
   no?  Unless of course The Economist is to be dismissed as a pinko,
   liberal, econazi rag?

No, but how much of the cost increase was due to interest costs
on capital while operating permits were delayed by legal action and
design reviews - as opposed to actual construction cost?
I've been involved in determining costs of hydro power stations,
and _the_ uncertainty in deciding whether to go ahead with
construction is whether nuclear power stations will become cheap
enough to undercut the hydro - with essentially all the uncertainty
attributed to delays rather than materials or labour.

   The article is very pessimistic for any increase in installed capacity
   except a small increase in France, Japan, and Canada, and even there
   the economics are only slightly better than fossil fuel plants.

Japan's latest goal was to more than double their nuclear capacity
in about 30 years (to go from 23% or so to 47% - with the higher
percentage at higher total capacity, so actual nuclear capacity more
than doubles).

|  Steinn Sigurdsson	|For people are different           		|
|  Lick Observatory	|And so are nations                            	|
| steinly@lick.ucsc.edu |You can borrow ideas                   	|
| "standard disclaimer"	|But you can't borrow situations   - B.B. 1991	|
From: howard.smith@spacebbs.com (Howard Smith)
Newsgroups: sci.energy
Subject: ***Wind Energy Weekly #516***
Date: 4 Jan 93 08:54:00 GMT
Reply-To: howard.smith@spacebbs.com (Howard Smith)
Organization: SPACE BBS - Menlo Park, CA - 10 Lines + 4gB - 415-323-4193

Reply-To: Conference "en.energy" <en.energy@conf.igc.apc.org>
From: Tom Gray <tgray@igc.apc.org>
Date: 04 Jan 93 07:53 PST
To: Recipients of conference "en.energy" <en.energy@conf.igc.apc.org>


The following topics contain news items from Wind Energy Weekly,
Vol. 11, #516, 9.28.92, published by the American Wind Energy
Association.  For more information on the Association, contact
AWEA, 777 North Capitol, NE, Suite 805, Washington, DC 20002, USA,
phone (202) 408-8988, fax (202) 408-8536, telex 6503304640 MCI UW.

Hit <CR> to see the first item.
---
 . SLMR 2.1a . 
                             
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SPACE BBS - Menlo Park, CA - 10 Lines - BoardWatch Top Ten BBS
415-323-4193 (v.32bis) - 4gB (50,000 files) + Wx, UPI News, etc.
From: hardie@herald.usask.ca (Peter Hardie)
Newsgroups: sci.energy
Subject: Re: Nuclear Power and Climate Changes
Date: 7 Jan 1993 22:36:43 GMT
Organization: University of Saskatchewan
Distribution: world
NNTP-Posting-Host: herald.usask.ca
Originator: hardie@herald.usask.ca

+== and + are from wcarroll@encore.com (William Carroll):
+= hardie@herald.usask.ca (Peter Hardie,4805)

+== Well, since the emergency systems are part of the nuke plant, and required
+== for its operation, I would say that, yes, the nuclear plant was damaged. No,
+== the containment buildings were not damaged. Or at least not to a newsworthy
+== level.
+
+=You do love to contradict yourself, don't you?
+
+How is the above contradictiory? There is a lot more to a nuclear plant than
+the containment building.

AH! but that is where you have totally strayed from the origin of this whole
thread and missed my point. Richard Stead wrote:
  "No comparison.  Containment structures are designed to withstand the
   strongest tornadoes - a mere typhoon would simply give the plant a nice
   bath. Just look at some of the stuff our last big hurricane did in
   Florida.  That's exactly what a typhoon does."

His subject is clearly, and only, the structural integrity of the
containment buildings. And, to this, you posted:

  "You mean, like knocking the Turkey Point nuclear plant offline for
   several weeks? That's one hell of a bath!"

Which clearly implies, whether you like it or not, that the containment
buildings were damaged sufficiently to "knock" the plant offline.

In your last posting you admitted that the containment buildings were
not damaged, but then you qualified that by saying:
  "Or at least not to a newsworthy level"
which implies that you do believe that there was damage, otherwise there's
no point to this last statement. So you extrapolated damage to the
containment buildings from the fact that there were no reports of damage to
those buildings?

and it continued:
+="a newsworthy level" indeed!!! Describe the precise DAMAGE to the
+=containment buildings.
+
+Having never been onsite at the Turkey Point plant, I could neither describe
+firsthand the condition of the plant before or after the storm. Can you?
+Remember, be precise!

As you wish. I have never been to Florida and, furthermore, I have
absolutely no information whatever to indicate that any of the
containment buildings at Turkey Point nuclear plant was damaged by the
hurricane and nor do you.

Now it's your turn. In the context of a discussion on the structural
integrity of the containment buildings (which, as I have shown, is the
starting point here), and given that you admit you have no idea of the
plant's condition before or after the storm, explain how the storm "knocked"
the plant offline.

Remember two things.
1. The sirens aren't part of the containment structure.
2. Be precise.

Have a nice day.
Pete Hardie@herald.usask.ca
Newsgroups: sci.energy
From: mancus@carla.jsc.nasa.gov (Keith Mancus/MDSSC)
Subject: Re: Flywheel batteries---reality check
Organization: nasa-jsc
Date: Thu, 7 Jan 1993 15:11:20 GMT

In article <51775@seismo.CSS.GOV> stead@skadi.CSS.GOV (Richard Stead) writes:
>In article <1993Jan6.204853.25975@cs.rochester.edu>, dietz@cs.rochester.edu (Paul Dietz) writes:

>Oh, well that is a little fast (rim velocity of 3060 kph) - maybe the
>tunnel could be under a little vacuum so that velocity is below sound
>speed.

  What good will that do?  The speed of sound in air is proportional
to its temperature, not its pressure.  Or did you mean that you would
pump it down to a hard enough vacuum that the shock waves would
cease to be significant?

-- 
| Keith Mancus    <mancus@cheers.jsc.nasa.gov>                           |
|                 N5WVR                                                  |
| "Money is never *mere*.  It separates the feasible                     |
|    from the infeasible."                                               |
Xref: sparky sci.energy:6638 misc.consumers.house:16297
From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: sci.energy,misc.consumers.house
Subject: Re: Domestic Water Heaters - oil vs. electric
Date: 5 Jan 93 15:54:50 GMT
Followup-To: sci.energy
Organization: Elegant Communications Inc., Ottawa, Canada

In article <1993Jan2.055232.5497@adobe.com> pngai@adobe.com (Phil Ngai) writes:
>In article <1hvil4INNbje@morrow.stanford.edu> ho@sumex-aim.Stanford.EDU (Hiang-Kwee Ho) writes:
>>However, in theory (and in practice in some cases), a much more efficient way 
>>of heating is to use a heat pump. Since a heat pump produces typically
>>3-7 times the amount of heat for a given input of work (or electricity), its
>>performance beats the performance of any oil or electric water heater by
>>a wide margin. (The actual "efficiency" or coefficient of performance of the 
>>heat pump depends on the initial temperature of the cold water, the desired
>>hot water temperature etc.)

>For making hot water at useful temperatures during the winter, I believe
>that heat pumps are unsuitable. What is the max delta T you can achieve
>at a profitable efficiency with a heat pump?

During reasonable seasons for a heat pump, a heat pump will get room air
up to about 115F with a forced air system.  So, with most air source heat
pumps, you could almost get reasonably hot water during the times that the
outside temperature were a few degrees or more above freezing.  However,
recovery time would probably be quite slow.  And in areas such as mine, it
would be useless during the winter.

It might be useful to use a heat pump system as pre-heat for a more
conventional water heater, but not as primary.  In warmer climes.  Where
you've already got a heat pump for house heat.  It'd probably be cheaper
to go solar for pre-heat - no expensive compressors to burn out.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
Psroff 3.0 info: psroff-request@ferret.ocunix.on.ca
Ferret list: ferret-request@ferret.ocunix.on.ca