That is, a battery that could supply the nation's electrical needs for a few
days during a blackout.

The author computes it could be done with a sufficiently large, or
sufficiently numerous, lead-acid batteries. The whole shebang would need
only 5 billion tons of lead. The US has 7 million tons of lead reserves,
while the entire world has approximately 80 million tons.

We'd better get busy looking for more. Chinese toys might be a good place to
start...


(Caution: Real maths in use)
http://physics.ucsd.edu/do-the-math/...sized-battery/

"HeyBub" wrote in
m:

That is, a battery that could supply the nation's electrical needs for
a few days during a blackout.

The author computes it could be done with a sufficiently large, or
sufficiently numerous, lead-acid batteries. The whole shebang would
need only 5 billion tons of lead. The US has 7 million tons of lead
reserves, while the entire world has approximately 80 million tons.

We'd better get busy looking for more. Chinese toys might be a good
place to start...


(Caution: Real maths in use)
http://physics.ucsd.edu/do-the-math/...sized-battery/

Somewhere I read that the battle between DC and AC is being revived. DC
should be better at withstanding weather related interruptions, so fewer
(big) power outages at the transmission line and transformer(?) levels.
Don't ask me about the physics ...
I don't think that a branch falling down on an AC line and breaking it is
any different from a DC line, but apparently it would be easier and
cheaper to bury DC lines than AC lines.

--
Best regards
Han
email address is invalid

I think it's an interesting idea. Makes me wonder if there
are some simpler things we can do, in the meantime. Trim
some trees, and bury power lines when possible.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"HeyBub" wrote in message
m...
That is, a battery that could supply the nation's electrical
needs for a few
days during a blackout.

The author computes it could be done with a sufficiently
large, or
sufficiently numerous, lead-acid batteries. The whole
shebang would need
only 5 billion tons of lead. The US has 7 million tons of
lead reserves,
while the entire world has approximately 80 million tons.

We'd better get busy looking for more. Chinese toys might be
a good place to
start...


(Caution: Real maths in use)
http://physics.ucsd.edu/do-the-math/...sized-battery/

HeyBub wrote:

That is, a battery that could supply the nation's electrical needs
for a few days during a blackout.

For one thing, you wouldn't have a single "national" battery.

You would have many regional batteries located in more strategic
locations with access to major grid tie-in points. The north-american
grid system is not wired to be able to handle energy input from a single
location.

The author computes it could be done with a sufficiently large,
or sufficiently numerous, lead-acid batteries.

And it wouldn't use lead-acid batteries. It would use molten sodium
batteries.

It's already been done in Texas as a way to compensate for needing to
upgrade a transmission line to a small town (Presidio). It would have
been more expensive to string a new transmission line capable of
supplying the town with electricity during peak use, so what they are
doing instead is storing power in the battery during non-peak time and
then drawing power from it during peak time.

===========

http://www.smartplanet.com/blog/thin...ore-power/3747

Presidio, Texas, a border town of under 5,000 people in the Rio Grande
Valley, recently had a 4 megawatt battery installed by Electric
Transmission Texas to improve service. It cost $25 million and was
bigger than a house.

The Big Ol’ Battery (BOB) is dwarfed by Fairbanks’ Battery Energy
Storage System (BESS), installed by ABB Group in 2003. BESS can hold a
charge of 26 Megawatts for up to 15 minutes and is used to back up the
local grid.

The two batteries are quite different. BOB uses sodium and sulfur. BESS
is nickel-cadmium.

But what Don Sadoway of MIT has discovered is that if your metal is
molten, it can hold a lot more power in a lot less space. Sadoway says
his battery costs less than lithium, and holds a charge for a longer
period of time. A battery the size of a shipping container would carry 1
megawatt for several hours.

The design is relatively simple. Melted magnesium at the top, melted
antimony at the bottom, and a salt composed of both elements in the
middle. The salt breaks down as the battery is charged, then rebuilds as
electrons are discharged.

Sadoway, who recently turned 60, said his inspiration was the way
aluminum is coaxed from bauxite by being melted using electricity. For
his birthday he’s getting a symposium in his honor this June. Sadoway is
a University of Toronto alumnus. (Go True Blue.)

While the Sadoway battery is impressive, it really illustrates how far
research must travel to make a smart grid a reality.

Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow. Power demand also fluctuates. Better, more
powerful, and cheaper batteries are needed to match supply with demand.

Sadoway’s battery is one small step down a long, long road. It’s an
interesting technique, but it’s probably not our final answer.

Home Guy wrote:
HeyBub wrote:

That is, a battery that could supply the nation's electrical needs
for a few days during a blackout.

For one thing, you wouldn't have a single "national" battery.

You would have many regional batteries located in more strategic
locations with access to major grid tie-in points. The north-american
grid system is not wired to be able to handle energy input from a
single location.

Read the article. The author pointed that out. His "National Battery" was in
the aggregate.


The author computes it could be done with a sufficiently large,
or sufficiently numerous, lead-acid batteries.

And it wouldn't use lead-acid batteries. It would use molten sodium
batteries.

Again, read the article. The author chose lead-acid for his example because:

A. Lead is the cheapest
B. Efficient (85% in a charge cycle)
C. Well-tested technology (over 150 years of use and development)
D. Lead is common
E. Lead-acid batteries are, by far, the most common option in power storage
devices

On 11/18/2011 6:36 AM, Han wrote:
....

Somewhere I read that the battle between DC and AC is being revived. DC
should be better at withstanding weather related interruptions, so fewer
(big) power outages at the transmission line and transformer(?) levels.
Don't ask me about the physics ...
I don't think that a branch falling down on an AC line and breaking it is
any different from a DC line, but apparently it would be easier and
cheaper to bury DC lines than AC lines.

Any weather-related issues are only a side-effect--the underlying reason
for DC over AC for transmission is cutting the AC losses.

It's now a possibility that wasn't practical before the advent of
solid-state electronics that could be made to handle the necessary
voltages/currents.

Manitoba Hydro has been an early implementor...

http://www.hydro.mb.ca/corporate/facilities/transmission_system.shtml
http://www.hydro.mb.ca/corporate/facilities/ts_nelson.shtml

Siemens has been building transmission lines in China and India, last I
knew there were plans on east coast in US w/ PEPCo altho I haven't
followed progress. Anything like offshore wind will rely on them to get
large amounts of power back to shore.

--

On 11/18/2011 6:56 AM, Stormin Mormon wrote:
I think it's an interesting idea. Makes me wonder if there
are some simpler things we can do, in the meantime. Trim
some trees, and bury power lines when possible.

It's only $$$$...and the protesters who raise barriers against
accomplishing anything anymore.

--

On 11/18/2011 4:20 AM, HeyBub wrote:
....

only 5 billion tons of lead. The US has 7 million tons of lead reserves,
while the entire world has approximately 80 million tons.

We'd better get busy looking for more. Chinese toys might be a good place to
start...

Or all that lead paint had to be good for something besides hazardous
landfill material/employment.

--

On Nov 18, 8:15*am, Home Guy wrote:

Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow.

You didn't mention geothermal - that's about as reliable as it gets.

Edison's original concept was that each home or group of homes would
have its own power plant. Primarily that was probably due to the
limitations of DC power, but the concept is still a good one.

R

HeyBub wrote:

And it wouldn't use lead-acid batteries. It would use molten
sodium batteries.

Again, read the article.

Read my article.

Any such large-scale battery would not use lead-acid.

There are two such large-scale batteries in use. One uses NiCad, the
other uses molten sodium.

Here's why we'll never see a "national battery" using lead-acid
technology:

http://oilprice.com/Energy/Energy-Ge...y-Problem.html

There is simply not enough lead in the world to meet the baseline design
goal (power the country for 1 week). Even if this is scaled back to 1
day, it would require about 700 million tons of lead. There are about
80 million tons of lead in known world reserves.

See also:

http://www.renewableenergyworld.com/...-and-stability

On 11/18/2011 8:34 AM, RicodJour wrote:
On Nov 18, 8:15 am, Home wrote:

Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow.

You didn't mention geothermal - that's about as reliable as it gets.
....

Limitations on sources.

--

On Nov 18, 9:34*am, RicodJour wrote:
On Nov 18, 8:15*am, Home Guy wrote:



Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow.

You didn't mention geothermal - that's about as reliable as it gets.

Edison's original concept was that each home or group of homes would
have its own power plant. *Primarily that was probably due to the
limitations of DC power, but the concept is still a good one.

And more on the topic of the OP, what would seem to be more practical
is what some people are already implementing in their homes as part of
a solar and/or wind generator installation; that is, a bank of
batteries sized to tide that individual house over through periods of
low power generation combined with unavailability of power from the
grid. Generally those same people are still tied into the grid
(although some may choose not to) and can sell power back to the grid
when their production exceeds their use, and then vice versa when the
situation is reversed. If everyone had a setup like that, that would
accomplish the same goal without the need for huge honkin' batteries,
inverters, transformers, etc.

nate

I hadn't noticed that. Well, back to the drawing board.
Unless you want to put batteries in everyone's homes?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


wrote in message
...

This is a great exercise in math but virtually all blackouts
are in
the distribution system, not in the generation system. If
you can't
get the power from the generators to the consumer, you can't
get the
power from a battery to the consumer.

On Nov 18, 8:21*am, dpb wrote:
On 11/18/2011 6:36 AM, Han wrote:
...

Somewhere I read that the battle between DC and AC is being revived. *DC
should be better at withstanding weather related interruptions, so fewer
(big) power outages at the transmission line and transformer(?) levels.
Don't ask me about the physics ...
I don't think that a branch falling down on an AC line and breaking it is
any different from a DC line, but apparently it would be easier and
cheaper to bury DC lines than AC lines.

Any weather-related issues are only a side-effect--the underlying reason
for DC over AC for transmission is cutting the AC losses.

It's now a possibility that wasn't practical before the advent of
solid-state electronics that could be made to handle the necessary
voltages/currents.

Manitoba Hydro has been an early implementor...

http://www.hydro.mb.ca/corporate/facilities/transmission_system.shtml
http://www.hydro.mb.ca/corporate/facilities/ts_nelson.shtml

Siemens has been building transmission lines in China and India, last I
knew there were plans on east coast in US w/ PEPCo altho I haven't
followed progress. *Anything like offshore wind will rely on them to get
large amounts of power back to shore.

--

Also, the insulation required for a DC line is whatever the nominal
voltage is, while the insulation on an AC line must be 1.414 times the
nominal voltage. The line losses are similar, but there has to be an
efficient way to transform from one voltage to another at the end
points, that is where semiconductors can now replace the transformer
and its losses.

"HeyBub" wrote in
:

Again, read the article.

Sorry, I haven't read the article. Nevertheless, below ...
The author chose lead-acid for his example
because:

A. Lead is the cheapest
B. Efficient (85% in a charge cycle)
C. Well-tested technology (over 150 years of use and development)
D. Lead is common
E. Lead-acid batteries are, by far, the most common option in power
storage devices

There must be a reason that lithium batteries are most often used for
systems large (cars) and small (laptops, camera batteries). Isn't high
current charge and discharge one of those reasons?


--
Best regards
Han
email address is invalid

On 18 Nov 2011 19:34:01 GMT, Han wrote:

"HeyBub" wrote in
:

Again, read the article.

Sorry, I haven't read the article. Nevertheless, below ...
The author chose lead-acid for his example
because:

A. Lead is the cheapest
B. Efficient (85% in a charge cycle)
C. Well-tested technology (over 150 years of use and development)
D. Lead is common
E. Lead-acid batteries are, by far, the most common option in power
storage devices

There must be a reason that lithium batteries are most often used for
systems large (cars) and small (laptops, camera batteries). Isn't high
current charge and discharge one of those reasons?

Size and weight

" wrote in
news
On 18 Nov 2011 19:34:01 GMT, Han wrote:

"HeyBub" wrote in
:

Again, read the article.

Sorry, I haven't read the article. Nevertheless, below ...
The author chose lead-acid for his example
because:

A. Lead is the cheapest
B. Efficient (85% in a charge cycle)
C. Well-tested technology (over 150 years of use and development)
D. Lead is common
E. Lead-acid batteries are, by far, the most common option in power
storage devices

There must be a reason that lithium batteries are most often used for
systems large (cars) and small (laptops, camera batteries). Isn't high
current charge and discharge one of those reasons?

Size and weight

Of course, Li is quite a bit lighter than Pb ...

--
Best regards
Han
email address is invalid

Don't need batteries -- use a spinning flywheel connected to a
motor/generator for the energy storage. Then all you need is mass. Make
the flywheel out of steel or even concrete or stone. Make lots of them, put
them everywhere and you have a simple, low cost energy storage system with
unlimited capacity.

Tomsic


"Stormin Mormon" wrote in message
...
I hadn't noticed that. Well, back to the drawing board.
Unless you want to put batteries in everyone's homes?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.


wrote in message
...

This is a great exercise in math but virtually all blackouts
are in
the distribution system, not in the generation system. If
you can't
get the power from the generators to the consumer, you can't
get the
power from a battery to the consumer.

wrote in
:

On Fri, 18 Nov 2011 14:56:25 -0500, "Tomsic" wrote:

Don't need batteries -- use a spinning flywheel connected to a
motor/generator for the energy storage. Then all you need is mass.
Make the flywheel out of steel or even concrete or stone. Make lots
of them, put them everywhere and you have a simple, low cost energy
storage system with unlimited capacity.

The traditional storage method is pumped water. You fill up a lake at
the top of the hill and run it through a turbine when you want the
energy back. The advantage is, rainfall gives you free energy.

I believe there are a few of those pumped storage hydroelectric systems
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
The enormous losses during pumping and regeneration seem to make this
very inefficient but apparently the differences between off-peak and peak
rates can make it economical. Not relly useful for individuals or small
coomunities, I'd think.
The flywheel seems practical, but of course the amounts of energy stored
may make the system rather dangerous when (not if) it malfunctions. I've
seen the damage when ultracentrifuges go poof, and that was really very
little mass.

--
Best regards
Han
email address is invalid

On 11/18/2011 12:13 PM, hr(bob) wrote:
....
Also, the insulation required for a DC line is whatever the nominal
voltage is, while the insulation on an AC line must be 1.414 times
the nominal voltage. The line losses are similar, but there has to
be an efficient way to transform from one voltage to another at the
end points, that is where semiconductors can now replace the
transformer and its losses.

High voltage overhead lines aren't insulated anyways, and that's the
only place where DC transmission lines are used (or are likely to be
used in the foreseeable future). There may be a few very special cases
where a HV line will be buried, but that's not the target for what is
going to help much at all on end-user reliability.

The transmission line losses are certainly nothing at all alike between
the two; that's the whole reason for doing it in the first place.

I've not heard of anybody proposing low voltage transmission nor
distribution lines as DC...

The little transformers aren't a big part of the problem; it's the high
voltage rectifiers need to convert _TO_ DC for transmission that were
the hangup until solid-state developed to the point they were possible
that way for modern HV transmission to be practical via DC.

--

On Nov 18, 4:13*pm, Han wrote:
wrote :

On Fri, 18 Nov 2011 14:56:25 -0500, "Tomsic" wrote:

Don't need batteries -- use a spinning flywheel connected to a
motor/generator for the energy storage. *Then all you need is mass.
Make the flywheel out of steel or even concrete or stone. *Make lots
of them, put them everywhere and you have a simple, low cost energy
storage system with unlimited capacity.

The traditional storage method is pumped water. You fill up a lake at
the top of the hill and run it through a turbine when you want the
energy back. The advantage is, rainfall gives you free energy.

I believe there are a few of those pumped storage hydroelectric systems
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
The enormous losses during pumping and regeneration seem to make this
very inefficient but apparently the differences between off-peak and peak
rates can make it economical. *Not relly useful for individuals or small
coomunities, I'd think.
The flywheel seems practical, but of course the amounts of energy stored
may make the system rather dangerous when (not if) it malfunctions. *I've
seen the damage when ultracentrifuges go poof, and that was really very
little mass.

--
Best regards
Han
email address is invalid

I'm thinking sabotage could be pretty ugly, too.

nate

Han wrote:
The flywheel seems practical, but of course the amounts of energy
stored may make the system rather dangerous when (not if) it
malfunctions. I've seen the damage when ultracentrifuges go poof,
and that was really very little mass.

The energy stored in a flywheel depends on: a) Its mass, and b) Its
velocity.

You could replicate the energy stored in a ultracentrifuge with a sixty-ton
flywheel moving at 2 r.p.m.

I recall busses in Switzerland running off of flywheels. When it got to the
end of the line, a worker would run up to the back with a motorized probe
and "re-fuel" the flywheel. Took about five minutes. The bus was then good
to go on its route.

On Fri, 18 Nov 2011 04:20:26 -0600, "HeyBub"
wrote:

That is, a battery that could supply the nation's electrical needs for a few
days during a blackout.

Good idea. We could put it in the northern half of Manitoba, which
isn't used anyhow. We could run the cables when they put in that new
pipeline.


The author computes it could be done with a sufficiently large, or
sufficiently numerous, lead-acid batteries. The whole shebang would need
only 5 billion tons of lead. The US has 7 million tons of lead reserves,
while the entire world has approximately 80 million tons.

We'd better get busy looking for more. Chinese toys might be a good place to
start...


(Caution: Real maths in use)
http://physics.ucsd.edu/do-the-math/...sized-battery/

On Fri, 18 Nov 2011 16:48:46 -0600, "HeyBub" wrote:

Han wrote:
The flywheel seems practical, but of course the amounts of energy
stored may make the system rather dangerous when (not if) it
malfunctions. I've seen the damage when ultracentrifuges go poof,
and that was really very little mass.

The energy stored in a flywheel depends on: a) Its mass, and b) Its
velocity.

Actually, it's (1/2) mass * velocity squared.

You could replicate the energy stored in a ultracentrifuge with a sixty-ton
flywheel moving at 2 r.p.m.

True, but that "squared" term matters.

I recall busses in Switzerland running off of flywheels. When it got to the
end of the line, a worker would run up to the back with a motorized probe
and "re-fuel" the flywheel. Took about five minutes. The bus was then good
to go on its route.

I'd like to see a citation for that.

hr(bob) wrote:
On Nov 18, 8:21 am, dpb wrote:
On 11/18/2011 6:36 AM, Han wrote:
...

Somewhere I read that the battle between DC and AC is being revived. DC
should be better at withstanding weather related interruptions, so fewer
(big) power outages at the transmission line and transformer(?) levels.
Don't ask me about the physics ...
I don't think that a branch falling down on an AC line and breaking it is
any different from a DC line, but apparently it would be easier and
cheaper to bury DC lines than AC lines.
Any weather-related issues are only a side-effect--the underlying reason
for DC over AC for transmission is cutting the AC losses.

It's now a possibility that wasn't practical before the advent of
solid-state electronics that could be made to handle the necessary
voltages/currents.

Manitoba Hydro has been an early implementor...

http://www.hydro.mb.ca/corporate/facilities/transmission_system.shtml
http://www.hydro.mb.ca/corporate/facilities/ts_nelson.shtml

Siemens has been building transmission lines in China and India, last I
knew there were plans on east coast in US w/ PEPCo altho I haven't
followed progress. Anything like offshore wind will rely on them to get
large amounts of power back to shore.

--

Also, the insulation required for a DC line is whatever the nominal
voltage is, while the insulation on an AC line must be 1.414 times the
nominal voltage. The line losses are similar,

Look up "skin effect". Even at 60 Hz., it's much shallower than you'd
expect.

but there has to be an
efficient way to transform from one voltage to another at the end
points, that is where semiconductors can now replace the transformer
and its losses.

wrote in message
...
On Fri, 18 Nov 2011 16:48:46 -0600, "HeyBub"
wrote:

Han wrote:
The flywheel seems practical, but of course the amounts of energy
stored may make the system rather dangerous when (not if) it
malfunctions. I've seen the damage when ultracentrifuges go poof,
and that was really very little mass.

The energy stored in a flywheel depends on: a) Its mass, and b) Its
velocity.

Actually, it's (1/2) mass * velocity squared.

You could replicate the energy stored in a ultracentrifuge with a
sixty-ton
flywheel moving at 2 r.p.m.

True, but that "squared" term matters.

I recall busses in Switzerland running off of flywheels. When it got to
the
end of the line, a worker would run up to the back with a motorized probe
and "re-fuel" the flywheel. Took about five minutes. The bus was then good
to go on its route.

I'd like to see a citation for that.

Good memory. I remembered the Swiss flywheel buses too and that's why I
posted the flywheel idea. The buses were described many years ago -- in
Popular Science Magazine, I think. Google "Flywheel buses"; there are some
references listed.

Tomsic

" wrote in
news
On 18 Nov 2011 19:34:01 GMT, Han wrote:

"HeyBub" wrote in
:

Again, read the article.

Sorry, I haven't read the article. Nevertheless, below ...
The author chose lead-acid for his example
because:

A. Lead is the cheapest
B. Efficient (85% in a charge cycle)
C. Well-tested technology (over 150 years of use and development)
D. Lead is common
E. Lead-acid batteries are, by far, the most common option in power
storage devices

There must be a reason that lithium batteries are most often used for
systems large (cars) and small (laptops, camera batteries). Isn't high
current charge and discharge one of those reasons?

Size and weight


lithium-ion battery packs are used because they have the highest energy
density per pound. that translates to longer range.(for a given weight)

--
Jim Yanik
jyanik
at
localnet
dot com

" wrote:

I recall busses in Switzerland running off of flywheels.

I'd like to see a citation for that.

http://www.accesstoenergy.com/view/a...e/s76a4325.htm

===========
(publication date of the following is unknown)

In the early 1950's, the well known Swiss engineering company Oerlikon
introduced the "Gyrobus," a bus for 35 passengers that ran on electric
power generated by a spinning flywheel, which was itself brought up to
speed at points (?) mile apart by tapping the electric power net. The
Gyrobuses were introduced in 1953 and remained in service (some of them
in the Belgian Congo) for 10 years.

They were pushed out by diesel buses, which were not limited to a route
with electrical tap points, nor forced to wait 1 to 2 minutes at each
such point to recharge. Fuel cost was not a consideration at the time.

But diesel buses use more expensive fuel less efficiently and with more
pollution than the corresponding amount of electric power, and so the
flywheel bus may make a comeback - with a flywheel that can store more
energy per unit volume than two decades ago, and controlled by
semiconductor devices, themselves run by microprocessors.

A four-year, $5 million contract for developing a flywheel bus was
awarded to General Electric last year jointly by the Departments of
Energy and Transportation.

The 1.5-ton flywheel will spin at 10,000 rpm, which gives it sufficient
energy to move the 15-ton vehicle with its load of passengers 3.5 miles
by using its 112 kW generator on the flywheel shaft. When its speed has
dropped to 5,000 rpm, the driver pulls over to a charging point, where
the generator, acting as a motor, will bring the flywheel up to full
speed in 90 secs. When the driver accelerates, current is drawn from the
generator on the flywheel shaft; when he brakes, the traction motor,
acting as a generator, "recharges" the flywheel (accelerates it).

Development of the bus will involve GE's R&D Center at Schenectady,
N.Y., its Transportation Systems Div. in Erie, Pa., and its Aircraft
Group in Cincinnati, Ohio.

This type of bus has all the advantages of an electric trolleybus
without the investment and maintenance of miles of overhead wires. The
advantages over diesel buses are energy saving and reduced pollution.
Compared with battery-driven vehicles, the flywheel buses can be
"recharged" in 90 seconds, rather than many hours, and operated round
the clock. Moreover, there is no need to replace expensive batteries;
the service life of the flywheel bus should be similar to that of
conventional buses.

The heart of the bus, the flywheel, runs in a sealed module containing
low-pressure helium so as to minimize aerodynamic friction; if no
current is drawn from the generator, the flywheel will spin for many
hours.

A stack of steel disks weighing 1.5 tons and spinning at 10,000 rpm (167
revs a second!) is, of course, subjected to centrifugal stresses that
could become dangerous if the disks were merely bolted together. They
will therefore be "inertia-welded" by a comparatively new process in
which a rapidly spinning disk is brought into precisely aligned contact
with a stationary disk and pressed against it. The heat of friction is
so high that the rings of contact melt and the two components fuse.
=============


See also:

Low Cost Flywheel Energy Storage for a Fuel Cell Powered Transit Bus
Hearn, Flynn, Lewis, Thompson, Murphy, Longoria

The University of Texas at Austin – Center for Electromechanics
10100 Burnet Rd. EME 133
Austin, TX 78758

ttp://www.rotordynamics.org/Paper_PDFs/2007%20Low%20cost%20flywheel%20energy%20storage%20 for%20fuel%20cell,%20Hearn.pdf

And more on the topic of the OP, what would seem to be more practical
is what some people are already implementing in their homes as part of
a solar and/or wind generator installation; that is, a bank of
batteries sized to tide that individual house over through periods of
low power generation combined with unavailability of power from the
grid. Generally those same people are still tied into the grid
(although some may choose not to) and can sell power back to the grid
when their production exceeds their use, and then vice versa when the
situation is reversed. If everyone had a setup like that, that would
accomplish the same goal without the need for huge honkin' batteries,
inverters, transformers, etc.
==============

It's sad that many solar inastallations that use "grid tie" inverters CANNOT
operate without the grid.

Mark

"dpb" wrote in message ...
On 11/18/2011 12:13 PM, hr(bob) wrote:
...
Also, the insulation required for a DC line is whatever the nominal
voltage is, while the insulation on an AC line must be 1.414 times
the nominal voltage. The line losses are similar, but there has to
be an efficient way to transform from one voltage to another at the
end points, that is where semiconductors can now replace the
transformer and its losses.

High voltage overhead lines aren't insulated anyways, and that's the only
place where DC transmission lines are used (or are likely to be used in
the foreseeable future). There may be a few very special cases where a HV
line will be buried, but that's not the target for what is going to help
much at all on end-user reliability.

The transmission line losses are certainly nothing at all alike between
the two; that's the whole reason for doing it in the first place.

I've not heard of anybody proposing low voltage transmission nor
distribution lines as DC...

The little transformers aren't a big part of the problem; it's the high
voltage rectifiers need to convert _TO_ DC for transmission that were the
hangup until solid-state developed to the point they were possible that
way for modern HV transmission to be practical via DC.

There's been some talk in the lighting industry about wiring homes with low
voltage dc (12 -24 volts) for lighting since LEDs are basically low-voltage
devices and so the 120 volts ac to 12 volts dc conversion steps(and losses)
could be eliminated in lighting fixtures. The wiring could also be designed
to be "Class 2" according to the National Electrical Code (U.S.), which
reduces the chances of electrical shock and fire. The requirements for
connectors, boxes, etc. are simpler too which makes it less expensive and
more DIY-friendly. Think of wiring and hardware like doorbell, telephone,
car or boat wiring than what we use now for switches, outlets and lighting
fixtures in homes.

There's a global organization called the Zhaga Consortium woking on the
details.

Tomsic

zzzzzzzzzz wrote:

I recall busses in Switzerland running off of flywheels. When it got
to the end of the line, a worker would run up to the back with a
motorized probe and "re-fuel" the flywheel. Took about five minutes.
The bus was then good to go on its route.

I'd like to see a citation for that.

You can cite my post.

" wrote in
:

I'd like to see a citation for that.


http://en.wikipedia.org/wiki/Gyrobus

--
Best regards
Han
email address is invalid

Home Guy wrote:
" wrote:

I recall busses in Switzerland running off of flywheels.
I'd like to see a citation for that.

http://www.accesstoenergy.com/view/a...e/s76a4325.htm

===========
(publication date of the following is unknown)

In the early 1950's, the well known Swiss engineering company Oerlikon
introduced the "Gyrobus," a bus for 35 passengers that ran on electric
power generated by a spinning flywheel, which was itself brought up to
speed at points (?) mile apart by tapping the electric power net. The
Gyrobuses were introduced in 1953 and remained in service (some of them
in the Belgian Congo) for 10 years.

They were pushed out by diesel buses, which were not limited to a route
with electrical tap points, nor forced to wait 1 to 2 minutes at each
such point to recharge. Fuel cost was not a consideration at the time.

But diesel buses use more expensive fuel less efficiently and with more
pollution than the corresponding amount of electric power, and so the
flywheel bus may make a comeback - with a flywheel that can store more
energy per unit volume than two decades ago, and controlled by
semiconductor devices, themselves run by microprocessors.

A four-year, $5 million contract for developing a flywheel bus was
awarded to General Electric last year jointly by the Departments of
Energy and Transportation.

The 1.5-ton flywheel will spin at 10,000 rpm, which gives it sufficient
energy to move the 15-ton vehicle with its load of passengers 3.5 miles
by using its 112 kW generator on the flywheel shaft. When its speed has
dropped to 5,000 rpm, the driver pulls over to a charging point, where
the generator, acting as a motor, will bring the flywheel up to full
speed in 90 secs. When the driver accelerates, current is drawn from the
generator on the flywheel shaft; when he brakes, the traction motor,
acting as a generator, "recharges" the flywheel (accelerates it).

Development of the bus will involve GE's R&D Center at Schenectady,
N.Y., its Transportation Systems Div. in Erie, Pa., and its Aircraft
Group in Cincinnati, Ohio.

This type of bus has all the advantages of an electric trolleybus
without the investment and maintenance of miles of overhead wires. The
advantages over diesel buses are energy saving and reduced pollution.
Compared with battery-driven vehicles, the flywheel buses can be
"recharged" in 90 seconds, rather than many hours, and operated round
the clock. Moreover, there is no need to replace expensive batteries;
the service life of the flywheel bus should be similar to that of
conventional buses.

The heart of the bus, the flywheel, runs in a sealed module containing
low-pressure helium so as to minimize aerodynamic friction; if no
current is drawn from the generator, the flywheel will spin for many
hours.

A stack of steel disks weighing 1.5 tons and spinning at 10,000 rpm (167
revs a second!) is, of course, subjected to centrifugal stresses that
could become dangerous if the disks were merely bolted together. They
will therefore be "inertia-welded" by a comparatively new process in
which a rapidly spinning disk is brought into precisely aligned contact
with a stationary disk and pressed against it. The heat of friction is
so high that the rings of contact melt and the two components fuse.
=============


See also:

Low Cost Flywheel Energy Storage for a Fuel Cell Powered Transit Bus
Hearn, Flynn, Lewis, Thompson, Murphy, Longoria

The University of Texas at Austin – Center for Electromechanics
10100 Burnet Rd. EME 133
Austin, TX 78758

ttp://www.rotordynamics.org/Paper_PDFs/2007%20Low%20cost%20flywheel%20energy%20storage%20 for%20fuel%20cell,%20Hearn.pdf

There are a BUNCH of system issues with flywheel buses that get
"recharged" externally.
3.5miles is inconvenient for many bus lines.
Somebody's gotta get out and plug in the charger...over and over and
over. Some form of automated connection will be required.
Buses tend to congregate at transfer stations. So, the peak load
on the grid can be huge. Maybe the transit station has its own
flywheel...yet another loss in efficiency.
There are issues with mounting a 1.5 ton flywheel that gets jostled
in three dimensions and likes to twist at right angles.
Building a computer model of a flywheel is a lot easier than building
a fleet of buses and the infrastructure to support them.

I know a guy in the engineering department for the local transit system.
Much of the energy cost of a bus is in starting and stopping a huge mass
every three blocks...or every 10 feet in traffic.
He claims their experimental compressed-air regenerative braking system
is saving 30% on fuel costs. Only needs enough storage to stop the bus.
Because it cycles rapidly, there's significant reduction in loss
of heat caused by the compression.

mike unnecessarily full-quoted:

Much of the energy cost of a bus is in starting and stopping a huge
mass every three blocks...or every 10 feet in traffic.

experimental compressed-air regenerative braking system is saving
30% on fuel costs. Only needs enough storage to stop the bus.
Because it cycles rapidly, there's significant reduction in loss
of heat caused by the compression.

I wonder if a simple spring mechanism couldn't be used during breaking,
then use that energy to get the bus moving again.

In article ,
some people who I cannot keep track of wrote:
I recall busses in Switzerland running off of flywheels. When it got to the
end of the line, a worker would run up to the back with a motorized probe
and "re-fuel" the flywheel. Took about five minutes. The bus was then good
to go on its route.

I'd like to see a citation for that.


Google or wikipedia for "gyrobus" The "route" BTW was only about 6 km.

--
When the game is over, the pawn and the king are returned to the same box.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org

On 11/18/2011 7:35 PM, Tomsic wrote:
....

There's been some talk in the lighting industry about wiring homes with low
voltage dc (12 -24 volts) for lighting since LEDs are basically low-voltage
devices and so the 120 volts ac to 12 volts dc conversion steps(and losses)
could be eliminated in lighting fixtures....

That's a completely different part of the picture, however...

--

Home Guy wrote:
mike unnecessarily full-quoted:
unnecessarily snipped...
it IS a spring.
AKA hydraulic accumulator

On 11/18/2011 1:56 PM, Tomsic wrote:
Don't need batteries -- use a spinning flywheel connected to a
motor/generator for the energy storage. Then all you need is mass. Make
the flywheel out of steel or even concrete or stone. Make lots of them, put
them everywhere and you have a simple, low cost energy storage system with
unlimited capacity.

Tomsic


When I was out in the Pacific at a missile range, some of the computer
systems on one island had backup power that utilized flywheels. I never
got a look at them and don't know for how long the motor generator units
were able to provide power to the systems but they had been around for
years. Of course all the primary power was supplied by big EMD diesel
generators at the power house.

TDD

On Nov 18, 1:15*pm, Home Guy wrote:
HeyBub wrote:
That is, a battery that could supply the nation's electrical needs
for a few days during a blackout.

For one thing, you wouldn't have a single "national" battery.

You would have many regional batteries located in more strategic
locations with access to major grid tie-in points. *The north-american
grid system is not wired to be able to handle energy input from a single
location.

The author computes it could be done with a sufficiently large,
or sufficiently numerous, lead-acid batteries.

And it wouldn't use lead-acid batteries. *It would use molten sodium
batteries.

It's already been done in Texas as a way to compensate for needing to
upgrade a transmission line to a small town (Presidio). *It would have
been more expensive to string a new transmission line capable of
supplying the town with electricity during peak use, so what they are
doing instead is storing power in the battery during non-peak time and
then drawing power from it during peak time.

===========

http://www.smartplanet.com/blog/thin...tteries-pack-m...

Presidio, Texas, a border town of under 5,000 people in the Rio Grande
Valley, recently had a 4 megawatt battery installed by Electric
Transmission Texas to improve service. It cost $25 million and was
bigger than a house.

The Big Ol’ Battery (BOB) is dwarfed by Fairbanks’ Battery Energy
Storage System (BESS), installed by ABB Group in 2003. BESS can hold a
charge of 26 Megawatts for up to 15 minutes and is used to back up the
local grid.

The two batteries are quite different. BOB uses sodium and sulfur. BESS
is nickel-cadmium.

But what Don Sadoway of MIT has discovered is that if your metal is
molten, it can hold a lot more power in a lot less space. Sadoway says
his battery costs less than lithium, and holds a charge for a longer
period of time. A battery the size of a shipping container would carry 1
megawatt for several hours.

The design is relatively simple. Melted magnesium at the top, melted
antimony at the bottom, and a salt composed of both elements in the
middle. The salt breaks down as the battery is charged, then rebuilds as
electrons are discharged.

Sadoway, who recently turned 60, said his inspiration was the way
aluminum is coaxed from bauxite by being melted using electricity. For
his birthday he’s getting a symposium in his honor this June. Sadoway is
a University of Toronto alumnus. (Go True Blue.)

While the Sadoway battery is impressive, it really illustrates how far
research must travel to make a smart grid a reality.

Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow. Power demand also fluctuates. Better, more
powerful, and cheaper batteries are needed to match supply with demand.

Sadoway’s battery is one small step down a long, long road. It’s an
interesting technique, but it’s probably not our final answer.

The man is clearly mentally deranged.

On Nov 18, 2:34*pm, RicodJour wrote:
On Nov 18, 8:15*am, Home Guy wrote:



Renewable power is not reliable — clouds obscure the sun, and sometimes
the wind doesn’t blow.

You didn't mention geothermal - that's about as reliable as it gets.

Edison's original concept was that each home or group of homes would
have its own power plant. *Primarily that was probably due to the
limitations of DC power, but the concept is still a good one.

R
Any batteries would only last a few hours. People can manage for a few
hours without electricity so the whole exercise is pointless.