Fast Charging... (Flywheel?)

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Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
https://www.greencarreports.com/news/1115199_what-electric-car-charging-will-satisfy-a-mass-market-twitter-poll-results

I wonder how big a flywheel is needed to store the energy to charge a 250
mile range in 20 minutes?
Since it is fixed, and does not have to be in a vehicle, it might be the
answer to large charging stations.

When ten TESLAs pull up at ten fast charge cords at the same time, that is
over a megawatt of needed power... in 20 minutes...

Bob
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Re: Fast Charging... (Flywheel?)

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Interesting thought. It might be a good alternative.

But I'm thinking that a large battery (e.g. 100kWh) is cheaper, or at
least will be soon. I don't think one needs larger storage than the
largest battery needing a charge. The advantage of an on-site battery or
flywheel, as I think you imply, is to allow a very rapid charge without
putting an excessive load on the power service.

What will happen, though, if a service station has 10 or 15 ESVEs, which
I think would be realistic along freeways. During times of high
occupancy, the overall load will be more uniform. Someone will start
charging, someone will stop. Meanwhile, 10 other cars will be drawing
full power. So, the starts and stops become less significant. In fact, I
suspect a little math would show a battery roughly equal to the capacity
of one car is sufficient regardless of the number of ESVEs.

Anyway, it comes down to which costs less. Again, I'm pretty sure
battery technology will usurp anything mechanical.

Peri

------ Original Message ------
From: "Robert Bruninga via EV" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Cc: "Robert Bruninga" <[hidden email]>
Sent: 07-Feb-18 2:30:23 PM
Subject: [EVDL] Fast Charging... (Flywheel?)

>https://www.greencarreports.com/news/1115199_what-electric-car-charging-will-satisfy-a-mass-market-twitter-poll-results
>
>I wonder how big a flywheel is needed to store the energy to charge a
>250
>mile range in 20 minutes?
>Since it is fixed, and does not have to be in a vehicle, it might be
>the
>answer to large charging stations.
>
>When ten TESLAs pull up at ten fast charge cords at the same time, that
>is
>over a megawatt of needed power... in 20 minutes...
>
>Bob
>_______________________________________________
>UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>http://lists.evdl.org/listinfo.cgi/ev-evdl.org
>Please discuss EV drag racing at NEDRA
>(http://groups.yahoo.com/group/NEDRA)
>

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Re: Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
In reply to this post by Electric Vehicle Discussion List mailing list
Caltech has a smart EV charging garage that controls 70 EVSE's, granted only
level II -
http://www.caltech.edu/news/smart-charging-network-evs-installed-caltech-50567

link to data
http://ev.caltech.edu/

Rush Dougherty
Tucson AZ 85719


> -----Original Message-----
> From: EV [mailto:[hidden email]] On Behalf Of Peri Hartman via EV
> Sent: Wednesday, February 07, 2018 4:43 PM
> To: Electric Vehicle Discussion List
> Cc: Peri Hartman
> Subject: Re: [EVDL] Fast Charging... (Flywheel?)
>
> Interesting thought. It might be a good alternative.
>
> But I'm thinking that a large battery (e.g. 100kWh) is cheaper, or at least
will be soon. I don't
> think one needs larger storage than the largest battery needing a charge. The
advantage of
> an on-site battery or flywheel, as I think you imply, is to allow a very rapid
charge without
> putting an excessive load on the power service.
>
> What will happen, though, if a service station has 10 or 15 ESVEs, which I
think would be
> realistic along freeways. During times of high occupancy, the overall load
will be more
> uniform. Someone will start charging, someone will stop. Meanwhile, 10 other
cars will be
> drawing full power. So, the starts and stops become less significant. In fact,
I suspect a little
> math would show a battery roughly equal to the capacity of one car is
sufficient regardless of
> the number of ESVEs.
>
> Anyway, it comes down to which costs less. Again, I'm pretty sure battery
technology will

> usurp anything mechanical.
>
> Peri
>
> ------ Original Message ------
> From: "Robert Bruninga via EV" <[hidden email]>
> To: "Electric Vehicle Discussion List" <[hidden email]>
> Cc: "Robert Bruninga" <[hidden email]>
> Sent: 07-Feb-18 2:30:23 PM
> Subject: [EVDL] Fast Charging... (Flywheel?)
>
> >https://www.greencarreports.com/news/1115199_what-electric-car-charging
> >-will-satisfy-a-mass-market-twitter-poll-results
> >
> >I wonder how big a flywheel is needed to store the energy to charge a
> >250
> >mile range in 20 minutes?
> >Since it is fixed, and does not have to be in a vehicle, it might be
> >the answer to large charging stations.
> >
> >When ten TESLAs pull up at ten fast charge cords at the same time, that
> >is over a megawatt of needed power... in 20 minutes...
> >
> >Bob
> >_______________________________________________
> >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> >Please discuss EV drag racing at NEDRA
> >(http://groups.yahoo.com/group/NEDRA)
> >
>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>
>
> ---
> This email has been checked for viruses by AVG.
> http://www.avg.com


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Re: Fast Charging... (Flywheel?)

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In reply to this post by Electric Vehicle Discussion List mailing list
On Wed, Feb 7, 2018 at 2:30 PM, Robert Bruninga via EV
<[hidden email]> wrote:
> I wonder how big a flywheel is needed to store the energy to charge a 250
> mile range in 20 minutes?
> Since it is fixed, and does not have to be in a vehicle, it might be the
> answer to large charging stations.
>
> When ten TESLAs pull up at ten fast charge cords at the same time, that is
> over a megawatt of needed power... in 20 minutes...

That application doesn't capitalize on the flywheel's ultrafast
charging and discharging abilities.
And smoothing can be done by modulating the teslas' charging rates.

But hey, who knows.  See
https://scholar.google.com/scholar?as_ylo=2014&q=flywheel&hl=de&as_sdt=2005&sciodt=0,5&cites=16378509166563059026&scipsc=1
for recent related papers.
- Dan
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Re: Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
As I recall, there was a company that had produced a commercial 30kWh
flywheel storage system. Ideal for peak load shaving,
voltage/frequency stabilisation, and buying off peak to use during the
day etc. Cycle life was essentially infinite with the rotor spinning
on magnetic bearings in an evacuated chamber.

It wasn't physically small, something like 4 meters tall.

JET, the joint European torus fusion research facility uses flywheel
storage to provide the enormous peak power needed to drive the
magnetic bottle.

"The main source of power for establishing the magnetic fields
required for inducing and confining the plasma current in the machine
consists of the two identical Flywheel-Generator-Convertor (FGC)
systems.

At the heart of each system is a 409.8 MVA fly-wheel ALSTOM generator,
with its own auxiliaries including oil systems, air-cooling system,
pony motor, excitation equipment, LV distribution for supply of
auxiliaries and HV distribution for generator excitation and pony
motor drive."

On 8 February 2018 at 16:20, Dan Kegel via EV <[hidden email]> wrote:

> On Wed, Feb 7, 2018 at 2:30 PM, Robert Bruninga via EV
> <[hidden email]> wrote:
>> I wonder how big a flywheel is needed to store the energy to charge a 250
>> mile range in 20 minutes?
>> Since it is fixed, and does not have to be in a vehicle, it might be the
>> answer to large charging stations.
>>
>> When ten TESLAs pull up at ten fast charge cords at the same time, that is
>> over a megawatt of needed power... in 20 minutes...
>
> That application doesn't capitalize on the flywheel's ultrafast
> charging and discharging abilities.
> And smoothing can be done by modulating the teslas' charging rates.
>
> But hey, who knows.  See
> https://scholar.google.com/scholar?as_ylo=2014&q=flywheel&hl=de&as_sdt=2005&sciodt=0,5&cites=16378509166563059026&scipsc=1
> for recent related papers.
> - Dan
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>



--
Paul Compton
www.morini-mania.co.uk
www.paulcompton.co.uk (YouTube channel)
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Re: Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
There are a few technical problems with flywheel energy storage and moving vehicles.There is a term called "precession"It's why a gyroscope stands up when spinning and doesn't fall over. If you push it over it resists and pushes back.If you force it over it goes in a different direction. It "wants" to point in 1 direction.Put a 70,000 revolution per minute gyroscope in a car. You can drive in a straight line only. If you try to turn, you cannot because you have 25+ kilowatts saying otherwise.The car will "precess" around the gyroscope (ie roll over slowly or violently)Then the gyroscope will slip off its bearings and catastrophic disassembleThe new term is RUDWe had an ultracentrifuge spinning 70,000 rpm, it was a pyramidal shaped cylinder that exploded.It "slamdanced" for about 20 minutes it's container , about the size of a refrigerator, hitting walls, bleeding off energy.I think gyroscopes may be good for stationary storage, although Beacon energy, that was pushing it also had an explosion of its energy storage.You also have to continually recertification the centrifuges and take out of use as they still have limited life spans, not good for cars

Sent from Yahoo Mail on Android
 
  On Fri, Feb 9, 2018 at 3:17 AM, Paul Compton via EV<[hidden email]> wrote:   As I recall, there was a company that had produced a commercial 30kWh
flywheel storage system. Ideal for peak load shaving,
voltage/frequency stabilisation, and buying off peak to use during the
day etc. Cycle life was essentially infinite with the rotor spinning
on magnetic bearings in an evacuated chamber.

It wasn't physically small, something like 4 meters tall.

JET, the joint European torus fusion research facility uses flywheel
storage to provide the enormous peak power needed to drive the
magnetic bottle.

"The main source of power for establishing the magnetic fields
required for inducing and confining the plasma current in the machine
consists of the two identical Flywheel-Generator-Convertor (FGC)
systems.

At the heart of each system is a 409.8 MVA fly-wheel ALSTOM generator,
with its own auxiliaries including oil systems, air-cooling system,
pony motor, excitation equipment, LV distribution for supply of
auxiliaries and HV distribution for generator excitation and pony
motor drive."

On 8 February 2018 at 16:20, Dan Kegel via EV <[hidden email]> wrote:

> On Wed, Feb 7, 2018 at 2:30 PM, Robert Bruninga via EV
> <[hidden email]> wrote:
>> I wonder how big a flywheel is needed to store the energy to charge a 250
>> mile range in 20 minutes?
>> Since it is fixed, and does not have to be in a vehicle, it might be the
>> answer to large charging stations.
>>
>> When ten TESLAs pull up at ten fast charge cords at the same time, that is
>> over a megawatt of needed power... in 20 minutes...
>
> That application doesn't capitalize on the flywheel's ultrafast
> charging and discharging abilities.
> And smoothing can be done by modulating the teslas' charging rates.
>
> But hey, who knows.  See
> https://scholar.google.com/scholar?as_ylo=2014&q=flywheel&hl=de&as_sdt=2005&sciodt=0,5&cites=16378509166563059026&scipsc=1
> for recent related papers.
> - Dan
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
>



--
Paul Compton
www.morini-mania.co.uk
www.paulcompton.co.uk (YouTube channel)
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Re: Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
robert winfield via EV wrote:
> There are a few technical problems with flywheel energy storage and moving vehicles...

Robert is right. A flywheel in a vehicle has to be gimballed (like a
gyroscope) so it can remain upright no matter how the car moves. Its
bearing also have to be strong enough to handle bumps and potholes.
That's an additional complication, as the flywheel is by definition heavy.

Flywheels also have the problem of being able to dump *all* of their
stored energy in a moment (KABOOM!) if something goes wrong. Extreme
measures need to be taken to protect against this.

Flywheels make far more sense for fixed installations. They don't need
to be gimballed, or handle shock or vibration (short of an earthquake).
They can be be buried, to safely contain the debris in case of a failure.

But, an expensieve high-tech flywheel solution probably isn't needed for
peak energy storage in a fast charging station. Batteries are going to
be cheaper and safer. Batteries that are old, used, or have too low a
performance for in-car use will still work fine. Even traditional
lead-acid batteries would work, as size and weight don't matter for a
stationary application. There are lots of industrial-strength lead-acids
that last for decades can happily deliver 1000+ amps.

--
It is vanity to do with more that which can be done with less.
         -- William of Ockham
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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Re: Fast Charging... (Flywheel?)

Electric Vehicle Discussion List mailing list
In reply to this post by Electric Vehicle Discussion List mailing list
Tesla does load balancing and load limiting at its superchargers. Although most of their stations are rated at 120, 135, or 145 kW, they usually deliver less based on these factors:

-utility ordered power limits. Drivers see this when their low SoC cars start out with high kW and in under a minute that drops into the 60s. Presumably Tesla is on a rate plan that requires load curtailment when the utility asks for it.

-equipment overheating of either the superchargers themselves or charging handles. Sometimes drivers switch station stalls in an attempt to work around this.

-shared power between two charging stalls. Earliest car gets priority. Reminder goes to second car. Stalls are labeled so drivers can avoid using the paired stall if they so desire.

-battery BMS. The BMS limits charge rates. Owner gathered info says factors include battery SoC, battery model (kWh rating), version (v1/v2/etc), chemistry (silicon added or not), age (time/days/months), usage (lifetime kWh in/out), health (usable energy vs design energy), temperature (above 40-50 F, below 90?), and probably other factors.


Some these same things have been done with certain OpenEVSE builds.


On February 8, 2018 10:20:13 AM CST, Dan Kegel via EV <[hidden email]> wrote:

>On Wed, Feb 7, 2018 at 2:30 PM, Robert Bruninga via EV
><[hidden email]> wrote:
>> I wonder how big a flywheel is needed to store the energy to charge a
>250
>> mile range in 20 minutes?
>> Since it is fixed, and does not have to be in a vehicle, it might be
>the
>> answer to large charging stations.
>>
>> When ten TESLAs pull up at ten fast charge cords at the same time,
>that is
>> over a megawatt of needed power... in 20 minutes...
>
>That application doesn't capitalize on the flywheel's ultrafast
>charging and discharging abilities.
>And smoothing can be done by modulating the teslas' charging rates.
>
>But hey, who knows.  See
>https://scholar.google.com/scholar?as_ylo=2014&q=flywheel&hl=de&as_sdt=2005&sciodt=0,5&cites=16378509166563059026&scipsc=1
>for recent related papers.
>- Dan
>_______________________________________________
>UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
>http://lists.evdl.org/listinfo.cgi/ev-evdl.org
>Please discuss EV drag racing at NEDRA
>(http://groups.yahoo.com/group/NEDRA)
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