Will Electric Vehicles Work For Us?

On Fri, 19 Jan 2007 10:08:29 +0000, Eeyore
> wrote:

>
>
>Dave Head wrote:
>
>> On Thu, 18 Jan 2007 20:54:39 -0600, (Matthew T.
>> Russotto) wrote:
>>
>> >In article >,
>> >Dave Head > wrote:
>> >>OK, lets say that a viable electric vehicle is on the horizon:
>> >>
>> >>http://money.cnn.com/2006/09/15/tech...biz2/index.htm
>> >>
>> >>The idea is to charge it up and it'll run for 300 miles. It can be fully
>> >>charged in 5 minutes.
>> >
>> >Hmm. "it will charge up in five minutes and provide enough energy to
>> >drive 500 miles on about $9 worth of electricity". Average cost of
>> >electricity is roughly 10 cents per kilowatt/hour. So $9 of
>> >electricty is 90kWh. Dump that into a car in 5 minutes and you're
>> >pumping about 1 megawatt of power into the car. Color me skeptical.
>>
>> Well, its a capacitor. Capacitors are very good at flowing big current, in or
>> out. Capacitor at 3,500 volts is 285 amps for a megawatt. Yes, there better
>> be a hefty substation standing near the recharging station, and yes, they
>> better figure out a really safe way to do that without frying people
>> accidentally. I still favor the remove and replace the power source and charge
>> it elsewhere model. Remove the capacitor, charge it indoors, in the dry, by
>> robots that can't be electrocuted. People shouldn't be handling this sort of
>> voltage.
>
>Some modern battery technologies can accept charge that fast too.
>http://www.a123systems.com/html/technology.html
>
>Graham

Well, great! Electric cars are going to happen, sooner or later, and they'll
be high enough power that we're gonna like 'em. Efficient solar PV is going to
happen, eventually... Stuff's happening, and the future looks really bright, I
think.

Dave Head

Dave Head wrote:

> Eeyore > wrote:
> >Dave Head wrote:
> >> (Matthew T. Russotto) wrote:
> >> >Dave Head > wrote:
> >> >>OK, lets say that a viable electric vehicle is on the horizon:
> >> >>
> >> >>http://money.cnn.com/2006/09/15/tech...biz2/index.htm
> >> >>
> >> >>The idea is to charge it up and it'll run for 300 miles. It can be fully
> >> >>charged in 5 minutes.
> >> >
> >> >Hmm. "it will charge up in five minutes and provide enough energy to
> >> >drive 500 miles on about $9 worth of electricity". Average cost of
> >> >electricity is roughly 10 cents per kilowatt/hour. So $9 of
> >> >electricty is 90kWh. Dump that into a car in 5 minutes and you're
> >> >pumping about 1 megawatt of power into the car. Color me skeptical.
> >>
> >> Well, its a capacitor. Capacitors are very good at flowing big current, in or
> >> out. Capacitor at 3,500 volts is 285 amps for a megawatt. Yes, there better
> >> be a hefty substation standing near the recharging station, and yes, they
> >> better figure out a really safe way to do that without frying people
> >> accidentally. I still favor the remove and replace the power source and charge
> >> it elsewhere model. Remove the capacitor, charge it indoors, in the dry, by
> >> robots that can't be electrocuted. People shouldn't be handling this sort of
> >> voltage.
> >
> >Some modern battery technologies can accept charge that fast too.
> >http://www.a123systems.com/html/technology.html
> >
> >Graham
>
> Well, great! Electric cars are going to happen, sooner or later, and they'll
> be high enough power that we're gonna like 'em.

I'm sure this will happen in due course.

The main hurdle remains battery technology.

The main criteria are.....
Energy density by weight
Energy density by volume
Ability to accept fast charge ( and discharge ) - which is related to 'power density'
Efficiency in the charge-discharge cycle
Maximum lifetime in years
Lifetime in charge-discharge cycles
Lifetime reduction through fast charging
Self discharge rate


> Efficient solar PV is going to happen, eventually...

Price is actually more important. Due to quantum effects I think the max theoretical
efficiency lies roughly in the 30-40% range. About double to 3 times what's currently
commonly available.


> Stuff's happening, and the future looks really bright, I think.

Check out CIGS solar e.g.
http://www.isetinc.com/cigs.html
http://www.nanosolar.com/products.htm

Graham

Dave Head wrote:

> Eeyore > wrote:
> >Dave Head wrote:
> >
> >> I _still_ don't think it would be ANYWHERE as expensive as y'all were
> >> speculating because _somebody_ is gonna figger out a cheap way to orbit and
> >> then things will get simple.
> >
> >There are finite limits ( of physics ) that determine the amount of energy to do
> >that and the numbers are horribly big. That is truly the biggest problem.
> >
> >Graham
>
> Naw, not a problem. We _have_ horribly big amounts of energy to throw stuff
> into orbit. Our only problem is capturing the energy we have and using it.
>
> 'Fer instance, the Navy base where I work just tested a new 8 megjoule railgun.
> The thing, when perfected, is expected to throw ordnance 200+ miles and the top
> of the trajectory will be 95 miles.

In which case the shell must weigh < ~ 6kg. I didn't even factor in losses due to air
resistance either.


> That is outer space.

Is it ? Only just !


> If you threw a
> rocket up there, it would only have to burn to gain the added orbital velocity
> and orbit circularization energy and presto, orbit.

How about an orbital gun then ?

Graham

Eeyore > writes:
>Bernd Felsche wrote:
>> Eeyore > writes:
>> >Bernd Felsche wrote:

>> >> It won't "be fully charged in 5 minutes".

>> >Probably not !

>> >I did some sums a while back in one of the energy groups that
>> >showed that 2 hours was realistically do-able though.

>> Not for the 400MJ of recoverable storage when plugged into a
>> "domestic" outlet.

>> It's serious, industrial-grade loading.

>A 30kWh battery ( suitable for hybrids with ~ 100+ mi range on
>electric only ) presents no problem to recharge in 2 hours from a
>domestic supply.

Where? Which? The Tesla's _partly_ discharged battery takes 2 hours
to re-charge after a 100-mile trip - out of the claimed range of 250
miles. Based on a simple, linear rule of thumb; charging is
therefore at 10kW.

>Likwise a 100kWh battery could be recharged overnight.

How does that scale to every house in the street charging?
What happens when everybody in the neighbourhood turns on every
electrical appliance in the house?

>> >There are actually some 'new technology' batteries that can be
>> >recharged in 5 mins or so though !
>>
>> Which ones? How efficiently can they be charged?
>> And will they hold that amount of charge indefinitely?

>http://www.a123systems.com/html/technology.html

Sure... it'd only take 13,000 cells to make one traction pack.
And 13,000 (10A) power transistors to control the charge and
discharge from each cell.

High charge rates appear to decrease life by at least 20%.

Sometimes a "free lunch" can be far too costly.
--
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | "If we let things terrify us,
X against HTML mail | life will not be worth living."
/ \ and postings | Lucius Annaeus Seneca, c. 4BC - 65AD.

Eeyore > writes:

>Initially I'd expect EVs *not* to be taxed much in order to
>encourage take up. This is happening in the UK already with EVs
>exempted from London's congestion charge for example. That is
>potentially worth thousands a year alone.

Save money on both. Don't visit London.

I won't despite it not being too unpleasant before Red Ken screwed
up the traffic flows to "justify" the CC.
--
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | "If we let things terrify us,
X against HTML mail | life will not be worth living."
/ \ and postings | Lucius Annaeus Seneca, c. 4BC - 65AD.

Eeyore > writes:
>Dave Head wrote:

>> I _still_ don't think it would be ANYWHERE as expensive as y'all
>> were speculating because _somebody_ is gonna figger out a cheap
>> way to orbit and then things will get simple.

>There are finite limits ( of physics ) that determine the amount of
>energy to do that and the numbers are horribly big. That is truly
>the biggest problem.

Look, if the alleged flooding occurs due to global warming, it'll
cover more land and increase albedo (light reflected back into
space), reducing the amount of heat from the sun and cooling the
climate.

This little planet has been looking after itself for several
thousand million years and has over the past 10 million or so
settled into a comfortable lifestyle punctuated by the occassional
cold or fever.
--
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | "If we let things terrify us,
X against HTML mail | life will not be worth living."
/ \ and postings | Lucius Annaeus Seneca, c. 4BC - 65AD.

Eeyore wrote:
> Dave Head wrote:
>
> > Eeyore > wrote:
> > >Dave Head wrote:
> > >
> > >> I _still_ don't think it would be ANYWHERE as expensive as y'all were
> > >> speculating because _somebody_ is gonna figger out a cheap way to orbit and
> > >> then things will get simple.
> > >
> > >There are finite limits ( of physics ) that determine the amount of energy to do
> > >that and the numbers are horribly big. That is truly the biggest problem.
> > >
> > >Graham
> >
> > Naw, not a problem. We _have_ horribly big amounts of energy to throw stuff
> > into orbit. Our only problem is capturing the energy we have and using it.
> >
> > 'Fer instance, the Navy base where I work just tested a new 8 megjoule railgun.
> > The thing, when perfected, is expected to throw ordnance 200+ miles and the top
> > of the trajectory will be 95 miles.
>
> In which case the shell must weigh < ~ 6kg. I didn't even factor in losses due to air
> resistance either.
>
>
> > That is outer space.
>
> Is it ? Only just !
>
>
> > If you threw a
> > rocket up there, it would only have to burn to gain the added orbital velocity
> > and orbit circularization energy and presto, orbit.
>
> How about an orbital gun then ?
>
> Graham

Yes, but better still is to stick it on the moon. From there, material
could be launched with solar power and part of the moon itself to the
L1 point between the sun and the earth. This is, of course, future
stuff - stuff to be done in 20 - 40 years from now, when technology has
made things orders of magnitude cheaper.

Dave Head

Bernd Felsche wrote:

> Eeyore > writes:
> >Bernd Felsche wrote:
> >> Eeyore > writes:
> >> >Bernd Felsche wrote:
>
> >> >> It won't "be fully charged in 5 minutes".
>
> >> >Probably not !
>
> >> >I did some sums a while back in one of the energy groups that
> >> >showed that 2 hours was realistically do-able though.
>
> >> Not for the 400MJ of recoverable storage when plugged into a
> >> "domestic" outlet.
>
> >> It's serious, industrial-grade loading.
>
> >A 30kWh battery ( suitable for hybrids with ~ 100+ mi range on
> >electric only ) presents no problem to recharge in 2 hours from a
> >domestic supply.
>
> Where? Which? The Tesla's _partly_ discharged battery takes 2 hours
> to re-charge after a 100-mile trip - out of the claimed range of 250
> miles. Based on a simple, linear rule of thumb; charging is
> therefore at 10kW.

Yes, that's what I said pretty much. I used 15kW actually.


> >Likwise a 100kWh battery could be recharged overnight.
>
> How does that scale to every house in the street charging?
> What happens when everybody in the neighbourhood turns on every
> electrical appliance in the house?

Every appliance running *overnight* ?


> >> >There are actually some 'new technology' batteries that can be
> >> >recharged in 5 mins or so though !
> >>
> >> Which ones? How efficiently can they be charged?
> >> And will they hold that amount of charge indefinitely?
>
> >http://www.a123systems.com/html/technology.html
>
> Sure... it'd only take 13,000 cells to make one traction pack.
> And 13,000 (10A) power transistors to control the charge and
> discharge from each cell.
>
> High charge rates appear to decrease life by at least 20%.

Yes, there's trade off. You don't need to fast charge all the time though.

Graham

Bernd Felsche wrote:

> Eeyore > writes:
>
> >Initially I'd expect EVs *not* to be taxed much in order to
> >encourage take up. This is happening in the UK already with EVs
> >exempted from London's congestion charge for example. That is
> >potentially worth thousands a year alone.
>
> Save money on both. Don't visit London.
>
> I won't despite it not being too unpleasant before Red Ken screwed
> up the traffic flows to "justify" the CC.

Apparently traffic flows are fine.

Graham

Bernd Felsche wrote:

> Eeyore > writes:
> >Dave Head wrote:
>
> >> I _still_ don't think it would be ANYWHERE as expensive as y'all
> >> were speculating because _somebody_ is gonna figger out a cheap
> >> way to orbit and then things will get simple.
>
> >There are finite limits ( of physics ) that determine the amount of
> >energy to do that and the numbers are horribly big. That is truly
> >the biggest problem.
>
> Look, if the alleged flooding occurs due to global warming, it'll
> cover more land and increase albedo (light reflected back into
> space), reducing the amount of heat from the sun and cooling the
> climate.

Yes.


> This little planet has been looking after itself for several
> thousand million years and has over the past 10 million or so
> settled into a comfortable lifestyle punctuated by the occassional
> cold or fever.

Sure.

Graham