Re: Cost per mile over 10 yr life?


"Tim Keating" <NotForJunkEmail@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:b9v891dnv6tbntancu08itnfli4v7cervs@xxxxxxxxxx

> >In my own calculations assuming a NiMH battery pack it would seem on a
> >$/mile basis a comparable electric car won't have any chance until the
price
>
> NiMH is not the best solution for a pure EV.. (Not an energy efficient
> technology, see page 21 of "15_Batteries.pdf" link supplied below).


>From a technological point of view, I would tend to agree NiMH batteries are
in many ways inferior to Li-Ion for electric vehicle use. On the other
hand, the overall operating cost (which factors in capital cost, interest,
electricity/fuel cost, maintenance costs, etc.) is the single most important
parameter determining a given electric vehicle's practicality. In this
regard, it would seem that at the moment using today's technology NiMH cells
deliver distinctly lower $/kWh figures than Li-Ion. As a consequence I
consider NiMH batteries to be a better overall choice, although that isn't
to say Li-Ion or other technology can't have a place in the electric vehicle
market.


> No.. Li-ion is way more efficient.. Charging is more efficient.
> (Recent breakthrough extend the cycle lifetime >100x).
>
> http://web.mit.edu/2.009/www/lectures/15_Batteries.pdf


I don't disagree that Li-Ion may deliver higher charge/discharge electrical
efficiency than NiMH. Neverthless electricity is a relatively minor cost of
operating an electric vehicle. The most practical design therefore won't
necessarily have the absolute lowest operating cycle efficiency.


> Variable motor speed controls are in 93%+ category.

Some motors do claim impressive efficiencies in the 90's% range. On the
other hand these figures are usually the peak motor efficiency and only
apply for a certain range of motor loading conditions. Given the variable
loading nature of common driving, this doesn't guarantee an average
efficiency of over 90%. Motor controllers can be made greater than 99%
efficient depending upon topology selected, the battery pack voltage, and
how much the engineer optimizes for efficiency (keep in mind increases in
some categories often have trade offs in others, such as cost). Whatever
the case, overall the motor + controller efficiency is still very good.

The powerplant thermodynamic efficiency is the lowest in the overall cycle.
As a consequence, it dominates the overall cycle efficiency. Unfortunately
Mr. Carnot really messed things up for everybody. Maybe it isn't fair to
blame him for all our problems...


> Currently EV's use about 140wh to160wh per mile with room for
> improvement. We dedicated designs we could probably get that number
> down to 100wh per mile.
>
>
http://media.mitsubishi-motors.com/pressrelease/e/corporate/detail1269.html


That may be true, but these designs all represent the ultimate in econo-box
technology.

The Geo Metro/Chevy Metro/Chevy Sprint was sold in the US for a number of
years, but its sale has since been discontinued. They simply weren't
profitable enough to continue selling them. They had such a low intitial
purchase price they weren't worth much to sell, and few people were buying
them. They realisitcally delivered 40-45 MPG and had a new purchase price
of less than $10,000.

So why didn't people buy them? It wasn't because they "were too expensive"
or that they had "too low gas mileage." In fact, it was rather the
opposite. Typical US citizens work hard and make lots of money. What do
they do with all that excess money they make? They spend it on luxuries.
In other words, they spend it on things that aren't required for basic human
survival, but they are fun to own/buy anyway.

Automobiles happen to be one of the particularly important luxuries that
people buy. Owning and operating a large SUV obviously isn't the most
practical transportation method. Compared to the Geo Metro, they really
deliver something like 1/3 the gas mileage simultaneous with 3X the initial
purchase price. I can't really blame SUV owners for buying them though. If
you spend all your life driving a small car, the very first time you sit
behind the wheel of a large SUV or pickup truck is an interesting
experience.

The first thing you notice is how incredibly high off the ground you are.
This gives you tremendous visibility of the road. You can see right over
the top of all the cars out there, and so you can really see what is going
on. The first time you press hard on the gas it is hard not to develop a
little smile. The engine roars loudly and you can feel the huge amount of
power at your disposal. All in all, you can't help but develop a
subconcious feeling that you are a like God. You are high off the ground,
you have tremendous power at your disposal, you are relatively "all seeing",
and you simply feel like you have status, importance, and invincibility.

This contrasts very sharply with sitting behind the wheel of a Geo Metro or
other econo-box type of car. Getting into a little pipsqueak box with a
little pipsqueak engine does not make you feel Godlike. Further, (at least
in the US) people who own Geo Metros are publicly ostracized by their
friends and family. It just isn't socially "cool" to drive an econo-box,
even if it is much more economical and much friendlier on the environment.

So this is the reason why the Geo Metro had no place in the US auto market.
Similarly this is part of the reason why electric vehicle designs like the
GM EV1 haven't historically had much place in the US auto market. Some
people criticize GM management for not putting any real effort into making
the EV1 a sucess. I personally think this criticism is unjust. The GM EV1
had all of the market disadvantages of a econo-box car, while having none of
the "economy" advantages. The car was overall significantly more expensive
to own and operate than even a "luxury" type (not very economical) gasoline
car. Additionally, it had serious disadvantages compared to any gas car,
namely an inability to go more than 70 miles. The managers of GM understood
these problems, and they knew right from the very beginning (even before
making the car) that there was no way the vehicle could ever make it on its
own in the US marketplace. The car was always nothing more than a big
public relations stunt and research project. If it was ever intended to be
more than this, they would have made more of them (only made a few hundred
total IIRC), and they would have allowed people to actually buy them instead
of leasing them.

The managers of GM knew the car wouldn't be practical, but they wanted to
research how exactly impractical it would be. After building the car they
have gained internal experience and expertise with electric vehicle
technology. In this sense they get benefit in that they will be a step
ahead of other auto manufacturers if and when electric vehicles ever become
competitive and practical in the US auto market. Similarly they obtained
obvious positive press for making that car. The project did therefore have
some tangible benefits which made the managers believe it was an effort
worth wasting money on.


So back to the topic at hand. While it is great if you can super optimize a
car design for extremely low power usage, ex: 100 Wh/mile, that doesn't
necessarily mean all that much since it entails making the car an ultimate
econo-box. If on the other hand the US and world become sigificantly poorer
as a consequence of depleting fossil fuel supplies, then maybe people won't
have so much money buring holes in their pockets. In that case, extreme
high efficiency econo-box cars may become much more popular.

On that note, it is very important when making comparisions between gasoline
and electric vehicles to try to do things as apples to apples as possible.
For example, the economic competitiveness (in terms of $/mile all costs
considered) of a tiny econo-box electric car should not be compared against
a large gasoline SUV. So, an econo-box electric car is much more fairly
compared against the Geo Metro. Given the very high performance and very
low cost of the Geo Metro, electric cars have a high bar of performance to
meet or exceed.


> Other Items..
> Oil derived fuels will soon not be available to many consumers.
>
> Thus one must factor in the losses and cost equivalents of making a
> suitable fuel for those vehicles from coal. Then there are the
> environmental aspects of using all that carbon.
>
> Ultimately, we will need to create transportation technology which
> is not totally dependant on using carbon based fuels.


All likely quite true.



> >With today's technology it might even be possible to make EVs overall
> >cheaper to operate over a person's lifetime than internal combustion
engine
> >vehicles. Maybe... It would have to be done right.
> >
>
> You have yet to apply an scale of economies to any of your calcs..
> Batteries become cheaper.. (especially when they start recycling
> materials).
> Electronics become cheaper..


In my mind a "practical" electric vehicle based on NiMH technology currently
available already obtains great advanage from economy of scale. I contend
that NiMH batteries will not likely be able to drop sigificantly below
$200/kWh storage without any advancements in technology. Obviously mass
production/economy of scale cannot reduce the battery pack to less than the
cost of the materials that go into it. Given the energy density of typical
NiMH batteries, a "pracical" battery pack may weigh somewhere around 500kg.
If we assume it is a big chunk of pure nickel, and if we assume nickel costs
some $10,000 per metric ton (the price varies quite a bit over time though),
then the battery pack has a materials cost of $5000. Given that I already
claimed in my previous post that a reasonably size battery pack would cost
around $7000, it would appear NiMH batteries are already not that much more
expensive than their component materials. As a consequence economy of scale
would not really be able to help much. Instead, economic theory would have
you believe that increased demand for nickel (if we were to make NiMH EV
batteries on a massive scale) would cause the equillibrium price of nickel
to rise. As a consequence, it would even be possible making EVs on a very
large scale could cause them to become even more expensive.

Of course, this is a bit simplified. NiMH batteries aren't pure nickel
metal. One of the electrodes is made of nickel hydroxide, and the other one
of typically some "AB5" (5 is subscript) type metal hydride. "AB5"
basically is a symbol representing a structure of one atom of element "A"
alloyed with five atoms of element "B". Typically lanthanum or similar rare
earth metal is used for element "A" and nickel is used for element "B". So
the metal hydride is typically LaNi5. This structure can store up to six
hydrogen atoms each. Some nickel metal hydride batteries use some other
type of metal hydride for hydrogen storage. The cell also contains an
electrolyte of potassium hydroxide mixed with some other stuff.

So... By mass nickel is the primary ingredient of NiMH cells, however,
lanthanum or other rare earth metals are fairly expensive, so they do
contribute noticeably to the cost. All things considered, I wouldn't hope
for mass production to greatly reduce the price of NiMH cells to less than
$200/kWh without any technological improvements. Research is taking place
however, and research into hydrides for the "hydrogen economy" could produce
a cheaper and superior hydride material. If these research efforts pay off,
we may see NiMH cells with distinctly superior capacity (maybe triple todays
best???) along with lower cost and possibly better cycle life.



> Additional EV advantages over ICE vehicles.
> Overall design is much simpler..

Well... The powertrain itself is certainly simpler (and can, if properly
designed, last practically forever). The infrastructure and chicken/egg
problems are not.


> Weight is significantly reduced..

Well... If you stick a small Li-Ion battery pack in it, weight could be
reduced. But then, so too will performance be reduced. The lead acid GM
EV1 had a curb weight of 2922 lbs. This obviously doesn't compare favorably
with the Geo Metro at around 1830 lbs., or your more typical compact size
cars at 2400 lbs.


> No power train, emiision(catalyitc conv), noise
> reduction(muffler),

Valid.

> low voltage electrical generation/storage, or


Ideally for ultra rapid charge EVs, the battery pack voltage should be as
high as possible. Otherwise the current required rapidly becomes
unmanageable since the hook up cables would not really be easily managed by
non-muscular people. Since 1200V Insulated Gate Bipolar Transistors (IGBTs)
are readily available and offer excellent bang for the buck, I suggest a
maximum in use battery pack voltage of about 1000V or somewhat less. Even
with a ~1000V battery pack I estimate it would take something of around 4/0
gauge or bigger braided copper straps (thin and flat) to remain reasonably
flexible while still being able to cope with the current required to charge
from 0-80% in around 3 minutes. At the charger to car interconnect you
would need several over temperature cutouts in case poor electrical contact
is made. The power demand would be massive, but nevertheless things could
be accomodated with today's technology in some form or another. The charger
would likely need to provide a source of circulating cooling water too keep
the batteries reasonably cool while under super charge.

Unfortunately the electrical demand for ultra rapid charging an electrically
powered semi-truck battery pack in 3 minutes would be rather impractical.
This is especially so if you wanted to charge more than one simultaneously
at a given "gas station."

At home overnight chargers wouldn't need to be anywhere near so fancy for
ordinary sized cars.


> thermal energy waste management systems which results in smaller
> tires, suspension, frame, brakes, steering, etc..
> Standby braking system lasts lifetime of car.
> A/C lasts lifetime of car.
> ( Hermetically sealed compressor replaces non-sealed versions)

There is no engineering reason why current A/C systems can't reliably be
made to last the lifetime of gasoline cars. There are plenty of
refrigerators and house air conditioners that have been in use for decades
without any problems. Of the automotive A/C systems I have seen fail, it
seems leaking refrigerant is the most common problem. Of those systems
which I have been able to identify where the leak is from, it seems the
service ports are a common culprit.


> Primary charger/(inverter?) located in parking facilities.
> (re-used for many vehicles over it's lifetime.)


Chargers aren't free. Personally I like the idea of having an automatic
charger at home which doesn't require plugging in. Perhaps the charger
might come in the form of a platform you stick in your driveway and park on
top of. After you are done parking a telescoping object rises up and out of
the platform and makes physical contact with the bottom of the car. No
electrical contact is made but they are magnetically coupled when together.
Energy can be supplied inductively much like with the GM EV1 charger paddle.
Some control system is needed to insure you park properly to insure good
alignment between charger and car. Alternatively the telescoping part
should be able to robotically move around to some extent.

Ultra rapid chargers (~ 3 min.) should be located particularly along
interstate highways, with only a few in urban settings. Presumably urban
drivers live in or near the city, so they would do most of their charging at
home. Ultra rapid charging would only be necessary when driving your car on
long trips. The efficiency penalty and extra infrastructure required for
ultra fast charging would dramatically increase the price of that
electricity. However, since long trips are rather the driving exception
rather than the rule, that may not be much of a problem.


> Social issues can be solved
> Apartments can be required to install common use charging stalls.
> etc.. (Power usage/billing handled by utility via standardized
> power/optical data link between car and charger.)

Indeed these aren't insurmountable problems, but unfortunately they do
complicate the issue.


.

Relevant Pages

  • Re: Cost per mile over 10 yr life?
    ... >>>I used the numbers from my car. ... >vehicles, they are just far too impractical. ... >A 30kWh lead acid battery pack would be unacceptably large for a normal ... Electricity operating cost may still be lower though ...
    (sci.energy)
  • Jewish inventor-genius, Dean Kamen, going Sterling Green.
    ... year-old engine nobody else thinks can work. ... But when I first meet him, Kamen takes me out to the car park at Deka ... in theory it can turn any source of heat into electricity, ... When the Segway Personal ...
    (soc.culture.german)
  • Jewish inventor-genius, Dean Kamen, going Sterling Green.
    ... year-old engine nobody else thinks can work. ... But when I first meet him, Kamen takes me out to the car park at Deka ... in theory it can turn any source of heat into electricity, ... When the Segway Personal ...
    (soc.culture.israel)
  • Jewish inventor-genius, Dean Kamen, going Sterling Green.
    ... year-old engine nobody else thinks can work. ... But when I first meet him, Kamen takes me out to the car park at Deka ... in theory it can turn any source of heat into electricity, ... When the Segway Personal ...
    (talk.politics.mideast)
  • Electric cars quietly gaining acceptance
    ... with vehicles like the lightning-fast Tesla Roadster and the Wrightspeed X1, ... This car ain't no golf cart. ... the recently introduced Tango has loftier ambitions: ... With electricity usage costing about a ...
    (sci.energy)
Loading