Re: "Well to wheel" electric car efficiency

On Sun, 25 Sep 2005 08:40:12 GMT, "Baby Elian" <xxx@xxxxxxxxxxx>
wrote:

>I assume that an electric car is not more efficient than 20% ("tank to
>wheel" - I leave out oil or fuels transport,refinement or preparation and
>distribution). If we assume 40% the efficiency in electric production,20%
>losses in
>trasformation and trasport of electricity,80% is the efficiency of the
>battery and 85% the electric motor,then the overall efficiency is

Your numbers are off by significant margins..

Li-ION .. 95% efficient.. (energy to charge verses energy output)
Pb2SO4 .. 75%
NiMH ... 65%..

Electric motor.. closer to 93% @ rated load
(Current EPAct standard for 50HP motor).
(NEMA premium is up to 95% efficient)..

EV can be recharged via local renewable energy source, (solar,
wind), where conversion efficiency has little meaning. (I.E. the same
resource will be avail tomorrow and the day after that, etc.. )

>22%,slightly higher than IC cars (I neglect the contribute of regenerative

Current automobiles fall into the 5 to 10% efficiency range..
(maybe less).. Unlike renewables, one must tack on all the energy
used in drilling, pumping, separating, transporting, refining,
defending, and distribution.

Note: the above number is dropping day by day.. As it is becoming
more costly (energy wise) day by day to recover oil from ground.. As
oil fields become depleted the water cut increases day by day.

some data points..
http://www.peakoil.net/iwood2003/ppt/SimmonsPresentation.pdf
http://www.naturalhub.com/fading_of_the_oil_economy_timeline.htm

>brakes).What do you think about,have you got different numbers (if
>possible,for vehicles having same power or performances)?

Even regenerative brakes have losses..
.

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