Quote:
Originally Posted by jamesqf
Of course the calculation depends on where you start measuring, but if you're just considering the in-car powertrain, then electric is far more efficient than IC, which is about the least efficient way of turning fuel into energy.
Then too, I can't help but remember all the people who've said getting 70 mpg in ordinary driving was impossible :-)
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James,I located some brochures from Solectria I got at the Solar 500 back in the 90s.
For an 'in-car' efficiency,taking the 'best' of their products I came up with
Battery--------- 80 %
Controller------- 98 %
Motor----------- 98 %
So I agree with the 'in-car' assessment.
Looking at the 'total' energy balance,using a combined cycle coal-fired power plant for the electricity to charge the battery pack I get the following:
Power plant---------------------- 34 %----------- net 34 %
Grid------------------------------ 94 %---------- net 31.96 %
Battery Charger------------------- 90 %---------- net 28.764 %
Battery--------------------------- 80 %---------- net 23.011 %
Controller------------------------- 98 %---------- net 22.550 %
Motor----------------------------- 98 %---------- net 22.09 %
for a total net overall efficiency of 22.09 %
I ran the same genesis for a Solar Photovoltaic-powered electric car,using Space-grade Gallium Arsenide panels of 23 % conversion efficiency as the 'source' and calculated an overall energy efficiency of 17.6 %.
Reading 'The Zero Carbon Car' you're pulled into a de-fenestrated world where nothing exists beyond the electric car,and all up-stream inefficiencies are totally discounted.
The Mazda Miata glider chosen for their project while possessing only a frontal area of 17.7 sq-ft has an estimated Cd 0.45 as shown in the book.
As a gasoline car,this platform won't deliver over 42-mpg.As an EV it cannot deliver any better on an equivalent energy basis.
Southern California Edison rates EVs at 0.46 kWh/mile,not 0.25 as claimed in the book.