


Elon Musk
However, study fails to account for certain critical aspects









Outside cost, other issues are also worth noting, though.


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RE: You do the math!
By Netjak on 6/1/2010 12:25:49 PM , Rating: 2
EV's 80% efficiency puts them on par with latest conventional ICE's (gas or diesel).

Overal, power plants works on 40%+ efficiency, minus distribution losses, minus EV losses gives nothing better than conventional gas engine plus enviromental risks of battery production increase. As u pointed out, it's matter of location of polution.

Power plants are long lasting; they are rarely updated. Car makers do update their engines allmost every other year; from 1990 til now, they cut emissions 100-fold, efficiency increased 30%.

RE: You do the math!
By Keeir on 6/1/2010 5:48:17 PM , Rating: 2
Netjak. That hurts my head.
A full electic is able to get ~4 miles per kWh from the wall (Tesla Roadster claims 3.6, Nissian Leaf claims 4.5). PHEV, saddled with gasoline engine's mass etc, get 3.5 miles per kWh (Volt claims 4.4, Prius claims 3.3).
US power grid is 92% efficient. US coal power plants are on average 33% efficient.

To go 1 miles a Full Electric consumes
0.82 kWh
a PHEV (on electricity) consumes
0.94 kWh

In constrast, the distallation of crude oil to gasoline is only 82% efficient. Gasoline has around 33 kWh of energy per gallon. If we assume that gasoline magically gets from refinery to the pump,

A 30 MPG car requires
1.34 kWh per mile
A 50 MPG car requires
0.80 kWh per Mile
(A Diesel requires ~55 MPG to get 0.80 kWh)

In conclusion, an Electric Car powered entirely by Coal power plants built prior to say 1980 is on par energy efficieny wise to the most modern Clean Diesel and Hybrid Gasoline cars. Of course, in the US, only ~50% of the power is provided by Coal. Once you mix in Natural Gas, etc the picture gets significantly better.

All of this of course hangs on the question: How much Natural Gas and electricity are used to actually refine a gallon of gas, US DOE seems to suggest with thier
82%" figure at most 5.9 kWh. Nissan has recently claimed 7.5 kWh are used for a single gallon. Which to believe? I am not sure, but it is clear to me that a normal car uses a significant amount of electrical energy... potentially if Nissan is correct, as much as a full EV.

Note: US department of Energy is the source for all the figures.

RE: You do the math!
By Netjak on 6/2/2010 4:03:48 AM , Rating: 2
Your figures are correct.
However, you mentioned energy consumption during refining of gasoline, but not energy use in transporting and processing of coal and waste in the plant. 33% figure is for thermal, not overal efficiency.

Efficiency wise, EV's are on their top, power plant is only place for progress (which is painfully slow).

EV's are distant future when we will be able to generate electricity from some other source.

