However we do have a good analogy in the study below that compares the performance of ethanol used in an ICE or used to provide electricity for electric vehicles. The conclusion is that it is better to burn the hydrocarbon for electricity for EVs than to put it an an automobile's internal combustion engine.
In general, an electric vehicle powered with the typical coal natural gas mix in the grid will have approximately the same carbon emissions as an ICE auto getting about 50mpg. Of course that increases with any noncarbon generation added to the grid. In contrast, Ford might think they can provide consumers with vehicles that get 50mpg but I have to ask where do they go from there? That is the lower limit for electrics and it is the upper limit for internal combustion engines.
However that misses a much more important point, which is that electric vehicles are an enabling technology for a renewable grid. In aggregate an electric vehicle fleet represents a vast storage resource that enables large and rapid increases in renewable power generation.
Published Online May 7, 2009
Science DOI: 10.1126/science.1168885
Science Express Index
Reports
Submitted on November 24, 2008
Accepted on April 15, 2009
Greater Transportation Energy and GHG Offsets from Bioelectricity Than Ethanol
J. E. Campbell 1*, D. B. Lobell 2, C. B. Field 3
1 College of Engineering, University of California, Merced, CA 95344, USA.; Sierra Nevada Research Institute, University of California, Merced, CA 95344, USA.
2 Program on Food Security and the Environment, Stanford University, Stanford, CA 94305, USA.
3 Department of Global Ecology, Carnegie Institution of Washington, Stanford, CA 94305, USA.
* To whom correspondence should be addressed.
J. E. Campbell , E-mail: ecampbell3{at}ucmerced.edu
The quantity of land available to grow biofuel crops without impacting food prices or greenhouse gas emissions from land conversion is limited. Therefore, bioenergy should maximize land-use efficiency when addressing transportation and climate change goals. Biomass could power either internal combustion or electric vehicles, but the relative land-use efficiency of these two energy pathways is not well quantified. Here, we show that bioelectricity outperforms ethanol across a range of feedstocks, conversion technologies, and vehicle classes. Bioelectricity produces an average 81% more transportation kilometers and 108% more emissions offsets per unit area cropland than cellulosic ethanol. These results suggest that alternative bioenergy pathways have large differences in how efficiently they use the available land to achieve transportation and climate goals.