by yesplease » Thu 22 Oct 2009, 19:04:21
$this->bbcode_second_pass_quote('Pops', '[')url=http://www.transportation.anl.gov/pdfs/TA/559.pdf]Here is a study[/url] that I think says electric vehicles use less fossil fuel unless fossil fuel is used to generate electricity.
Be careful about mixing FF use and GHG emissions. They are only identical if we're using the same fuel. If we're comparing fuels, and have the the difference in GHG emissions, in order to get the difference in energy consumption we need to multiply by the ratio of Carbon
emissions intensity. For example, no matter what, there's an advantage in terms of energy consumption when comparing EVs and hybrids, but that drops as FFs become a greater part of the generating mix. Otoh, because coal has a good 33% more Carbon per unit energy, EVs may have greater GHG emissions than hybrids in coal heavy markets.
$this->bbcode_second_pass_quote('', 'T')he reduction in total energy consumption in CD relative to CS operation progressively diminishes as the electricity generation mix changes from the California to the U.S. and Illinois mixes, respectively. Furthermore, the WTW GHG emissions advantage of CD over CS operation disappears by moving from the California to the U.S. generation mix, and it is even reversed by moving to the Illinois marginal generation mix, thus surrendering the potential GHG emissions benefit of PHEVs (except for the case of hydrogen when produced via electrolysis).