Quote:
Originally Posted by Ecky
Would it be reasonable then to say that a 100MPGe car running on coal-generated electricity from a plant that's 40% thermally efficient would actually be 40MPGe, in a sense? Or, less really because it takes energy to get that coal out of the ground, transported, and prepped for burning, plus whether systems are necessary to clean up emissions?
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Not so sure about coal, since gas is also quite energy-intensive from the oil well to the pump, going through the refining. But in regard to ethanol, that is also subject to different brewing processes according to the feedstock (here in Brazil it relies mostly on sugarcane, even though corn is also used in Mato Grosso state when it's not sugargane season), and the energy balance that is also tied to the feedstocks. Anyway, since both gas and ethanol are sold by gallons, why bothering about a gallon-equivalent for ethanol? OTOH since electric power can't be measured by volume (not getting into an argument about the energy density of the battery packs, that's another field), it makes more sense to talk about MPGe.