|MadSci Network: Engineering|
Your attitude is commendable, but I'm afraid what is "well enough" for you will not suit the average driver. Drivers have "expectations." One is at least 500 kilometers between stops for energy. A second is acceleration adequate to get onto high-speed thruways safely. A third is enough carrying capacity. And once these specifications are met, drivers never like to "go backwards." With gasoline having an energy density of 14 kilowatt-hours/kilogram, and a lead-acid battery having about 0.04 kilowatt-hours/kilogram, it is clear batteries have a disadvantage in the amount of "dead weight" and "dead volume" a 500 kilometer car would carry. A site that elaborates on this is: http://whyfiles.org/005electcar/4.html There is much written on what technologies automobiles may be moving toward. Hybrid (gasoline/electric) vehicles like the Honda Insight or the Toyota Prius promise excellent fuel economy and low pollution offset by higher initial cost. And both cars meet the "expectations" I mentioned previously. The Economist magazine, in a recent article on these hybrids, suggested these vehicles may be only transitional because something "better" is coming — the fuel cell. Not an ordinary fuel cell using hard-to-handle hydrogen — this one's based on liquid fuel (like gasoline and alcohol) with a "reforming" technology doing the hydrogen extraction. Under the battery-power electric car scenario, the current automobile energy distribution system using pipelines, rail, tanker boats and trucks would have to be scrapped. And (here's the fun part) car makers would have to standardize the battery packs in order to make for efficiency in the swapping you suggest. But a reforming fuel cell electric car would use gasoline or alcohol. And the existing energy distribution network could be used with modest modification. Here's an article optimistic on the technology: http://www.wired.com/wired/5.10/hydrogen.html I make no bets myself. But whatever we move toward has to meet some economic criteria and political pressures from the parties concerned and I hope will address pollution and conservation concerns. Larry Skarin
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