Just to clear up a couple of points from Jed Rothwell's post:
> 1. Electric cars consume much less energy per mile so there is not as much pollution in the first place. This is not the correct comparison to make! Both future car designs, in the correct comparison, will be electric -- and will have identical drive trains -- so the energy per mile is identical; and the comparison then is between having one vehicle: a.) operate solely on batteries, such as the Volt b.) and the other one operate on batteries most of the time, yet carrying a small diesel engine (motorcycle sized) to recharge the batteries in an emergency or for the occasional long trip. Due to the high cost of lithium batteries, option b.) would cost less, give greater security, and could be accomplished with low cost SLA batteries, for far less upfront cost than lithium. The downside of option b.) is that the diesel would need to come on for the last few miles of a long commute (but never for the trips to the grocery store etc.) Plus the big advantage is that option b.) is doable for probably $20,000 with SLA batteries- versus the lowest possible cost of the PHEV (which of course, will come down significantly once higher volume is achieved). Still many customer would rather have the security of NOT running out of juice on the freeway if the lithiums did not get a full charge; and another big advatave is being able to take a vacation by car without renting a vehicle to do it. And it is not either/or. There will be a big market for both types. In the end: option b.) should emerge as the mass market in terms of volume due to lower cost and flexibility. > 2. Pollution abatement at most power plants is much better than for individual automobiles (except for CO2 of course). That would only be true without the catalytic converter, it seems. Or do you have a reference for that? At any rate, if the backup ICE is seldom used, the issue is moot. > 3. A large fraction of electricity comes from pollution-free sources such as nuclear power and hydroelectricity. On a National average this is what? 35% in the USA ? This is not a large fraction. > In some states, at nighttime when cars will be recharged, nearly all > electricity comes from baseline nuclear power plants, or wind power in Texas. But even in those areas with nuclear power, many consumers would like to have the backup security of a small diesel. The SLA batteries which are used, would still charge at night, only for less time as they only need to give you half the range or less. >The diesel will actually get better net efficiency - than going from >grid-->home-->batteries-->vehicle, because of all the loses at every >step -- so there is even less net pollution than with the Volt. > JR: I doubt it. I have read they are about equal. Certainly not if the electricity if generated with uranium or wind. Electric power generation efficiency is improving faster than automobile engine efficiency, as old coal-fired plants are being phased out and more wind power comes on line. If the US builds 10 or 20 more nuclear power plants it will be very difficult for any form of ICE to rival electric power for low pollution. Again - this comparison is being mis-stated. It should not be about the PHEV compared to the ICE, but instead it is about the optimum design for a hydrid - which need NOT be the all battery PHEV version. A small ICE combined with maybe 6-8 standard SLA batteries makes the most sense of all IMHO -- even if the ICE (in reserve) is only used by the driver infrequently.... in fact, the goal would be to design it so that it used very infrequently, but it is still always there if you need it. Jones
