M_e, thanks for the reply.
In re: HEVs, the cost barrier would be equally high for either NiMH, liquid-electrolyte lithium-ion, or (so-called) lithium-polymer cells, would it not? It is possible that gov't tax breaks for HEVs could be an equalizing factor.
Your reply stimulated me to poke around, and while I'm still sifting through a number of google hits, I found some interesting data at the DOE site:
ott.doe.gov
ott.doe.gov
The second one interestingly lists higher specs for HEV than EV in terms of specific power and power density; presumably this arises due to the HEV having to carry the added 'dead weight' of the other power plant, etc., in certain propulsion modes? Conversely, the energy density req't for HEV vs EV is lower, presumably due to HEVs not needing to sustain propulsion by purely electric means for long durations.
The cycle life requirement raises interesting questions to my mind. The EV can be assumed to be driven from a completely charged to completely discharged state, and thus only requires 1000 cycles before replacement of the battery. But the HEV suffers under much more extreme cycling, with the listed requirement given as 200,000 cycles of 25 Wh impulse drain (down to 50k cycles of 100 Wh pulses, depending on vehicle size and application). This is where I am completely ignorant as to how the various chemistries behave. Have you any thoughts on this?
OT with an increased dependence on fossil fuels requiring the US to stay involved in politically unstable parts of the world, perhaps we will once again see an impetus towards alternative energy; since the automotive industry has invested much capital in the perfection of internal combustion, it seems a most natural evolution to proceed towards HEV development rather than pure EV; we shall see.
Argonne Nat'l Lab is working on a report comparing costs etc
transportation.anl.gov
Ford is still planning a release in 2003 of a 'mild hybrid' EV version of its new small SUV, the Escape, which uses a 42v ISG system:
prnewswire.com
I noted their comments on the evolutionary development from ISG to fully HEV.
Our Japanese friends are also testing systems:
autoworld.com
Still digging around through my google search, but noting progress. The price hurdle may not be insurmountable.
Best Regards, Rich |
