[FastMover]

If an all-electric drive system (as opposed to high efficiency hybrids like the Volt really is) is to ever reach the practical, production stage with full consummer acceptance, a few things are still needed:

1> the first requirement is a way to make fast, high current conversions from stored energy to drive system for acceleration, hills and starts - and drive system to stored energy during deceleration, downgrades and braking. The limiting factor for these large energy transfers today are the battery technology, both in current limitations and thermal limits. The most promising way to achive the required enegy transfers is the use of Supercapacitors/Ultracapacitors to handle high current demands and surpluses in conjuction with battery technology for long term energy storage. In this next generation vehicle, the capacitor system would operate as a buffer system for the battery system, and provide a means for current limiting and smoothing long term demand and charge;

2> I beleive that the most promising possibility for the replacement of the ICE in the hybrid is the on-board generation of energy using Hydrogen fuel cell technology. This may seem a little far fetched at first glance, but a catalyst-based technology offers the possibility of the lightest weight fuel loads available for the purpose of electrical generation. The challenges of operating temperature and efficiency are quickly being overcome in current research. Alkaline and Reformed Methanol fuel cells are now reaching operating temperatures that are usable in vehicles with efficiencies that are comparible to internal combustion engines (60% or better), which should yield a tank to wheel efficienby of around 45% (twice that of a conventional diesel passenger car). The second challenge with this technology is a practical method for refulling that is efficient from an energy production point of view. Production of hydrogen is less than 50% efficient in its own right and this low efficiency results in a higher hydrocarbon footprint unless the production facilitites are based on discontinuous sources like solar or wind based power production facilities that are combined with electrolyzers and other advanced storeage systems.

The absolute best result would be systems based on solid-oxide fuel cells. But the high temperatures for recombination and weight and bulk of systems to convert the heat to electical energy, not to mention the saftey aspects of the hot ceramics, make this impractical in the near term.

RFB