I was including air drag in the frictional losses, indeed it is their main component, and does go as the square of the velocity (air drag energy loss = work of the drag force = 1/2 * rho * Cx * Frontal area * v^2 * distance), so you may have missed my point, which is that 12 kWh is probably quite enough to run that small van 200 to 300 km at 20 to 30 km/h.
Your 100 km/h figure is their top speed, not the speed for their range test, which as I said can be easily inferred from their "200 to 300 km or 10 hours of driving" spec as between 20 and 30 km/h. Cheers, Michel P.S. I am not particularly negative and have no special information on Negre and his company, I think the technology is very nice actually. ----- Original Message ----- From: "Jones Beene" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Friday, August 01, 2008 5:35 PM Subject: Re: [Vo]:Re: Cost per mile of CAT vs EV (was Re: Doubly disruptive?) > --- Michel Jullian wrote: > >> Note they say "200 to 300 km or 10 hours of >> driving", which indicates a range test speed of only >> 20 or 30 km/h, which is about 4 times less than the >> 100 km/h you have assumed, i.e. assuming friction >> losses going with the square of the velocity the COP >> could be as much as 4^2 = 16 times lower than the >> COP you computed, IOW a COP of 8/16 = 0.5 which is >> much less exciting! > > Ha false logic on several levels. Firstly - frictional > losses are small in comparison to aerodynamic drag - > which is far greater at the 100 km/hr, which in the > end make the conclusion actually far more exciting ! > > Jones > > Anyway, Michel - you are being unaccustomedly negative > in light of the "French Connection" to Negre... or do > you hear rumors that this company may not be on > up-and-up ? > >
