Electric cars major environmental threat!

Post by **Nevilleh** » Mon, 29 Mar 2010, 12:19

See this link:
http://dogandlemon.com/site/2010/03/28/ ... al-threat/

It is very much worth reading. See also the link comparing the Tesla with the Elise.

Post by **coulomb** » Mon, 29 Mar 2010, 16:51

They're quoting an article by Clive Matthew-Wilson. Enough said.

Tesla's batteries are not very efficient huh? Compared to a petrol tank perhaps. But the battery and motor combination are about 6x more efficient than a petrol tank and internal combustion engine combination.

Post by **coulomb** » Mon, 29 Mar 2010, 17:02

See also this post.

Post by **Nevilleh** » Wed, 31 Mar 2010, 16:37

Yes, he writes about many things in his article. I would hesitate to call it a paper.

I note that he gives energy consumption figures for the Tesla as "good" being 230 wh/km. "average" at 330 wh?km and "poor" at 550 wh/km. Talking about driving gently thru to hard. But I have seen people on here claiming around 160 - 170 wh/km for a not very aerodynamic, not very efficient, home made EV. Tesla spent millions on making an efficient, aerodynamic vehicle and I would have expected much better figures than that. Makes me wonder how good his "research" actually is. But he raises a lot of interesting points, all of which are worthy of consideration no matter how flawed his research may be.

He makes NZ look good!

Post by **antiscab** » Wed, 31 Mar 2010, 19:23

the difference is the converter has a tendancy to quote wh/km at the battery, which doesn't take into account charger and battery efficiency.

Manufacturers and those doing good comparisons use wh/km at the power point.

The Tesla battery isn't that efficient due to the refrigerated cooling used, and the complexity of the BMS.

round trip efficiency of the Tesla battery and charger combo is ~70%

the Ni-mh packs of the EV1 and rav4 EV had the same problem (but their round trip efficiency was ~50%)

The home converted setup is both simpler and more efficient (perhaps at the expense of battery service life?)
a large format LiFePO4 battery of that size for that load is ~95% efficient. (3.2v out, 3.35v in, averaged, no coulomb losses)

if you're charger is also 93% efficient (protech, elcon, etc), than round trip is 88%.
if you're charger is ~82% efficient (zivan) than round trip is ~77% efficient.

Matt

Post by **markrmarkr** » Mon, 12 Apr 2010, 21:40

coulomb wrote: See also this post.

Also see this post for more on Clive's foolishness.