[LINK] Electric vehicles and generation

[rchirgwin at ozemail.com.au]

Antony Barry wrote:

>
> On 22/07/2006, at 8:33 PM, Kim Holburn wrote:
>
>>  Electric Cars and Their Discontents
>> http://backslash.slashdot.org/article.pl?sid=06/07/21/174214
>
>
>
> What made the most sense was the comment that there is no way you are  
> going to get high power and range. Batteries are suitable for short  
> range vehicles. The best thing on this was http:// 
> hardware.slashdot.org/comments.pl?cid=15749244&sid=191653&tid=232  
> which involved a vehicle with a 100cc diesel motor which was used for  
> battery recharging rather than propulsion.
>
> I have an electric bicycle with a 200 watt motor. I can cruise  
> comfortably with little effort at 25kmph for  a hour before I need a  
> recharge. You can do a lot with a small amount of power. The throttle  
> is linked to the pedals so the harder I pedal the harder the motor  
> works.

Tony,

Power and range are eventually going to run into physics. If you assume 
a drive train that operates at 100% efficiency (as a thought 
experiment), then range is limited by batteries; how much they store and 
how many you can carry. The car's claim is "up to 250 miles" per charge; 
ok. So with 100% efficiency instead of 90%, we get a maximum 440km on 
the charge. More range means carrying more batteries, eventually.

The limit is ultimately how far a body X kg can travel using Y kW of 
power, how much you can carry in the batteries, and electricity 
distribution practicalities (how many houses can be fitted with 70-amp 
circuits).

RC