[LINK] ultracapacitors

steve jenkin sjenkin at canb.auug.org.au
Wed Sep 5 20:02:03 AEST 2007


stephen at melbpc.org.au wrote on 4/9/07 10:44 PM:

Stephen et al,

Nobody talks about how to generate all the electricity needed to replace
petrol.
Following is a calculation:
    If all households substituted an electric car, it would increase
their electricity demand by ~30%.

Q: Can we build that capacity in time? Sustainably? Affordably?

Ex: Hybrid vehicle = 50-55mpg (US gal) = 4.3-4.7 L/100km [highway cycle]

Wikipedia says petrol contains around 34.8 MJ/k (44 MJ/kg.)
<http://en.wikipedia.org/wiki/Gasoline>
And up to 37% efficiency
<http://en.wikipedia.org/wiki/Internal_combustion_engine#Engine_Efficiency>
Add drive-train/generator/battery etc losses of 10% (guess)

or 3.2 kWh/l for a hybrid. and we know the l/100km => 14-16 kW/100km
So 50 kWh would give around a 300km range for a car of the weight and
shape of the hybrid.

BTRE reports:
    10.665M motor cars doing a total of 147,728M km/year or
~14,000km/car/year or around 250km/week
    => which is around that 50 kWh

ABS reports [4102.0 - Australian Social Trends, 2006]
- 7.7M households and a total of 205PJ (57 GWh) of the 253,117 GWh produced
or around 142 kWh/household/week.

Adding another 50 kWh/household/week is ~30% increase in demand over
this 142 kWh.

And for a comparison:
In 2004-05 Australia produced 2,446 PJ of derived energy products
(diagram 17.4). These products included thermal electricity (850 PJ),
automotive gasoline (613 PJ), diesel (495 PJ), aviation turbine fuel
(196 PJ) and coal products (168 PJ) (table 17.13). 


========
Comments on the storage device:

Here are some figures of merit for electrical storage devices:
    - Specific Energy:    Wh/kg [also called Power Density]
    - Energy Density:    Wh/L
    - Cost:                      Wh/$
    - Power Density: Watts or Amps @ nominal voltage [it's power output
until flat]
    - charge cycles and "depth of discharge": count and % [e.g. for
Li-ion 500 cycles & 100%]


CISRO have a great line of ultra-capacitors built around aqueous-carbon
<http://www.cap-xx.com/>
- but they chose to focus on small devices, not power applications.
They have some good resources:
<http://www.cap-xx.com/resources/reviews/pwr-v-enrgy.htm>

And a very good comparison of various technologies:
<http://www.cap-xx.com/resources/reviews/strge_cmprsn.htm>
and battery characteristics:
<http://www.cap-xx.com/resources/reviews/batteries.htm>
or <http://en.wikipedia.org/wiki/Rechargeable_battery#Battery_types>

There's a reasonable comparison of batteries at:
<http://www.batteryuniversity.com/partone-3.htm>
and other materials: <http://everything2.com/index.pl?node=energy%20density>
Specific Energy:
    Lead acid:      25-40 Wh/kg
    Li-ion  :      100-150 Wh/kg
    Cap-XX:            1-5 Wh/kg [but power density is 25-250 times
lead-acid]
    EESU :             346 Wh/Kg


So these units are impressive - especially if their Energy Density and
Cost are competitive.


> The US Patent Number, 7,033,406  <http://www.uspto.gov/patft/index.html>
> seems to be generating much interest for ultracapacitor driven vehicles.
>
> The Age says.. " sounds like a death knell for the internal combustion 
> engine ... meaning, a motorist could plug in a car for five minutes and 
> drive 500 miles" <http://www.theage.com.au/news/breaking-news/texas-
> startup-says-it-has-batteries-beat/2007/09/04/1188783194245.html>
> --
>
> US Patent Number, 7,033,406:
>  
> Electrical-energy-storage unit (EESU) utilizing ceramic and integrated-
> circuit technologies for replacement of electrochemical batteries 
>
> Abstract
>
> <snip> kWh. The total weight of an EESU with this range of electrical energy storage is 
> about 336 pounds. 
> --
>
> Cheers, people
> Stephen Loosley
> Victoria, Australia
> _______________________________________________
> Link mailing list
> Link at mailman.anu.edu.au
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>
>
>   


-- 
Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
PO Box 48, Kippax ACT 2615, AUSTRALIA

sjenkin at canb.auug.org.au http://members.tip.net.au/~sjenkin




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