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500 Miles on a 5-Minute Recharge?
ctroutwi writes "In the wake of rising gasoline costs there have been plenty of alternatives seen on the horizon. Including Hybrids, Biofuels, fuel cells and battery powered all electric cars. CNN has recently posted a story about a company (EEStor) that plans on offering UltraCapacitor storage products. The claim being that you charge the ultracapacitor in 5 minutes, with approximately $9 of electricity and then drive 500 miles."
Hate to see the short that could occur if this car was in the wrong kind of accident.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
I am old enough to remember city streets in places with overhead power lines for this. Its ugly. Why? I get 500 miles on a tank of gas (13.5 gallons and 29 miles to the gallon) so why not just let me pull into a service station, which now takes almost 5 minutes for a full tank, and plug in... charge me $20 for the charge, make the 100% profit ($9 for the elec, $9 profit, 2$ to cover overhead)... I end up better off they end up better off (distribution now done by the existing power lines, no need for trucks) and eventually, when we figure out how to make electricity cleaner (or convert part of of grid to wind or water turbine or whatever) the environment would be better off. Sounds like a win/win/win situtation
I reject your reality
The whole idea behind an ultracapacitor is that it stores significantly more energy than a regular capacitor.
Linky:
http://en.wikipedia.org/wiki/Ultracapacitors
Javascript + Nintendo DSi = DSiCade
what kind of a home has a gasoline pump? i'd imagine there would be special places along the roads that you plug into, just like how it works now.
$9 of electricity is about 100 KWh at national average rates. Passing that in 9 minutes gives you an average rate of 1.2 megawatts. What the hell knid of household has the circuit to handle that?
I would be terrified to even stand near such a fueling station, let alone use one or install it in my home.
Imagine the mortal dread of having your 1.2 megawatt car running low on power during a rainstorm.
For all it's potential energy, at least liquid gasoline is relatively stable and safe. Gasoline car crashes generally only cause explosions in the movies. Unless it's an old Ford Pinto, or a truck being tested on NBC's "Dateline."
Information wants to be anthropomorphized.
It's called a MetroCard. Plenty faster, more energy-efficient, and more convenient than a car, and it only costs $76 a month. And you can actually do stuff on your way to work, like read. Try that next time you're stuck in traffic on the so-called "freeway."
And now, a PSA from David Lynch.
I wish that lawn products such as trimmers and mowers would be based on a capacitor. You figure that they would last a life time. In addition, the ability to charge these in a just a minute (on a 110) would be so easy that many ppl would jump at it. Rather than cars, this is a good entry point market for these.
I prefer the "u" in honour as it seems to be missing these days.
The advantage of electricity remains, even if you are still polluting with your power generation facilities.
It is easier to institute stricter pollution control measures at centralized power generation facilities than it is to implement equivalent levels of pollution control in vehicles all over the country. Even very "dirty" methods of producing such power can always be upgraded over time to be less polluting anyways, or possibly even migrate towards emission free power generation. Also, this migration does not have to be instantaneous either, as an incremental change is often much more economical and practical than a single large change anyways. This sort of upgrading would be completely impractical for individual automobile.
Also, it reduces dependancy on foreign oil.
File under 'M' for 'Manic ranting'
Put a capacitor in your home and charge it up at night. Transfer the power to your car in five minutes from your trickle charge capacitor.
Although this still doesn't address the safety issues.
Current and voltage?
You can figure it out if you're willing to make educated guesses.
Assuming 6.2 cents per kilowatt-hour (price in my state), $9 of power is about 145 kilowatt-hours. This energy is delivered in 5 minutes according to the article. 145 KWh / 5 minutes = 1.74 megawatts AVERAGE charging power.
But that's AVERAGE. Because this is a capacitor (albeit an "ultra" one), it charges in an exponential fashion. The peak charging power during the first few seconds of charging is going to be SIGNIFICANTLY higher than 1.74 megawatts. How MUCH higher depends on the impedance of the charging system.
The real value missing here is capacitance. If we knew that, we could work out peak charging currents for given fixed charging voltages, or vice versa. According to Wiki, the "largest capacitance" of an ultra capacitor is 2.6 kilofarads. Using this as a reasonable but arbitrary number, we can set the total energy equal to CV^2 / 2 and figure out the charge voltage: 633 volts.
Okay, so we have a capacitance of 2.6 kilofarads, a charging voltage of 633 volts, and a charging time of 5 minutes. Further, we have to assume some percentage charge on the capacitor -- it never reaches 100% charge because it charges exponentially, so let's say it charges to 99%. We can use that to figure out the impedance of the charging system using the equation for a charging capacitor: 1-exp(-t/RC)=0.99. Let t = 5 minutes, C = 2.6 kilofarads, and we get a charging impedance (value of R) of 0.06 ohms.
Whoo! Now you can compute the peak charging power (at the very beginning of the charge cycle), which is V^2/R = about 6.5 megawatts. That's 10550 amps. And some of that power is lost as heat in the (very large) wires you'll need to do this -- what fraction of the total is lost as heat is left as an exercise for the reader ;-) But suffice it to say, that heat loss will be at a MAXIMUM when the wire resistance is equal to half the charging impedance, so it implies that the resistance of the wire has to be a lot less than 0.03 ohms.
Feel free to work through it using your own numbers pulled from your own butt, if you want.