Everyone who owns a mobile phone knows something about rechargeable batteries, but not that many non-engineers really know about capacitors. Even so, big capacitors - aka supercapacitors or ultracapacitors - have just gone mainstream. It was announced last week that the Honda FCX will be sold to ordinary drivers from 2008. Like …
Darwin award candidates
I can see it now. In the front of the owner's manual for your new Honda, the text: "WARNING: Do not test the charge of your ultracapacitor by shorting it across your tongue".
How many times have we seen new cars or other technologies proposed that are dependent on some breakthrough technology yet we have never before seen the breakthrough technology in mainstream? Total rubbish. Anyone interested in a Flying Car??
As a side note - Why even mention Toyota? Toyota Prius has 10 real years of on road experience. Anyone who has looked into Hybrids has to appreciate the Toyota's Hybrid Synergy Drive which is less about gasoline engine and battery and more about the sun planet gear system which ensures the dead mechanical weight of the gasoline engine crankshaft and pistons are stationary when the vehicle is running on electric power only - Honda cannot even do this.
...is there anything they can't do?
Back to school ?
Even better, if I remember correctly, this means you could charge up your car by rubbing a piece of fur on an amber rod, holding the rod near the car, touching the car briefly then withdrawing the rod.
How green is that !!
Wanna ride my...
750 Gµ motorbike?
Yeah baby! Climb that hill....
<..a seventies-carpet style structure dubbed "electric shag". >
Imagine the carpet burns when you're giving it full poke.
The electric vans with wall to wall electric shag and CB radio are really groovy!
"sun planet gear system"
Like that employed in the Model T, then? Honda's Insight has been around nearly as long as the Prius, so they're not completely new to electric propulsion...
>unlikely ... ultra-ultracapacitors will serve to power cars on their own
Given big enough wires though, you can charge a cap very quickly so couldn't you just "refuel" more at fuel stations which have bloody big wires?
On another note has anyone actually _made_ anything from nanotubes rather than just doing a theoretical simulation of what might happen if you could possibly arrange the nanotubes in maybe this way or that?
I like the idea of "Electric Shag"
Hasn't BMW announced this already?
Wasn't BMW trying trying put Capacitors in door sills?
oh well no news like old news..
The usual problem cited with regular batteries is that they are heavy. So we're going to replace them with vaporware ultracapacitors that at best will store half the energy for the size? Why?
Using large capacitors for transport - DIY
1 - Drag washing machine to kitchen door.
2 - Set for low temperature wash
3 - remove backplate
4 - stick 2 finger on capacitor terminals
5 - wait for back-and-forth cycle to start
6 - fly accross the garden.
If you want really big capacitors
I mean totally humongous ones, big enough to shag a planet, you have to look into space. They're called "double layers". That's right.
How many Farads?
Surely in a story about huge capacitors the actual capacitance of said capacitors could be mentioned, unless you're all too incapacitated to say?
(and what is Paris Hilton's capacity?)
Well, the problem is that the capacitors will need recharged every 45 seconds or so, more if you push the accelerator much. Thats the point of having the H fuel cell on board. As for capacitor vs. batteries, the capacitors can deliver their sotred energy much faster than any battery, thus accel and up-hill performance should be better, at least thats what they hope. I think it sounds like a good enough idea, but the problem is still "How do you power the fuel cell?" Can't exactly carry a tank of H2 around and H2 production/storage is still expensive....
Fuel Cell comercializaton
It sure seems like everyone is extremely cynical about fuel cell vehicles.
It would be a good idea to read current new about fuel cells before dismissing them completely. http://www.fuelcells.org/
The are a lot of fuel cells trials currently being conducted by most automobile manufacturers. Companies like GM, Ford, Chrysler, Toyota and Honda have been running hydrogen fuell cells for several years. There are hydrogen fuel cell cars and buses that have been operational for years. We are only a few years away from fuel cell cars that can be purchased by the public.
methinks they're reaching too far this time
it would make a lot more sense to build a gas electric hybrid and run the ultracap instead of the batteries, give it a few years in the real world, like the Prius. Then later make a change to play around with fuel cells.
What needs to happen is to build a better true hybrid- Absolutely *no* mechanical link between gasoline motor and wheels. Use something similar to AC Propulsion's 300 HP AC electric motor and controller. Run a much smaller IC motor, less than 1 liter. perhaps even direct injection diesel. Homebuilt hybrids were hitting 60 plus MPG years ago made out of recycled aircraft APU systems and leftover parts from forklifts. Purpose built stuff that's not 20 years old, backed by dedicated auto engineering staff, should get similar mileage with much better output and reliability.
Let's get the "hybrid" part correct first, before adding bells and whistles.
But, at least they're not going back to flywheels.
Clue: Capacitors don't power the car all the time
The capacitors are for storing electricity which would otherwise be immediately wasted. When electric vehicles brake, the motor is used as part of the braking mechanism. This means that the motor is running as a generator. The diesel-electric trains currently use huge resistor packs to convert electricity into heat. Instead of wasting that electricity, it can now be used to charge up the ultracapacitors. Then the ultracapacitors are tapped for starting the car instead of the batteries. Two minutes of run-time are more than enough to bring the car up to speed from a stop.
@ Brian Miller
Stop making fucking sense, OK? The "It won't work" brigade are having fun bagging the technology based on half-arsed assumptions and no understanding of current technology.
Stop ruining it all for them by using intelligence.
That goes for you, too, Noah. Fuck sake! Remember: "electric vehicles will not work" - all the petrol companies say so!
Not far-sighted enough!
The criticism of the Prius is that it is only as efficient as a good diesel car. The criticism of lead-acid batteries is that they don't have a high peak power output. The criticism of supercaps is they don't have the energy density of batteries. So, why not:
Have a smallish diesel motor, use it (a la the Prius) to power the wheels when needed and to charge the batteries in a managed fashion (rather than dumping the regeneration load into them say), and use the supercaps to provide that extra bit of oomph for the really sharp power demands. Regenerate into the supercaps. There'd be no real extra complexity than the current Prius except for perhaps a circuit to manage the load between the batteries and the supercaps. And that would probably be less than a dozen components...
Now, if anyone tries to patent this, can someone point this post out as prior art...
But how does it really compare with Lithium, and where do I buy some?
Following links to the Honda site I read: "The output of the nickel hydride battery is around 900W/kg...ultra-capacitor further improves on the performance of the previous model, achieving an output density of 1750W/kg or more." According to Wikipedia Lithium batteries have a Power/weight or 1800 W/kg. I have a set of A123 in a Milwakee power tool pack that I use on a scooter that is 2.2lbs(1kg), is rated at 28v*50A(1400W), but which is capable of delivering 100 Amps, besting the capacitors at 2800W/kg.
On the capacity side of the scale the ultra-capacitors appear to be capable of storing "2Wh/g" (2000Wh/kg?), which is absolutely ridiculous, someone obviously misplaced the decimal point here, perhaps they meant 200Wh/kg? The best I've seen is EEstor with "342 Wh/kg" or "1MJ/kg" (277Wh/kg), though It doesn't sound like these actually exist outside of the lab.
For the record Lithium comes in at about 160 Wh/kg, My power tool pack is about 84Wh/kg. Which is good enough to drive my electric scooter for about 2.5 miles, about 1 mile per Lb of battery, with twice the 50Amps it needs to pull a hill.
I'm all for the improved cycle life of electro static vs electro chemical storage, but I'll need to be able to actually afford to buy one before I'm willing to "Buy" any of the hype. I'm also curious what the self discharge rate of the capacitors is? It's traditionally much higher then chemical batteries.
In the end I'd rather prefer to be able to buy a new Electric, perhaps with a range extending ICE, based on the 10 year old RAV4-EV (which are still running strong on their "inferior" NiMH batteries) than be told to wait just a few more years for a ultra-cap/Hydrogen Fuel Cell car which will cost a half million $, and that requires additional special hardware and a NG (read Fossil Fuel) connection if I want to be able to charge it at home. It seems to me that someone just doesn't want to relinquish the fuel supply chain monopoly.
@ Jon Minhinnick
Quite agree with combining all the technologies to use what's best for the particular task. Also some one above mentioned diesel/electric trains. I have long thought this is worth looking into for cars. Okay so cars tend to do far more start/stop than trains but the thing that gets me about these IC engine/electric combos that work by using the IC engine for going faster/accelerating harder than their electric drive system can manage is that IC engines produce more pollution and have more damage done to them when they're starting up and when they're running cold. A system whereby the IC engine can run at it's most efficient revs all the time generating electricity (perhaps increasing revs when necessary - just stand next to an intercity 125 when it's leaving the station!) I reckon it'll be far more efficient and less polluting than constantly starting and stopping the engine. Has any one researched this?
They're making cars heavier & heavier. The new Mini is heavier than Granada's/Omega's etc... of the 90's. The prius probably weighs something similar to a Rolls with that big battery in it. Good way to cut gases. I'd do more good if I stopped farting.
>the capacitors will need recharged every 45 seconds or so
I thought they were supposed to carry half the charge of an equivalent battery, so half the range?
Unless you mean that battery cars can currently only go for an hour and a half...
Regarding why everyone is so cynical about fuel cells, it's because it's so hard to store hydrogen in meaningful quantities. Its weight/volume ratio at standard pressure is abysmal, when liquefied it will boil off in a few days even in the more heavily insulated container (thus preventing you from keeping your expensive car in an enclosed space), the alternative forms of storage - metal hydrides - at the moment do not compare well with high pressure tanks (that give ~200 km of range and are to all effects a bomb behind your seat)...
For more details, see http://en.wikipedia.org/wiki/Hydrogen_economy#Storage .
There was a good coverage of the technical/economical issues of hydrogen in a 2005 issue of Scientific American, and to my knowledge there haven't been any breakthrough in the meantime.
Had to say it... heading towards the door...
* suddenly, he shouts *
Just want to remind people, how this fuel-cell stuff is hogwash.
* the audience gasps *
Watch: "Who killed the electric car?"!!
Read: "The Hype About Hydrogen: Fact And Fiction In The Race To Save The Climate" (by Joseph J. Romm)!!
* guards approaching *
Don't taser me bro!! Don't taser me!
* The sound of (unchecked) Capitalism killing Democracy ... BZZZZFFT!!!! *
It isn't necessary to carry around a tank of H2 to supply fuel cells.
Energy Conversion Devices sells a converter that will take pretty much any organic fuel and produce gaseous hydrogen and pure carbon (black). Thus gasoline, methane, alcohol etc. can be used to power a hydrogen fuel cell.
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