Slashdot Mirror
Ultracapacitor Bus Recharges At Each Stop
TechReviewAl writes "A US company and its Chinese partner are piloting a bus powered by ultracapacitors in Washington DC. Ultracapacitors lack the capacity of regular batteries but are considerably cheaper and can be recharge completely in under a minute. Sinautec Automobile Technologies, based in Arlington, VA, and its Chinese partner, Shanghai Aowei Technology Development Company, have spent the past three years demonstrating the approach with 17 municipal buses on the outskirts of Shanghai. The executive director of Sinautec touts the energy efficiency of this approach: 'Even if you use the dirtiest coal plant on the planet [to charge an ultracapacitor], it generates a third of the carbon dioxide of diesel.'"
the company name says it all!
*ZAP* Aowei!
Oh, first post!
The next model will come with a flux supercapacitor, and will generate several sequels.
Exxon buys them out, or lobbies against the tech and throws campaign money to the folks that make the municipal decisions, as big oil does with everything else progressive that possibly endangers their energy monopoly.
'We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.' RPF
Aren't these, in the end, pretty much the same as a trolley? The bus is really a mini-bus that holds 11 people. It uses 40% as much electricity as a trolley. If you expanded the bus to hold as many people as a trolley can, wouldn't the increase in size and weight (both bus weight and passenger weight) make it use more energy?
If so, then what's the difference between this and, say, a mini-trolley? I mean, hell, why not ultracapacitor golf carts or something?
http://www.tenjou.net/
The cap's are under the seats?! Call me old fashioned (and it won't be the first time) but I'll take a cab, thank you.
people said i was crazy when i talked about this a few years ago. the best advatage of UC's is they don't melt when you discharge a huge current as batteries do, hello electric sports cars that kick the shit out of petrol engines.
If you mod me down, I will become more powerful than you can imagine....
Engineer: Sorry, the idea didn't pan out. The battery works, but it's got no capacity. Useless.
Marketing Guy: What do you mean, no capacity? It can't be zero if it works, right?
Engineer: Sure, but it gets drained in seconds by any sort of circuit.
Marketing Guy: They recharge as fast as they drain, right?
Engineer: Yeah, sure. but...
Marketing Guy: "Recharges in under a minute". Nothing on the market can match it. When can we ship in volume?
Pretty neat. There's tons of other uses for this technology. Among other things, ultra-capacitors are probably the way to go for non plug in hybrids.
Why would you be dead at a red light? If you're not moving then you're motors are drawing power.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
if that cap explodes, i could see it being very very bad.
If the fuel tank explodes...
You can't take the sky from me...
For urban locations where stops are seldom more than a block or two apart this makes for lower infrastructure costs, as no over-street trolly cables are needed.
The ability to alter routes would also be fairly flexible because you could tie into the power grid anywhere you need to add a station.
But the amount of power you need to deliver in a short time means that the stations have to have either the ability to acquire and store a massive charge in the between-bus intervals, (their own ultra-capacitors) or the grid inter-tie would really have to be massive enough to dump that much power into the bus in a couple minutes, for as many buses as you need to send down the line in rush hour.
A shorted capacitor might be fearsome fireworks display.
Sig Battery depleted. Reverting to safe mode.
I imagine the streets of many major cities may wind up getting traffic jams very frequently, so what happens if the bus gets stuck in such a one, and it takes an hour or more to get moving again (e.g. vehicular accident further down), or however long it takes to discharge the ultracapacitors? I suppose it may be necessary to install a backup engine that runs on conventional fuel, possibly just to run a generator which will charge the ultracapacitors sufficiently to get to the next stop.
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
What I think it'd do instead is be like a hybrid that has the ability to recharge at every bus stop.
That's exactly the sort of thing this system does. Each stop has a set of overhead lines that allow the bus to recharge its capacitors enough to get to the next stop.
But then again, what provides the electricity? If it's more fossil fuels, then it's not being green; it's cutting diesel costs.
From the summary: "Even if you use the dirtiest coal plant on the planet [to charge an ultracapacitor], it generates a third of the carbon dioxide of diesel."
We all know what to do, but we don't know how to get re-elected once we have done it
Sinautec, as I suspected, is a Chinese firm, with an office in VA.
http://www.sinautecus.com/contact.html
Remember "News for Nerds, Stuff that Matters"? Help make it a reality again! http://soylentnews.org
Is what makes bus travel POSSIBLE!!!
Science advances one funeral at a time- Max Planck
In soviet russia, ultracapacitor bus recharges YOU!
The ultracapacitors are made of activated carbon and have an energy density of six watt-hours per kilogram. (For comparison, a high-performance lithium-ion battery can achieve 200 watt-hours per kilogram.) Clifford Clare, chief executive of Foton America, says another 60 buses will be delivered early next year with ultracapacitors that supply 10 watt-hours per kilogram.
Or, to put this in more sensible terms. 0.021MJ/kg (0.036MJ/kg next year) for an ultracap vs 0.72MJ/kg for a lithium-ion battery. Aka, the tiny bottom left square in this chart. Compare this to, say, gasoline at 47MJ/kg or even hydrogen at 142MJ/kg and you start to get some idea of why people are excited about "the hydrogen economy".
How we know is more important than what we know.
Last I checked, capacitors have a very long lifespan, many many years compared to what, 5-10 for lead acid and lithium ion. They don't get memory, their performance doesn't degrade over time. And unlike lead acid, they don't mind the vibrations and jolts of being in a vehicle. I'm not aware of any severe temp restrictions on them either - I know for certain that hotter areas of the country have to have different kinds of batteries because of how heat kills batteries. (moreso than cold)
So that makes them cheaper to run since you don't have to change out batteries for many thousands of dollars every 5-7 years like you do on the hybrid cars.
I work for the Department of Redundancy Department.
http://www.utexas.edu/research/cem/Energy%20Storage%20Composite%20Rotor.html
The University of Texas at Austin Center for Electromechanics (UT-CEM) has developed a 2 kW-hr flywheel battery for energy management on a hybrid electric urban bus. The battery will recover braking energy and store excess energy generated by the prime mover. The flywheel rotor, fabricated from high-strength composites, spins at 36,000 rpm at full charge (~825 m/s tip speed), and is housed in a vacuum enclosure to minimize windage drag. A cross-section of the flywheel system design is shown. Ensuring flywheel safety is a major issue that must be addressed in using flywheels for transportation applications. In support of this activity, the durability tests performed under Phase IV of the DARPA Flywheel Safety Program, focused on this flywheel design.
Muchas Gracias, Señor Edward Snowden !
"Even if you use the dirtiest coal plant on the planet [to charge an ultracapacitor], it generates a third of the carbon dioxide of diesel.'"
Petroleum diesel C16H34 or C14H30
Coal Errrrrr C with variable trace quantities of S, H, O and N.
Subcritical fossil fuel power plants can achieve 36–40% efficiency. Supercritical designs have efficiencies in the low to mid 40% range, with new "ultra critical" designs using pressures of 4,400 psi (30 MPa) and dual stage reheat reaching about 48% efficiency.
Ideal diesel efficiency of 56%, but lets stay sane, I keep hearing more along the lines of 35% (Probably BS but real numbers have been banished/obfuscated/hidden somewhere)
Factor in 15% to 50% (extreme) grid transmission loss, and (ops) 5% to 10% electric motor loss.
Love the idea of a Ultra Capacitor for a Hybrid, just stop saying silly things. Less CO2, you're funny.
Ever wired a capacitor in backwards? I have, the result is loud.
Now blowing up a bus might be as easy as cross wiring the charging terminals.
From http://en.wikipedia.org/wiki/Greenhouse_gas:
Fuel name CO2 emitted (lbs/106 Btu)
Fuel oil 161
Coal (bituminous) 205
Coal (subbituminous) 213
Coal (lignite) 215
Coal (anthracite) 227
From http://en.wikipedia.org/wiki/Internal_combustion_engine#Energy_efficiency:
"most engines retain an average efficiency of about 18%-20%"
From http://wiki.answers.com/Q/What_is_the_energy_efficiency_of_an_average_coal_powered_plant:
"According to Hans-Dieter Schilling (Energie-Fakten), the average efficiency of all coal power stations in the world currently stand at around 31%"
Mashing those numbers around a bit I get around 900lbs of CO2 per usable MMBTU from diesel (fuel oil, close enough for these rough numbers), vs 700lbs of CO2 per usable MMBTU from coal based electricity. That's not even 1/3 less, far from the 2/3 less they are claiming.
There are extraction/transmission/conversion losses in both cases that could be factored in, but it's hard to see how it could change their math by a factor of two.
Am I missing something obvious?
For this very reason I hate mandatory seatbelt laws, if there's the possibility someone will burn to death they should have the choice as to whether or not they will wear a seatbelt.
If you don't wear a seatbelt, you may suffer additional injuries that prevent you from escaping a burning car. You will also be worse off in any accident that does not involve a car fire. A much better solution is to wear your damn seatbelt and carry one of these in the car.
In my part of the world at least, you need a lot of power to warm a bus from -40 to something more reasonable. Diesels have a hard time keeping up.
Would they have another bank of capacitors for resistive heating?
What if the bus gets stuck in snow and runs out of charge? will the snow and slush cause problems with the charging contacts?
Trolleybusses seem a lot more practical to me, I never understood why they are so unpopular in north america, even if only used in high density areas, where the infrastructure would pay off.
Sent from my PDP-11
Page 2 of TFA:
http://www.gizmag.com/michelin-active-wheel-production-electric-car-by-2010/10489/
I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
Make the flywheel brittle - like a ceramic or like those shotgun rounds that disintegrate when breaching a door. That way if containment is breached, it turns into powder.
..........FULL STOP.
The solution, found in the 20th century, was the constant velocity joint. Tinfoil hat not needed. They went to Detroit and some old guy in the SAE said "folks, we tried that and it was a very bad idea because..."
Car makers have had over a hundred years of experience of what does, and what doesn't work. They don't suppress technology because it might replace theirs - everybody wants a technology lead. They just don't buy stuff that doesn't work.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."