For some rough numbers:

Derate operating voltage to 300 V. [That's a typical derating for conventional capacitors. I don't know the manufacturer's recommended derating for this technology.]

1/2C*V^2=~800,000 Joules => 80 kW for 10 seconds per module; three times that if used in series. For stop and go delivery vehicles that's a lot of stored energy from regenerative braking. So what are the cost and physical dimensions?

Maxwells were typically around 7 Wh/kg - so if similar energy densities then each module should weigh in at around 30kg, not including casing etc.

Kinetic energy is 1/2MV^2, so for 5000 kg at 40 mph (17.9 m/s) the energy is about 800,000 J ... or one bank of supercaps at, say, 50 kg including packaging, cooling, mounting, etc. If 50 kg of capacitors can recuperate 800 kJ a million times over its lifetime that's 222 MWHr.

Of course there are efficiency losses along the way, and this assumes the single bank of capacitors can accept energy at a very high rate (80 kW for 10 s). So call it 150 MWHr. Multiply times 100, 000+ delivery vehicles, buses, etc ... now you're talking about some significant energy savings (15,000 GWHr). Assuming 25% efficiency for the diesel engine that equates to about 350 million barrels of oil (at 1718 kWHr/barrel), worth $20B at $55/barrel, and some 280 billion lbs of CO2 (at 800 lbs/barrel).

That's a lot of energy to save, and the weight of the energy storage device isn't that much of a burden. Carrying heavy batteries around adds a lot of weight to a vehicle, which in turn is a big drag on efficiency.

Check my math ... please. And you ME types can also check my efficiency assumptions. This is admittedly a "back of the envelope" estimate.

Its likely the old design of ultracap just bigger and thus higher capcity. The newer ultracaps can store alot more power.

Let me try to disprove this claim of how revolutionary this module is. To do this, I will apply real electrical engineering science:
The energy stored in a capacitor is given by the formula:
E = (1/2)* C * V^2, where C is capacitance in Farads and V is the voltage across the capacitor.

From the manufacturer's data sheet for this module, the capacitance is 17.8 Farads and the max voltage is 390 V, the maximum energy that can be stored is:
E = (1/2) * 17.8 F * (390 V)^2 = 1368900 Joules

1 KW*hr(kilo-watt-hour) = 3,600,000 Joules, therefore this module can store 0.38025 KW*hr.

Now the real problem. From the manufacturer's data sheet, I obtained a mass of 165 Kg for this module, therefore the energy density is about 380.25 W*hr/165 kg = 2.3 W*hr/kg. This is extremely low for any useful energy storage devise for an EV or plug in hybrid.

How about Power density, the real strength of a capacitor? You can have 150 Amps for continuous discharge or 950 Amps for short bursts. This means that the maximum continuous power is about (150 Amp * 390 V)= 58.5 KW and the maximum peak power of (950 * 390V) = 370.5 KW. With a mass of 165 Kg, the continous and peak power density comes out to be about 0.355 KW/Kg and 2.245 KW/Kg respectively.

How does this "revolutionary module" compare with the state of the art lithium ion battery? Well, let's take Altair Nano as the standard.

Energy density = 90 W*hr/Kg (which is very poor when compared with other lithium ion batteries and yet is 39.13 times more energy dense than this capacitor module!)

Continuous Power density = 4000 W/Kg (the Maxwell module peak power density of 2245 W/Kg is lower than the battery continuous power density!)

How about the number of charges/discharges? It turns out that the Altair Nano batterys can be fully charged/discharged for 20,000 times and still retain 85% or nominal capacity. This means that over the life of the battery, a module of 165 Kg of Altair Nano batteries can store and release about:

165Kg * (85%) * 90 (W*hr/Kg)/(charge/discharge) * 20,000 Charge/discharge = 252,450 KW*hr of energy

A mid size electric car can go 4 miles for each KW*hr of energy, therefore an EV with this 165 Kg module of lithium batteries can go up to 1,009,800 miles! This far exceeds the expected milage of any car. In practice, the calendar life of the battery will reduce this number.

Conclusion: Unless there is a quantum leap in both energy density and power density, the Ultra capacitor is dead.

Stan - Thanks for the link. IMO every thinking person should do themselves a favor and view that video. It's quite long (1h13m32s) but well worth the time.

Has anybody compared this to the hydraulic hybrids(yes I know, hydraulic/nitrogen hybrids)that UPS is testing? I believe that was quoted as having a higher wheel to pressure tank to wheel efficiency. They both seemed to be aimed at the same target, heavy duty commercial vehicles that operate in a stop and go driving pattern. Oh well test them both out and see which one comes out on top.

Supercaps are no competitor to batteries, rather complement to adsorb high currents associated with regenerative braking, prolonging battery life. From all batteries Altair Nanosafe is the last to benefit from this combination.

Maxwell supercaps are extensively used in leveling-off surges in wind turbines, as emergency energy storage in smart electricity meters, and as initial (7 seconds) power supply in un-interrupted power supply systems – before diesel generator kicks-in, and many other applications. Also supercaps are considered as the only viable option for heavy-duty hybrid vehicles, like 18-wheelers.

Rafael:

I believe that your estimation is a little bit on pessimistic side: regenerative braking efficiency around 50% is reported for Toyota Prius, heavy-duty supercap systems should perform better. Oshkosh Truck series hybrid military truck eliminates transmission, transfer case, driveshafts, and claims 40% improvement in fuel efficiency:

http://www.oshkoshtruckcorporation.com/about/tech_innovations~propulse.cfm

Stan:

I have read a lot of comments on Swindle documentary, including from some scientists, and the only factual mistake they found is overestimation of CO2 emissions from volcanoes (political staff aside). Everything else is correct. BTW, there is another nice piece, current Congress testimony of President of Czech Republic Vaclav Klaus:

http://republicans.energycommerce.house.gov/108/letters/3.19.07_Vaclav_Klaus_response.pdf

I'm not sure about low cost - particularly when compared to batteries in terms of $ per kWh. Also, the voltage conversion from battery to motor is much easier (read cheaper) than the expensive electronics required to convert the plummeting voltage from a capacitor on discharge.

One regenerative idea was to use compressing nitrogen. You could combine ultra caps with that scheme. Use the caps from above 5 mph and below use the compression, which claimed to be 70% efficient at recovering the energy. Your brake pads would sure last a long time.

@Andrey:

"Supercaps are considered as the only viable option for heavy-duty hybrid vehicles, like 18-wheelers."

Volvo Trucks would presumably beg to differ:

http://www.greencarcongress.com/2006/03/volvo_group_int.html

Basic electrical principles say that a generators voltage is proportional to its speed. As the vehicle slows the voltage goes down as the voltage of the ultracap goes up. Current and therefore braking force is a function of the voltage difference and at some point well before a full stop the voltages will be equal and no braking force will be available. How does this system overcome this problem???