Why can't they make things that we really need, like a traffic light that doesn't change when somebody makes a right turn on red.

"reserve some stored energy against driver demand in excess of available engine power" But that seems to require the 4th cylinder to be retained to provide reserve energy to the KERS. Also, reserve energy with KERS implies that the spin rpm is low. It might be ok for the glide phase, but to get some torque for acceleration, the CVT would have to go into ultra-low gear (under-drive). It needs a change in flywheel rpm to get torque from KERS, if the flywheel's already rotating slowly, the load would deplete the its reserve energy rapidly.

"Presumably, the engine. If the KERS can store enough energy, operational strategy might reserve some stored energy against driver demand in excess of available engine power... at least until it's depleted." But the idea was to make the motor smaller and depend on the KERS to provide power and torque during acceleration. How are you going to get power and torque from the tiny three cylinder, when there's nothing available from the KERS?

I'm with DaveD. If I was a mechanical engineer, especially one working for Volvo, I would love to promote the KERS power/glide. But since I'm an EE, I like the simplicity (no moving parts) of a BEV. Even if the KERS system has the potential to replace the battery system in a hybrid like a Prius, it is complex and I find it hard to believe it will only cost $750-1000 to the consumer, as Volvo says.

What I meant was that the volvo says 25%, but offers no direct evidence, and only claims it's a potential improvement anyway. Roger actually said 20 mph at 4-5 minutes, but I think this doesn't reflect the real way people drive. KERS may work for F1 cars, where plenty of money is available. But the diagrams show very complex mechanical assemblies. How can you put something like that in a consumer vehicle for less than $5,000? Do 60,000 rpm CVTs really exist?

"Cycling an engine off and on at 20-30 second intervals might take some getting used to, but isn't a technical issue." I know cars need little hp at constant speeds, but the stop-start systems currently are only practical for saving idling energy, when the vehicle isn't moving. Driving a stop-start engine seems impractical to me. So you switch off the engine and let the flywheel inertia release energy to the axle for 20 seconds on a declining power band. This would have to be done through a 64,000 rpm CVT to get some torque. Otherwise, the car is going to slow down because the flywheel is mechanically coupled to the axle. When the KERS maximum available power output gets down to 5-6 hp on a level surface and the car starts to decelerate, or when the car starts going uphill, the driver steps on the pedal and to start up the ICE because he needs some torque. On a level surface, maybe the driver just waits until the ICE starts automatically. But it has to spin up the KERS flywheel, which consumes half the power of the ICE until it's up to 60,000 rpm. So this brings up the problem of acceleration while the flywheel is dead. Where does the power come from if the driver needs to accelerate with 100 hp and the available KERS output is zero? I don't believe the 25% number is more than the stated potential increase (is this only at 20 mph?). It seems to me that KERS was developed to improve acceleration, not mileage. The system seems too expensive and complex for a passenger car. Who drives at 20mph for 5-6 minutes anyway?

Of course a car only needs about five or ten hp to maintain speed, so you'd have to start and stop the motor about once each minute, which also seems absurd. Even if it would work, the energy savings would be small. Then you have the dual-drivetrain, like in a hybrid, which makes the car expensive.

"that the flywheel technology combined with a four-cylinder turbo engine has the potential to reduce fuel consumption by up to 25% compared with a six-cylinder turbo engine " There are a lot of assumptions here. Nevertheless, the flywheel only works when breaking. So on long trips there will be no reduction in fuel consumption. To Roger Pham - your power-and-glide idea sounds like free energy. These tiny flywheels store very little energy, only enough for 80 hp for 6 seconds. You can't get a constant 80 hp output anyway, because the flywheels start slowing down the instant a load is put on them. Shutting down and restarting the motor every 6 seconds is absurd.

EV-1 wasn't for sale, so why talk about the price? It was expensive because GM only made a handful. The price had no effect on the EV-1's 6 mile/kwh. It used lead acid batteries and weighed 3000 lbs. Leaf weighs only 10% more, but gets barely 3 miles/kwh.

I would like to know why modern BEVs only get 4 miles/kwh, when the EV-1 got 6 miles/kwh.

Notice that they give the power and energy densities in units of area and thickness - mW cm-2 µm-1 and mW h cm-2 mm-1, instead of W/kg or Wh/kg, like for BEV batteries. This is because the applications for microbatteries are intended for very small devices, specifically chips and tiny circuit boards, where "real estate" is at a premium. Applications for microbatteries like this to traction motors in BEVs is not likely, which should be obvious from this article and the one Kelly found. The 3D fabrication process may be simple compared to that of microcircuit chips, but it's not compared with one for a practical BEV battery. I'd put my money on Rice's Vanadium Graphene battery for BEVs.

"The electrodes are a thin layer of nickel–tin (anode) or lithiated manganese oxide (LMO) (cathode) conformally coated onto interdigitated highly porous metallic scaffolds. " This implies something like a photolithographic process in a clean room environment. The conformal coating and interdigitated scaffolds requires additional expensive processing. A battery suitable for a car might require hundreds of layers of 3D substrates. It would be very expensive for a BEV battery, but practical on a miroelectronic chip as a power source.

Sure, it can get the car moving. But for how long? "The architecture allows compact integration of the anode and cathode on a single substrate for microelectronics applications. The batteries could be further improved by taller 3D electrodes, which would require improvements in the fabrication process." This kind of microchip-style fabrication is expensive.

this doesn't seem like a battery technology for cars. They say the energy density can be scaled up. But how much? The chart seems to show the highest "scaled up" energy density is equivalent to Ni-Zn, which is only 100 Wh/kg, much smaller than Envia Systems or CalBattery batteries at 4-500 Wh/kg. The microbattery architecture seems expensive to manufacture. It might be fine for microelectronic applications.

http://green.autoblog.com/2013/03/29/gm-build-electric-car-korea/ This article that Kelly found says that the GM BEV will use LG Chem batteries. They have licensed the Argonne cathodes and likely will license the Envia Systems 400 Wh/kg battery or their Si composite anodes. It would be easy to get 200 mile range from the Evia battery.

The EV Spark battery doesn't have high capacity. It uses a A123 iron nanophosphate battery, probably ANR26650. It only has about 110 Wh/kg, but it charges and discharges very fast, so it will work with regenerative braking and quick charge stations. It has a long cycle life too. if its range is over 100 miles, it's because it's only the size of a golf cart.

@As Aha CalBattery and Envia Systems both are licensed to use the Argonne Labs developed cathode in their batteries. That cathode has 250-300 mAh/g much better than most cathodes on the market. Their batteries give 400-525 Wh/kg. Rice University announced two weeks ago that they are using Vanadium and graphene ribbons in their cathode to get 425 mAh/g, with long life and high current at the same time. A battery with their cathode and si-graphene anodes may get 700 Wh/kg.

Envia Systems and CalBattery already have Si-carbon and Si-graphene anodes out there. 2020 is a ridiculous goal considering their recent developments.

"lithium polymer" ?

These researchers are not the first to show high current and energy capacity, with long cycle life in V2O2-graphene cathodes. It was independently accomplished a year ago by this research team - http://pubs.rsc.org/en/Content/ArticleLanding/2012/EE/C2EE22004K# They show a 100,000 cycle lifetime.

I would like to see the performance in a Graphene ribbon composite.

I'd love to see the Formula E cars on tracks. The Drayson car looks very hot. But why does it have wireless charging? It seems like in a pit stop, they would just swap the battery. It seems like that would be a lot faster than charging it. I love the videos on youtube of Killacycle and all the other electric vehicles. Some of them accelerate so fast I wonder why we keep talking about ultra-capacitors anymore. Thanks for your comment on my ideas DaveD. I used to be an electrical engineer, but now a software developer. I've been interested in BEVs for about thirty years. Wish I had time to build one myself.

I think it's shocking. When you consider that gasoline has about 13,000 Wh/kg. But, when used in a ICE, which is only about 20% efficient, you get 13,000 x .2 = 2,600 Wh/kg. The BEV would be around 90% efficient, so at 700 Wh/kg, the net result is about 25% of the energy as gasoline for the same weight, which is very significant. I also think the formula 1 car would be practical with such a battery. But you don't need the Formula 1 to get all that torque, you could just use an old Datsun 1200 like this one - http://www.youtube.com/watch?v=369h-SEBXd8

Spelled it wrong twice - graphene, not grapheme. Anyway, it's really phenomenal how important this material has become. Rice researchers are using it in the cathode and likely will use it in the anode when they make their own battery.

It's just absurd when I read something like "Another dream that will never happen" Scientific progress keeps on marching. Only a few years ago silicon nanowires and grapheme were first being tested for use in batteries. Now the silicon and grapheme composites work in real batteries. The Argonne Labs cathode has been very successful in the last few years. Envia Systems announced they were sampling their 400 Wh/kg battery early last year, but now CalBattery is sampling their 525 Wh/kg battery. With a different company making a 25% improvement every year, how does anything actually get to the market before it becomes obsolete?