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Difference Engine: Volt farce

Dec 8th 2011, 7:15 by N.V. | LOS ANGELES

FOR General Motors, a good deal of the company’s recovery from its brush with bankruptcy is riding on the Chevrolet Volt (Opel or Vauxhall Ampera in Europe), its plug-in hybrid electric vehicle launched a year ago. Not that GM expects the sleek four-seater to be a cash cow. Indeed, the car company loses money on every one it makes. But the $41,000 (before tax breaks) Chevy Volt is a “halo” car designed to show the world what GM is capable of, and to lure customers into dealers’ showrooms—to marvel at the vehicle’s ingenious technology and its fuel economy of 60 miles per gallon (3.9litres/100km)—and then to drive off in one or other of GM’s bread-and-butter models.

So, it is no surprise that GM should bend over backwards to mollify customers concerned by recent news of the Volt’s lithium-ion battery catching fire following crash tests. GM is offering to loan cars to Volt owners worried about their vehicle’s safety while an official investigation is underway and modifications made if deemed necessary. The company has even offered to buy vehicles back from owners who have lost confidence in the technology.

There have not been many takers. As of December 5th, fewer than three dozen owners—out of 6,400 Volts sold to date in North America—had requested loan cars. And only a couple of dozen had asked for their Volts to be bought back. At a suitable price, your correspondent would have welcomed the chance to buy one of those secondhand buy-backs for himself, had they not already been snapped up by employees. Dan Akerson, GM’s chief executive, is believed to have bought one for his wife.

The trouble all started in May, when the National Highway Traffic Safety Administration (NHTSA) carried out a routine 20 mph (32km/h) crash test on a Volt—to simulate a sideways impact with a tree or telegraph pole followed by a rollover. Three weeks after the test, the car’s 16 kilowatt-hour battery pack caught fire in NHTSA’s car park, destroying the vehicle and several others nearby.

Shortly thereafter, both NHTSA and the carmaker repeated the side-impact and rollover test on at least two other cars, all to no effect. However, in subsequent tests—carried out in November by experts from the energy and defence departments as well as GM—the investigators deliberately damaged the battery packs and ruptured their coolant lines. One battery pack behaved normally. Another emitted smoke and sparks hours after it was flipped on its back. And a third exhibited a temporary increase in temperature, but then burst into flames a week later.

GM claims the initial fire in June would never have happened if the NHTSA's engineers had drained the Volt’s battery immediately after the impact. It is odd that they did not. When crash testing a conventional petrol-powered car, the standard procedure is to drain the fuel tank to prevent any chance of fire. It would seem reasonable to do the equivalent with an electric vehicle.

But, then, GM did not adopt a “depowering” protocol for the Volt until after the June fire. Even when it did, it failed to share the procedure with the safety agency until embarking on the November tests. In the wake of the latest findings, GM is now working with the Society of Automotive Engineers, NHTSA and other vehicle manufacturers, as well as fire-fighters, tow-truck operators and salvage crew, to implement an industry-wide standard for handling battery-powered vehicles involved in accidents.

Toyota ran into similar troubles when its Prius hybrid car was introduced over a decade ago. Though the Prius’s battery pack is considerably smaller than the Volt's, fire-fighters and other first-responders had to learn how to disarm the vehicle following an accident—by removing fuses from under the bonnet and pulling a catch beneath the rear storage area to isolate the high-voltage system. Until they had done so, they were warned, they were on no account to take a metal cutter to an overturned Prius to extricate trapped occupants. Lurking beneath the floor was a big orange cable carrying a heavy current that would have fried anyone slicing though it.

The lithium-ion cells used in the Volt’s battery pack have many virtues. They are much lighter and operate at a higher voltage than other rechargeable cells—and can therefore store more energy for a given weight. In addition, they have no “memory effect” (the tendency to accept less and less charge each time they are recharged) and can also hold their charge far longer than, say, the nickel-metal hydride cells used in the Prius. For good reason, all plug-in electric vehicles, including the Nissan Leaf and the forthcoming Ford Focus Electric plus Toyota’s long-awaited plug-in Prius, have embraced lithium-ion chemistry.

But lithium is a highly reactive element. If overcharged, physically damaged or allowed to get too hot, lithium-ion cells can experience thermal “runaway” and even explode—as has happened on numerous occasions with the lithium-ion batteries in laptop computers and mobile phones. Also, if allowed to drain completely, they can short-circuit and make recharging dangerous. For these reasons, all lithium-ion rechargeable batteries contain circuitry that shuts them down when their voltage rises above or falls below a certain level.

To help keep the Volt’s 435lb (197kg) battery pack at the right temperature, GM designed a sophisticated thermal-management system. This is separate from the main radiator system, which cools the range-extending motor-generator (a 1.4-litre petrol engine) and feeds the car’s heater. The battery pack, mounted in a T-shaped steel tray with a plastic cover, runs down the centre of the vehicle.

GM believes the Volt's battery problem was caused by malfunctioning sensors rather than chemical reactions going haywire within the cells themselves. The company is currently developing fixes to make the battery’s control systems sturdier. One proposal is to laminate the electrical circuitry. Another involves beefing up the cooling lines. A third is to reinforce the tray containing the battery modules.

Outsiders note that the lithium-ion pack in the Nissan Leaf—the only other mass-produced electric car currently on sale in the United States—is encased in a rigid steel box rather than a plastic framework. The Leaf has come through its crash-testing programme with flying colours. Interestingly, its battery pack manages without any additional cooling system.

Despite GM’s experience with the ground-breaking EV1 electric vehicle in the 1990s, the company still has much to learn about the public-safety issues associated with powerful batteries. For instance, both GM and NHTSA kept their mouths shut about the Volt’s initial fire for the best part of six months, claiming they needed time to assess the results and to carry out further tests. Others suspect they colluded to protect the Volt’s fragile sales. GM hoped to sell a modest 10,000 Volts in its first year, but will be lucky to achieve even three-quarters of its goal.

In November, when GM finally went public about the Volt’s fire problems, it warned owners, dealers and first-responders of the need to drain the car’s battery pack after a crash. The OnStar communications system onboard every Volt should allow the company to dispatch an engineer to drain a battery anywhere in the country within 48 hours. For its part, NHTSA has now opened a formal safety investigation into the crash-worthiness of the Volt’s battery system. Meanwhile, a congressional committee that oversees NHTSA is to hold hearings early in the new year to find out why it took nearly six months for the matter to be made public, and why the committee was not kept informed.

What is left unsaid in all this is the fact that conventional cars with a tank full of petrol are far greater fire hazards than electric cars will ever be. Some 185,000 vehicles catch fire in America each year, with no fewer than 285 people dying as a consequence. But, then, people have been living with the hazard of petrol for over a century. Irrationally, electric-vehicle fires are perceived as somehow more worrisome simply because they are new.

Readers' comments

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2bits

The danger from fire is gasoline and diesel. Man, just witness some of the fire caused carnage at big pile ups throughout the nation daily. An electric car would be the safest place to be in a big car pileup.

wowlfie

GM will shut down Volt production within 2 years with disappointing sells. It won't make close to the 10,000 it predicted this year and even further from the 100,000 it predicted in 2012 and 2013. That's because it's simply over priced and they are trying to 'grab' that $7500 rebate for themselves by overcharging $7500 for the car.

@bobbleheadguru in reply to wowlfie

The Volt launched nationally in the US on November 1, 2011. That is not even 2.5 months. Is it fair to judge a car on its first 2.5 months of sales?

They are simply priced correctly if you factor in fuel savings. I pay $160/month more for my Chevy Volt in lease... get save $140/month in fuel (even including electricity). It is almost a wash. It is just that more goes to my lease payment and less to Exxon, Shell and BP.

And when gas gets over $4.00/gallon after the election, I will come out ahead.

2bits in reply to @bobbleheadguru

I'm the one that comes out ahead. I own a leaf and charge it with free electricity from my solar power panels. I drive free forever and pollute zero forever. That's is what everyone should be striving for. It cost me very little (zero down) to lease the solar power panels which provides 60% of my electrical needs and once I replace the Central AC with a swamp cooler it provides 100% of my electrical needs. Every American homeowner should strive to do the same via leased solar power panels and a Leaf, Fit EV, Ford Focus EV, Rav4 EV, etc.
And if my batteries begin to weaker to 75 to 80% capacity after 8 to 10 years--I simply convert that battery to a full house 'Leaf to home' converter and power my house every night from the stored solar power from the sun daily. Those devices will be on the market this March. Read this: http://www.plugincars.com/nissans-leaf-home-system-could-power-house-two...
Many feel range is too short but 80% full power in 30 minutes at rapid charge stations takes care of most of the problems and withing 3 to 5 years batteries with 1000 mile range, and even 3000 mile coast-to-coast range will be coming out.
At that time everyone has NO excuse but to go electric.

wowlfie

Not so. I for one have solar energy panels carrying 75% of the load and during the day they feed excess energy to the grid (rebates). So during the day I charge the Leaf and drive at night. Eventually I will buy a 2nd one and charge one while driving the other one. So screw the entire oil industry and coal industry and nuclear industry. We don't need any of them if we actively pursued the benefits of solar and stored solar power in molten salts for use at night. It's all about greed not about functionality.

farfrom

I was taught chemistry by a nineteenth century chemist.

Hr said that when cars were being introduced , chemists thought that gasoline was a dangerous explosive substance , and that the idea of the general public handling it was ridiculous

wowlfie

I think the greater concern is electrocution in the event a car is smashed during a rainstorm. The volts used are high (>200) and amperage is easily enough to kill if a person is short circuited between the ground and the battery. The risk if you end up in a stream or river or lake is even greater of electrocution. Even emergency responders are at high risk. I certainly wouldn't want to be in a multi car pileup involving 25 electric cars that's for sure! Something to think about as we get more and more into the eventual transfer that will take place to electrics and alternate fuels.

MRC06405

Let's here it for the economist. This non-story became a story only because other journalist chose to ignore the facts to make the whole silly episode sound more exciting.

The moral to the story is; "If you crash your Volt don't sit in it for two weeks or it might catch on fire." Big Whoop!!

cyclingscholar

In the movie "Babes in Toyland," there is a great final scene where Hardy aims a cannon full of darts at the departing bogey men, only to have it turn on himself. So it is with the Volt. The same environmental extremists who hyperventilate over any safety issue with oil, natural gas, fracking, or nuclear power now will see the regulatory monster turn on them. I suggest we buy Dan Rather a complementary Volt and give him sixty minutes....he should have it in flames in no time!

Michael Dunne

Nice details. These points made it worth hitting the recommend button:

"What is left unsaid in all this is the fact that conventional cars with a tank full of petrol are far greater fire hazards than electric cars will ever be. Some 185,000 vehicles catch fire in America each year, with no fewer than 285 people dying as a consequence."

Dr G Rein

There is a recent technical report from the Fire Protection Research Foundation on the topic:

"Lithium-Ion Batteries Hazard and Use Assessment"
http://www.nfpa.org/assets/files/pdf/research/rflithiumionbatterieshazar...

Geeky note: Semenov's theory expresses that thermal runaway of a reactive system (like a lithium-ion batteri, coal dust or hay bale, to name a few) takes place when the rate of heat generation by the reaction is larger than the heat losses to the enviroment. More at
http://garfield.chem.elte.hu/Combustion/tutorial/semenov/possibilities.html

ZivBnd

This article points out the illogical aspects of the Volt fire controversy. The US needs to reduce its trade imbalance and cars like the Volt, the Ford Focus Electric and the Leaf are the best ways we have to do that, for now. But the price has to come down, and the only way to do that is for the economies of scale to kick in and allow the car makers to build them for less. But even at the current $33.5k net price, the Volt will give a buyer a great deal, since it is near luxury in quality, fit and finish, plus you can go 40 miles on about $1.20 worth of electricity here in northern Virginia. The same distance costs around $7 in a normal, 20 mpg car. Saving more than $150 on gas costs will add up quickly.

leptoquark

"There have not been many takers"

That's probably because they understand that they are in no danger. I agree that this whole business is a farce, in that there's nothing wrong with the Volt. It won't hurt for GM to codify a depowering protocol, but this whole thing was started when the engineers punctured a fully powered battery pack and let it sit.

Unfortunately, when the EV naysayers see the words "Volt" and "fire" in the same sentence, they roll their eyes let their fertile imaginations run.

Can't they see that the only way for the US to use less oil is to use less oil? The Volt, Leaf and other ev's and plug-in hybrids must only be the beginning.

Jintelo

First no power plants use oil, its natural gas, and thay're still good becouse the reduce foreghn petrolium consumption in favor of domestic coal and natural gas, and reduce smog by concentrating diffuse road pollution at a single point plants, and the electricity to oporate them coasts 70 cents a gallon.

Ah Beng in reply to Jintelo

Really, no power plants use oil? On what planet have you been living? I work within a dozen miles of a fuel oil power plant, which burns atmospheric gas oil, a cut of crude.

If you think that electric cars emit by proxy exactly the same amount of pollution as road vehicles do, I've got bad news for you. A hint: the efficiency numbers from heat to the work that moves your car look a whole lot worse if you take into account transmission, charging your battery, and changing that electricity into work.

I'd also like to point out that while point source concentration of pollution may reduce smog, it doesn't reduce pollution. So great, no smog, but everyone downstream of the coal plant still has to repaint every three years.

Wiggers42 in reply to Jintelo

Energy production from fossil fuels has doubled worldwide since 1980. OK so a proportion of this is natural gas, but my basic point stands. Also, several developed countries have severely underinvested in replacing aging power plants and forecast a struggle to keep the lights on towards the end of the decade. Simultaneously there's this mad rush towards electric cars!

Mr. Beng,

The Amazing Chevy Volt EREV....What transmission ?

Off peak power..."Our greatest natural resource"

The FEAR of to many electric cars (EV's) crashing the grid is unfounded, not possible and senseless. The Amount of untapped and unused Electricial power available off peak is astounding!!

"A conservative estimate is that we have an amount of electricity unused at night that’s equal to the output of 65 to 70 nuclear power plants between 6 p.m. and 6 a.m.," Senator Lamar Alexander (R-Tenn) stated before the Senate Energy and National Resources Committee. “I suspect that’s probably our greatest unused resource in the United States. If we were to use that to plug in cars and trucks at night, we could electrify 43 percent of our cars and trucks without building one new power plant.”

http://www.torquenews.com/397/senator-alexander-unused-electricity-our-g...

The Amazing Chevy Volt EREV-Facts Guy

gm-volt.com/forum/showthread.php?9525-The-Volt-White-Paper

Reloaded: December 8th 2011

RSJdBkxZQD in reply to Ah Beng

Hint to Ah Beng: Efficiency numbers already take into account transmission losses etc. The search phrase you're looking for is "well to wheel efficiency" -- you'll find that electric vehicles make better use of energy than those with gas engines. Moreover, that's not the only dimension of the issue. One of the principle goals of the Volt and electric vehicles is to *use less oil*. This isn't just an environmental issue, it's economic. Instead of sending billions of dollars overseas (often to countries we don't like very much) to buy oil, the money stays in the US. And to preempt the tedious retort, no, drilling in ANWAR etc. isn't an answer, reserves would only last a few years. Which brings us on to another dimension: security. Electric vehicles reduce the country's reliance on foreign countries the we don't like very much, and perhaps more importantly that don't like us very much.
As for pollution: First, a point source does allow for a reduction in pollution. Because it is more efficient, less pollution is generated per mile driven. Moreover, it is easier to scrub the pollution generated by a single power station than it is by thousands of individual vehicles. Finally for now, as cleaner sources of energy are brought on line, the overall pollution created is reduced -- something that's not possible with gas engines.

Ah Beng in reply to RSJdBkxZQD

It's ANWR, and I'm as against it as you are. Look pal, you've misread my comment. I'm not claiming that EVs are bad, merely that we need to face reality here. EVs are less efficient, on a burning stuff-to-motion basis, than internal combustion engine cars. They can be more price efficient because of grid pricing fluctuations, and they can be more "green" depending on your local power supply situation. But that's not the same thing as efficiency.

Let's run a little exercise: A modern combined cycle natural gas plant is going to run at around 45% efficiency from gas to electricity. A rule-of-thumb figure for transmission efficiency, including stepping the voltage up and down, is 90%. For charging, we can expect 95% efficiency, also a rule of thumb. Finally, an electric motor can be expected to convert electricity to work at about a 90% rate as well. The overall efficiency is therefore around 35%, give or take a few cents. This represents the best case, because most power plants are considerably less advanced.

The typical V6 internal combustion engine is converting a fossil fuel into work at around 42% efficiency.

If you want to talk about well-to-wheel efficiency, then let's extend the exercise there. The EROEI of a marginal source of gasoline can be charitably said to be around 6 (tight oil or tar sands), meaning that it's around 83% efficient in terms of absolute energy expended in extraction versus what you get out. Strictly speaking, that might include several different forms, but whatever. It's an exercise. A gulf oil rig's crude will get you an EROEI of maybe 20, which will give you 95% efficiency.

The EROEI of shale gas has been estimated at around 70-90, which essentially means that it's close to 100% efficient (i.e. 69/70 or 89/90).

So in the worst case, using the most marginal energy source, an internal combustion engine will net around 0.83*0.42 = 34%. And a good case efficiency for an EV is about the same, which goes to support my earlier point: no change in emissions from EVs. The numbers don't add up.

Number sources: Tester, Drake, Driscoll and Golay, "Sustainable Energy: Choosing Among Options"; The Oil Drum (http://www.theoildrum.com/)

LexHumana in reply to Ah Beng

The commenters are missing the real issue with electric cars. It has nothing to do with disputes over efficiency. It has everything to do with the upfront cost of the vehicles, plus the challenges in "refueling" while on the go.

The 2012 Chevrolet Volt's Manufacturer's Suggested Retail Price (MSRP) starts around $40,000 and loading one with leather, navigation, Bose audio, and the rearview camera and park-assist package will bump that figure to just under $46,000. Even when you factor in the potential $7,500 federal tax credit, this is an extraordinarily expensive for a car that is supposed to be an upscale sedan. Fully loaded, it is equivalent to a BMW 3 series or Audi A4, but those cars start about $10K cheaper.

Doing the math, assuming an average of 30 miles/gallon, at $2 extra per gallon versus the Volt, and averaging 12,000 miles per year, it would take nearly a year and 3 months to recoup the extra premium you pay for the car, before you start "saving" money. If there is no federal tax credit, it would be over two years. For many, it is simply not worth the additional up front expense to get this car.

The Volt at least has the benefit of packing its own recharging generator on board, so in a pinch you can gas and go. But a pure EV has a serious logistical problem -- there are precious few places to recharge, and certainly challenges in speedy charging (unlike a gas car, you can't pull into a station, refuel completely in 3 minutes, and go). The limited range is also a problem. Last winter, there was a major breakdown on I-83 in Baltimore, and cars were stranded on the highway in the middle of a blizzard for over 12 hours. A Nissan Leaf would have died on the highway after only a couple of hours trying to keep its heater running that long, with no way to recharge.

The upfront cost, plus the inconveniences, mean that EVs are consigned to be the 2nd car or toy of those who can afford such playthings. Until that dynamic changes, the argument over what is more efficient doesn't really matter.

Hal W. in reply to Jintelo

Dear J.: The only excuse for such poor grammar, spelling, etc. in your letter
is that you're a foreigner. If not,
then I recommend returning to school for basic writing literacy.
You may have made some good points,
but the grammar was incoherent.

can kurtulus in reply to Ah Beng

Mr. Beng,

An internal combustion engine in real world driving situations would deliver an average efficiency of around 15%. Figures quoted for ICEs that are above 25-30% are simply peak efficiency figures for a very limited operating region (in terms of load and speed) that is only valid for a very small percentage of total real world driving. The problem with the adoption of EVs is not efficiency, but current cost levels and lack of widespread charging stations as some others readers also pointed out.

Ah Beng in reply to can kurtulus

I agree that the problem is always going to be the cost differential versus the savings, at least for the consumer.

However, it is still unfair to account for the idling or stop-go motion of an internal combustion engine and claim it has a lower efficiency without breaking the identical ideal abstraction applied to electric vehicles. For example, you'd be very surprised to note how much the effective range of an electric vehicle goes down once you decide to run the air conditioner.

We could slog out the details one by one, but at that point the whole point of a high-level overview is lost and the "efficiency" figures we derive are no longer comparable with anything but other gasoline vehicles or EVs, respectively.

Wiggers42

The final paragraph is an exact analogue of the irrational fears over nuclear energy. People have been killed in coal mines and oil fields for generations. But if someone gets a bit of a sunburn from a nuclear power station then it's back to the dark ages! And I wonder where all the energy to recharge these new-fangled electric cars is coming from? Oh yes, coal and oil on the whole.

hey_ghis in reply to Wiggers42

When you think of it nuclear energy and electric cars are an very interesting couple.

Uranium comes from abroad but it reveals its potential in home-based factories that concentrate, enrich and transform it in proper rods to fuel home-based nuclear power stations. Then all wastes are encompass in caskets that you can safely control. No air pollution, only warming a bit the air and/or the water.

We tend to forget how badly coal can worsen our health. Uranium concentrate power at an incredible scale (1 gram of uranium produces as much as 1 tonne of oil, so it's a million ration between the two).

8shark in reply to volt11

Did you take into account that it takes at least 6kwh of energy to refine ONE Gallon of gas, and probably another 2 kwh of energy to drill, transport, and pump that gas into your ICE cars tank. (quote from the DOE)

That means your average ICE car uses nearly as much energy to get the gas to you as the Volt uses to drive 40 miles.

Mr. Wiggers42,

Please allow Senator Lemar Axexander ( R ), Kentucky answer your question:

The FEAR of to many electric cars (EV's) crashing the grid is unfounded, not possible and senseless. The Amount of untapped and unused Electricial power available off peak is astounding!!

"A conservative estimate is that we have an amount of electricity unused at night that’s equal to the output of 65 to 70 nuclear power plants between 6 p.m. and 6 a.m.," Senator Lamar Alexander (R-Tenn) stated before the Senate Energy and National Resources Committee. “I suspect that’s probably our greatest unused resource in the United States. If we were to use that to plug in cars and trucks at night, we could electrify 43 percent of our cars and trucks without building one new power plant.”

http://www.torquenews.com/397/senator-alexander-unused-electricity-our-g...

gm-volt.com/forum/showthread.php?9525-The-Volt-White-Paper

Reloaded: December 8th 2011

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