GM-VOLT : Chevy Volt Electric Car Site

With all of GMs recent trouble coming from the crashing SUV market, they must be looking forward to the launching of their fuel efficient smaller SUVs. The Saturn VUE is on the verge of morphing into first a strong 2-mode hybrid form launching later this year, and after that a lithium-ion plug-in 2-mode hybrid version. The latter has the potential to be the first mass-produced plug-in hybrid to hit the U.S. market.

The 2-mode VUE is expected to get greater than 50% combined improved fuel efficiency .  The plug-in version has the potential for 70 mpg although I have no official figure from GM.  The plug-in VUE is a parallel rather than series design, and although capable of going up to 10 miles pure EV, on-board controllers will choose from the ICE, or a low speed or high speed electric motor, depending on what is best for the driving conditions of that moment.

I had the chance recently to ask GM’s director of hybrid integration, Mick Bly, some questions about these programs.

How is the 2-mode plug-in VUE program coming along?
We have developmental mules up and running on the plug-in VUE. As we announced we have joined in to two developmental contracts with two suppliers, one being JCS and the other being Cobasys/A123 and we are continuing to work with them. We have a lot of good data over the last year. Bench, lab, supplier, and vehicle data and we’re going to continue to work and decide which path we’re going to take in that particular vehicle program.

Are you pitting the two suppliers against one another with the idea that one will be chosen in the end?
No, what we’ve said is that we are going to develop with two suppliers, and we are probably going to look at others also, and we will make a selection on the best solution for the vehicle and then have one put forward into production, very similar to what were doing for the Volt.

Is that program further along than the Volt at this point?
Yes and no. Its further along in the sense that its getting all the benefits of a vehicle that exists, the VUE. Its further along because the 2-mode front wheel drive program is getting very close to production. That takes a lot of stress off my organization to really focus in on converting over to the lithium-ion plug-in system, the charger, the electronics, and the software unique to that. So yes its much farther in that sense but it still has a lot of integration activity left around the battery itself.

When is the target production for the VUE 2-mode?
The VUE 2-mode will be later this year, 2008. The plug-in as early as 2010.

Besides the fact that its not soon enough, the closest date I can get as to this year’s 2-mode VUE release is “a few months down the road” per a GM spokesperson involved in the launch.

An article was recently published in the Sacramento Bee discussing plug-in hybrids. The story emphasized the development of the AFS Trinity which is a plug-in Saturn VUE conversion using lithium-ion batteries and ultracaps which has a 40 mile EV range and range extender.

In a provocative assertion, the author references a UC Davis study noting:
“The 300-pound battery pack General Motors is building into its Chevrolet Volt plug-in, for instance, can’t yet deliver its promised 40-mile range and the long-term durability needed for a mass-market car, according to a report by a hybrid technology research team at the University of California, Davis.”

The article’s author, Jim Downing, was kind enough to give me the reference to which he refers. You can read its 29 pages of technical detail here.

The thrust of the report is to explain the current state of hybrid car batteries, looking at li-ion and NiMh and comparing each, including the various cathode subtypes. They are measured against the required standards set for by among other authorities, the USABC, a government group including representatives from the major US auto makers.

The USABC battery requirements are set forth for a mass-produced PHEV-40 or Volt:

1. Power density of 380 W/kg
2. Energy density 140 Wh/kg (EPRI gives 60 Wh/kg, MIT 100)
3. Energy capacity 17 kwh
4. OEM cost $200/kwh
5. Deep Discharge Cycle 5000

Let’s look at some speculative values our friend Alex S. (AES) has determined for the Volt’s competitive battery-makers.

A123:
Energy density = 108 Wh/kg
Power density = >3000 W/kg

LG Chem:
energy density = 95 Wh/kg
power density = 2000 W/kg

Of course these values for LG and A123 cells are speculative and we do know that new formulations from each supplier have been developed for the Volt project. Furthermore, the cost these companies plan to charge GM for the batteries remains unknown. Most experts quote this presently at $800 – $1000 per kwh. So the price of the Volt then seems to depend in great part on how much GM will have to pay for its battery.

Should GM subsidize the battery-makers or should the battery-makers subsidize GM?

In the end it is fair to say that based on what we know publicly GMs suppliers lithium batteries do nearly meet or exceed meet the USABCs performance criteria, and exceed EPRIs requirements.

Of course all that really matters is that the batteries meet GMs own internal criteria, and the fact is, we already know the first running Volt prototype has met its 40 mile mark.

Source (Sacremento Bee)

California is the only state that has authority to make its own rules about vehicle emissions requirements exceeding federal standards, stemming from its smog problem in the early 70s.

Thursday the California Air Resources Board (CARB) voted to reduce the requirement of zero-emission vehicles (ZEVs) from the initial mandate of 25,000 sales to 7,500 sales in the years 2012-2014. They also must sell 58,000 plug-in hybrids in the same period. The obligation will be spread among the automakers based on their individual market share.

GM representative David Barthmuss was quoted as saying GM is “still scratching our heads” over the implications of this decision, but said the Volt would be sold in large numbers in California due to the mandate. There is additional credit to manufacturers for making plug-in cars.

Also of interest, 12 other states have adopted California’s standards. These include Connecticut, Maine, Maryland, Massachusetts, New Mexico, New York, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont and Washington. 120,000 plug-in hybrids must be sold in in those states by 2014.

Sources (Detroit News) (New York Times) (AP)

One of our readers pointed out an ad the other day in the April edition of Motor Trend in which the Saturn VUE plug-in, slated for production in 2010 is described as having a 34 mile all-electric range. That news certainly got that reader excited, and potentially many others.

This information although exiting did not match with what the vehicle’s chief engineer Bob Reuter told me in Detroit. There he noted the car could go 10 miles all electric, but that it was a blended 2-mode hybrid design, and would only intermittently run on EV only, lending overall to a roughly 50% improvement in mpg over the current VUE XR line. This is not an E-REV, it is a 2-mode hybrid with a large plug-in electric battery.

Seeking clarification from GM on the ad, spokesman Brain Corbett advised me of the following:

“We’ve officially said more than 10 miles.”

and

“The writer mistakenly used the figure for the all-electric range of the Flextreme concept that was introduced along side of the plug-in Vue.”

For a while, GM and Toyota have publicly argued that each PHEV architecture is superior over the other, comparing the Volt (an E-REV) to the prototype Toyota PHEV,  basically a Prius with a 10 mile range battery in the trunk.

Ron Grebman of CalCars wrote a terrific analysis whether GM or Toyota is correct in asserting that their PHEV architecture is superior.

He starts off noting that the most important benefit of a PHEV is its ability to displace liquid fuel consumption by power from the grid.

Thus he argues, the core argument in determining which vehicle is superior is to measure how much fuel is displaced in normal driving.

Charge depleting mode is explained as occurring when the car is driving electric only and blended mode is when both battery and fuel are used. Charge sustaining mode occurs in the Volt only when the battery reaches its target depth of discharge, but in the Toyota-type parallel hybrid it is at all times. Degree of blending varies by how fast a parallel hybrid is allowed to drive on electric only, this is called a “utility factor”. In the case of the Toyota that’s 62 mph, for the Volt 100 mph (max).

He tells us interestingly that a gallon of gas holds 33 kwh of heat energy, and considering hybrid efficiency of 30%, 10 kWH of battery power represents roughly one gallon of gas, and costs $1.00.

Grebman notes the core argument between GM and Toyota is that GM says the Volt can drive 40 miles on all official driving cycles in pure-EV, and that only a car that does so could obtain maximum PHEV benefit.

Toyota admits that the prototype PHEVs remain blended (parallel) but argue that the cost will be less, because of battery smaller size, they also argue that the ratio of fuel displacement to battery size is greater than in the Volt.

He compares the Volt and Toyota PHEV in a table, telling us the latter has a 5.2 kWH NiMh pack with 4 kWh usable power, and demonstrates that fuel is consumed in it at all driving distances.

My take on the conclusion is basically that the E-REV (Volt) is best because it can displace more petroleum overall as well as reduce greenhouse gas and tailpipe emissions. In the current market, the Toyota-model PHEV gives a cost benefit because of the less expensive battery and control electronics. This advantage could be eliminated if fuel costs continue to ride.

Once battery prices drop, or fuel prices continue to rise, both of which are likely to happen, pure EVs will become the standard.

Source (GreenCarCongress)

GM has announced its intention to produce a plug-in Saturn VUE with a large lithium ion battery married to a 2-mode hybrid drivetrain.  This car quite possibly could be the first-ever plug-in hybrid that gets brought to the U.S. market.  I had the chance to ask the vehicle’s chief engineer a few questions.

When will the plug-in VUE come to market?

We haven’t announced a production date yet.

Do you have a time frame?

For the plug-in, it will go into production as early as 2010. If you look at the development path for the Volt and you look at the development path of the plug-in VUE, they are similar.

Can you tell us what the plug-in VUE’s battery size will be?

We’re not going to go into that level of detail right now. Its definitely going to be lithium-ion.

Is a 10-mile EV range what is expected?

That’s a very reasonable expectation. When you do a plug-in what you want to do is you want to maximize the amount of range you can get from a charge-depletion mode. So when you run only on the battery, situations when you run totally on the battery, totally on electric mode, but in reality were going to have a blend of gas and electric depending on cold start up or emission or things like that. But by and large when you are running on the overall charge depleting mode, thats when you are going to generate that very high fuel economy .

Is the design for the first 10 miles will the car be capable of handling any driving requirement electric only?

Yes, but the thing you’ve got to remember is that it may not always be the most efficient to run only on battery under all conditions. So technically it will be capable of it, but will it in all cases? Probably not. One of the thing s we pride ourselves on is how you best integrate the vehicle. How you balance all the different environmental aspects, the emission aspects, the cost of ownership. Sometimes its not the most economical to run on battery. So we make those decisions. That why you’ve got all the high power controls that are in the vehicle.

So it might use gasoline even in the early miles?

Exactly. The thing we look at is charge depletion. How much fuel economy can you get during the state of the battery when you’re actually using it.

So when you reach the charge depletion point and go into hybrid mode, the battery can still participate in driving the car past the EV range?

Absolutely, just like a hybrid does.

Will the battery be recharged all the way or will it operate at a lower level?

Theres a lot that we need to figure out, but the basic operation is you can charge it to the point where it can run off charge depletion again.

So it has a list of three driving operations that it can do at anytime; charge depleting, charge-sustaining, and gasoline combustion?

That’s the benefit of having a larger battery. Thats why you want a lithium ion battery. You can put the energy into the battery when you have the opportunities to do so and then take advantage of them later.

Do you currently have any working prototype vehicles?

We have some very early vehicles. Mules is exactly the word that we use.

Do they have functioning packs and drivetrains?

Yes, absolutely.

Can you say which battery vendor is making the pack?

No.

Are there several different contributor companies?

We have not yet made a selection. A lot of companies are in the mix. There will only be one when we go into production.

Are there any technological hurdles that you’ve yet to achieve?

Of course. If you look at the difference between and two-mode VUE and a plug-in VUE whats the difference fundamentally its’ the battery. Its widely understood in the industry that lithium-ion batteries represent a challenge.

So you’re using nickel-metal hydride in the 2-mode?

Yes

What do expect the fuel economy to be in the 2-mode (non plug-in)?

We don’t have our numbers yet. There have been a lot of reports where people reported erroneous information. What we’ve said is that we are projecting at least 50% improvement in combined fuel economy. The equation is 55% city, 45% highway. Right now we are confident in our ability to achieve greater than 50% combined, we’re not stating the label at this point. We have to get a lot closer to our launch date before we do that.

Is it front wheel or all-wheel drive?

Front. The comparison is relative to the VUE XR front wheel drive, which is 16/23 city/hwy. The 2-mode system gives us some real opportunity because of the way we designed the system to a peak efficiency point to generate some very significant highway fuel economy.

So this car will help you align to the future CAFE standards?

Its certainly part of our strategy. All of the auto manufacturers have know change is coming we haven’t known exactly what they were except that they would be significantly increased from where they are today. The hybrid alone won’t get us there. Its the hybrid plus many other strategies that will allow us to meet those standards.