GM Defends Chevy Volt; Calls Critical Study Faulty

By dancurranjr On March 6th, 2009

chevrolet-voltA study by engineers from Carnegie Mellon University examining the economics of electricity-intensive “plug-in” hybrid-electric vehicles – a coming class of high-efficiency models typified by General Motors Corp.’s 2011 Chevrolet Volt – bases its primary argument on an outdated assumption, said one of GM’s highest-ranking engineers.

The Carnegie Mellon study concluded that plug-in hybrid-electric vehicles (PHEVs) using large, high-capacity battery packs to enable propulsion for comparatively long distances solely on electric power are not the most economically viable path to higher-efficiency vehicles. It said PHEVs with more modest and less-costly battery capacity are the optimum approach.

GM’s highly publicized Chevrolet Volt is categorized by the company as an “extended-range” electric vehicle, but in effect is a PHEV with the kind of large-capacity battery capability the Carnegie Mellon study said is not a cost-efficient solution.

Jon Lauckner, GM vice president-global program management and a high-level engineer with deep involvement in the Volt’s development, told AutoObserver in an interview Monday that there are valid points in the Carnegie Mellon study – but its dismantling of extended-range PHEVs because of high cost is mistaken because the researchers are ill-informed about the cost of new-age hybrid batteries.

Battery Cost Mistake ‘Jumps Off The Page’

The mistake in the study that “jumps of the page,” Lauckner told AutoObserver, is the GM Jon Lauckner.JPGassumed baseline cost of the lithium-ion batteries used by the Volt and, most likely, other future PHEVs: $1,000 per kilowatt-hour.

“That’s very high compared to the cost we’re paying today,” said Lauckner of the Volt’s prototype lithium-ion batteries developed by Korean battery expert LG Chem. “And very, very high compared to the (battery cost) in the near future,” once even modest engineering improvements and economies of scale kick in, Lauckner added.

“For me, the conclusion they draw is very much dependent on what they think longterm battery costs may be,” he said. And the researchers’ battery-cost forecast, ignorant of the latest battery developments, is seriously pessimistic.

He said using the Carnegie Mellon formula, the Volt’s battery pack alone, planned with a capacity of some 16 kWh, would cost $16,000.

“I won’t tell you what that battery pack is going to cost,” when the Volt goes into production in December 2010, said Lauckner – but he insists it’s nothing near the $1,000 per kilowatt-hour on which much of the Carnegie Mellon study’s cost-benefit equation is based.

Batteries Will Cost Less – Maybe A Lot Less

He said university researchers do acknowledge that in their methodology, battery cost plays Chevrolet Volt battery testing – 114.JPG prominently in determining whether PHEVs with large battery capacity – and proportionately lenghty electric-only driving distances – make economic sense when compared to less-capable PHEVs or conventional hybrids.

The Carnegie Mellon engineers do indicate in the study that a significant reduction of battery cost would change the playing field, acknowledging, “Cheap  battery costs of $250 per kWh would significantly increase competitiveness of PHEVs, making them similar to or less expensive than HEVs and (conventional vehicles) across all distances driven.”

Lauckner said a chart presented in the study proves the point that battery cost of significantly less than the study’s “baseline” of $1,000 per kWh improves the overall cost-competitiveness of PHEVS: when battery cost is assumed to be $250 per kWh and battery recharges occur close to the 40-mile intervals for which a PHEV such as the Volt is designed, the PHEVs are almost equal in cost with less battery-intensive PHEVs and even conventional hybrids (note “low battery cost” segment of chart).

“We’re definitely not as high as $1,000 per kilowatt-hour,” he insists. “That’s way high.”

Customer Incentives Reduce Cost

Lauckner said the researchers also fail to take into account another factor: the “already legislated” consumer incentives for plug-in hybrids indexed to their battery capacity. The Chevy Volt is in line to deliver a $7,500 tax incentive to customers. The amount that comes directly off the buyer’s federal tax owed will be much less for the PHEVs with just seven to ten miles worth of electric-only battery capacity the study claims is ideal.

In discussing “cost,” he allows that the Carnegie Mellon engineers may be talking broadly about the various hybrids’ societal costs, but said the fact remains that buyers’ out-of-pocket costs for all PHEVs will be markedly reduced by the tax incentive.

Where’s The Recharging?

Lauckner lobs one final volley at the Carnegie Mellon research, which said the lower-capacity PHEVs are the most cost-efficient relying, in part, on the assumption they can be recharged after approximately every seven miles of electric-only driving.

That assumption is invalid, said Lauckner, because it does not reflect either the reality of a widely available recharging infrastructure – which is all but nonexistent at this moment – or applicability to real-world commuting, which would require low-capacity PHEVs to use their combustion engines much more extensively than PHEVs with large battery reserves.

“How many people are going to stop every ten miles or less and recharge for a half-hour?” Lauckner asked. He added that even if they would, there is no definitively plan for an extensive recharging infrastructure anywhere in the nation – much less funds earmarked to pay for it.

He said use of smaller-battery PHEVs in the most optimal fashion envisioned in the study “absolutely requires (recharging) infrastructure. It may be what the numbers tell you – but it’s not practical.”

SOURCE: Edmunds Auto Observer

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