Green Thoughts

Chevy Volt: “Dawning of a New Era” or “Won’t Get Fooled Again”? January 23, 2007

On Jan 6th at the North American International Auto Show in Detroit, GM unveiled a new car that seems to position it again in the horse-race for the green car of the future. In the last few years, GM has been the target of criticism from green car advocates for its destruction of the EV1 program. Chris Paine’s “Who Killed the Electric Car” chronicled GM’s missteps in backing out of producing the EV1 and then scrapping the remaining cars despite a loyal following and the negative PR that it generated.

Thus it was something of a surprise that GM has now, with the unveiling of the Chevrolet Volt concept car, invested intellectual capital into electric drive vehicles at least in the concept stages. The Chevrolet Volt is an aggressively styled, sporty hatchback concept that uses what it is calling its new drivetrain platform, the “E-flex Electric Vehicle System”, to propel it. Like the more familiar Toyota Prius, Lexus GS450h and Honda Civic Hybrid, the Chevy Volt has both an electric motor and an internal combustion engine (in some configurations).

Chevy Volt: The Theory

Crucially, however, the Volt is designed to be a “series hybrid”, meaning that the only motor that drives the wheels is the electric motor, while the gas- or maybe diesel-powered internal combustion engine is used simply as a portable generator to supply electricity to the electric motor when its large battery banks have been depleted. The electric motor and the gasoline engine are arranged in series, rather than in parallel, as they are in the Prius and all existing hybrids on the market currently. The parallel hybrids like the Prius use a complex transmission system to alternate between using the electric drive motor OR the internal combustion engine to drive the wheels, depending upon the demands placed upon the vehicle and the state of charge of the battery. The now common parallel configuration has been developed more fully even though it is much more complicated than the series configuration of the Volt, which needs a less complex transmission and drive system controllers.

The Volt is also different from the Prius and existing hybrids on the market in that it is conceived of as a Plug-In Hybrid or PHEV. All hybrids currently on the market derive their energy entirely from fossil fuels, albeit in a way that uses some of the efficiencies of the electric drive to use less fuel. The Volt will be a PHEV, meaning that it can flexibly use power from the electric grid via a plug to charge its relatively large battery bank. The plug-in system will allow for charging at ordinary household voltages but may in addition allow for an additional higher voltage quick charge interface, if quick charging stations become available as a home installation or in public places. The Volt’s drive system will in addition be set to “prefer” to use the charge already in the batteries to power the vehicle rather than use the power generated by the on-board generator. Publicity materials currently claim that the fully charged Volt will travel its first 40 miles entirely on battery power before starting up the generator to recharge the batteries. Citing the average American needing to commute 20 miles to work per day, GM has designed the size of Volt’s battery pack to allow it to operate almost entirely using charge from grid electricity for average daily use and only to use fossil fuels as a range extender for longer trips.

Finally, GM’s E-Flex Electric Vehicle System, for which the Volt is the first concept design, has one more, clever trick up its sleeve: a flexible, modular design with regard to what type of electric generator it uses. The Volt could use a gasoline combustion engine, a diesel engine, or any number of different types of fuel cells (hydrogen among them) to generate the needed electricity from a hydrocarbon or other non-electric fuel source. The initial design uses a turbocharged 1 liter, 3-cylinder gasoline engine. The Volt would have a 640 mile range on a full battery charge and a full 12 gallon tank of gas. Cleaner and greener alternatives that would substitute for the gasoline powered generator are possibilities in the future, therefore the “flex” part of the E-Flex system.

It doesn’t hurt that the Volt Concept’s body shape is aerodynamic, muscular and not too unconventional, with aggressive styling that borrows from GM’s current design language and echoes of the new Camaro concept. For the practical hatchback body style, it is a very successful look, especially if the concept’s lines and detail can be successfully carried over to the production model.

Chevy Volt: Practice

While the design of the Chevy Volt and its E-Flex powertrain is grabbing attention and winning mostly kudos in the press and among green car advocates, including filmmaker Chris Paine, who made “Who Killed the Electric Car”, more potential controversy emerges when and if the “theory” will become practice. GM and other major manufacturers can produce concept vehicles without of course committing to producing them…such is the nature of the concept vehicle. GM is in fact interested in knowing what kind of response people have to the idea of the Volt through their website:

http://www.gm.com/company/gm_exp_live/events/naias_2007/index_flash.html

If you want to let GM know what you think of the Volt, you can let your voice be heard at the link above.

GM has chosen its most economical Chevrolet brand as the initial home for the Volt and has suggested that it is targeting a price point of the equivalent of $25-30K current US dollars in its base configuration (40 mile all electric and 3-cyl gasoline generator). If it were to pick a higher price point, the car could be built sooner as more expensive batteries could be used.

The motors for the Volt are relatively uncontroversial both in technological and economic terms. Brushless DC electric motors and 3-cylinder turbocharged engines are not major technological innovations though the optimization of each of these for a new task would take time. They do not require the use of many exotic and expensive materials either.

Weight-saving features in the body and chassis and therefore expense might be cause for further revisions in the Volt’s production and marketing plans. The use of advanced materials may boost the overall cost of the vehicle’s structural components but may allow for lower costs for energy storage and vehicle power.

Beyond lightweight composites and plastics, there are two main X-factors in the actual implementation of the Volt design into a production vehicle, one related to GM’s corporate commitments and the other technological. The commitment X-factor has to do with GM’s ability to see through a radical departure from current thinking and its current stance vis-à-vis the market. Having seen GM scrap the EV1 in such a foolish and short-sighted manner, most observers are taking a wait-and-see attitude about how much spirit and money GM can put into a radical re-direction of a portion of the company away from the gas pump and into the world of electric propulsion. GM would have to take, at least among the Detroit automakers, a market leadership position for the first time in a very long time, conditioning demand with its product offerings rather than pandering to the most traditional expectations of potential U.S. car buyers.

The other X-factor is a challenge faced by all manufacturers of electric drive automobiles: the capacity, safety, weight, and longevity of the battery pack and to a lesser extent charging characteristics of the batteries. At the turn of the 20^th Century, electric automobiles lost out to gasoline-powered vehicles due to the limited energy capacity and weight of battery packs. GM says that it will use a lithium ion battery pack when a pack of this size will cost approximately $5000 for enough energy to power the Volt 40 miles an amount of energy that GM currently estimates at 16 kWh (kilowatt-hours). By contrast, Tesla Motors has built a 56 kWh 400kg battery pack for the $90K all-electric Tesla roadster with a range of around 250 miles on a full charge.

GM says that the “batteries are not there yet” and this is probably one of the more controversial statements within their public statements around the Volt. Some say that they could make this happen sooner than 2011 or 2012, especially if they set the price point for the Volt higher. Putting together a fairly lightweight 16 kWh battery pack using advanced Lithium Ion batteries just emerging on the market from Altair Nanotechnologies or A123Systems, seems not to be too difficult.

Others support GM’s contention about the batteries not being ready but from the perspective of encouraging a still larger battery pack and an all-electric design. Tesla’s CEO, Martin Eberhard, points out that a smaller battery pack will stress the batteries more and shorten the lifespan of the battery pack as a whole according to the research that they have compiled at Tesla. A larger battery pack allows individual cells to be partially charged which lengthens their lifespan. This contention supports Tesla’s production and marketing plans which foresee an all-electric compact car at a $30K price point with a greater than 200 mile range emerging from Tesla somewhere in the time frame 2010-2013.

The weight of the battery pack is important, as the heavier the battery pack, the more energy needs to be expended and stored to move that battery pack. Lithium ion is the most promising battery chemistry as advances in lithium batteries are an extension of existing work in battery miniaturization for computers and personal electronics. Within the arena of lithium chemistry, there are many competing technologies that look to revolutionize the energy density (energy per unit weight), power density (energy output per unit time per unit weight) of batteries, charge-recharge speed and durability, safety, and temperature sensitivity of batteries. There are additionally rumors that EEStor of Austin Texas has a revolutionary ultra-capacitor with even more favorable energy/weight ratio and charge/discharge characteristics.

Chevy Volt: “Dawning..” or “Won’t Get Fooled…”

The announcement of the Chevy Volt is clearly a great public relations coup for GM if not actually a sign that this US car-making giant will be able to do battle with Japanese and smaller carmakers to help shape a sustainable automotive future. GM’s design for the Volt is a sign that some people at GM and perhaps the GM leadership have actually been listening, watching and learning from developments in both the automotive world and in the world in general. The E-flex architecture, at least in its conceptual design, answers many concerns people have about electric drive vehicles: range, cost, recharge/refuel speed. The choice of a serial hybrid design, a first among both major and smaller automakers, gives GM space to develop a core strength among greener designs.

The E-flex architecture in addition allows GM freedom to experiment with a number of different portable electric generators with varying costs and carbon-releasing characteristics. Personally, I believe the development of alcohol and other liquid hydrocarbon fueled fuel cells are the best stopgap to the mostly-electric future and am less enthusiastic about the hydrogen variety. Fuel cells can be much more efficient than an engine in generating electricity from combustible fuels of either renewable or fossil origin.

Can GM be taken seriously? Unlike in the 1990’s, GM can no longer afford to disappoint expectations in the green vehicle area, and the historical context is now different: carbon emissions effect everybody while the EV1 was at the time largely a product of local air pollution mandates in California. U.S. and European based carmakers take the Japanese and soon the Chinese manufacturers more seriously than before. GM, with the announcement of the Volt, has at least signaled an interest in an area that has not yet gotten the full attention of a major automotive research department. If carbon taxes or the like are introduced, the E-flex architecture could give GM a leg up over other major automakers.

While the Volt may not actually be delivered, its announcement will have major effects on the marketing and design of electric vehicles from major and specialized manufacturers. GM has thrown in a “maybe” into the debate about what is most practical AND sustainable path to a greener automotive future. If it can follow this up with a greener production vehicle, that will be better for all, even if it means that its competitors must demonstrate more vigorously the effectiveness of their present and future products.

It IS then, in my opinion, the dawning of a new era, though not necessarily one in which GM will end up leading us into the electron economy, the vision of a future energy system that relies on electricity as the primary energy carrier rather than fossil fuels. GM has a lot to prove in terms of its ability to hold a lead in automotive research or envisioning a (sustainable) future. What is more likely is that competition and cooperative efforts will intensify to find more than one solution to the question of how we will replace fossil fuels in our transport systems. More and more companies will weigh in on the crucial area of battery technology, as did Mitsubishi earlier today. GM’s announcement of the Volt is a very loud salvo but is by no means the last shot to be fired.