When General Motors unveiled the Chevrolet Volt concept car at the Detroit Auto Show in January 2007, it rocked the green-car world. Its technology—still a lab experiment, then—instantly leapfrogged standard hybrids (like the Toyota Prius) and even hybrids that had been adapted to recharge their battery packs from the power grid, known as “plug-ins”.
Nearly two years later, the Volt is a small, five-door hatchback, roughly similar in shape and accommodation to the Toyota Prius and Honda Insight. Final production styling was unveiled at GM’s 100th birthday celebration in September 2008. The look of the production Volt differs quite a bit from the concept in order to offer the best possible packaging with extremely efficient aerodynamics to minimize battery draw.
GM calls the Volt an “extended-range electric vehicle” (or E-REV.) This underlines its crucial point of separation from other hybrids: It operates entirely as an electric car for its first 40 miles after a full charge. It burns no gasoline during those miles, drawing energy from a 400-pound lithium-ion battery pack containing 16 kilowatt-hours (kWh). Current from that pack powers a 150-hp electric motor that drives the Volt’s front wheels.
But a 40-mile range isn’t enough to make a car practical, so the Volt also carries a 1.4-liter flex-fuel engine. Crucially, that engine doesn’t drive the wheels—it only kicks in to power a generator that recharges the battery enough to give the car another 300 miles of range. And that only happens once the battery is exhausted.
Chevy Volt as Series Hybrid
This arrangement is called a “series” hybrid. It’s fundamentally different from a “parallel” hybrid, like the Prius, in which the car’s electronic control unit constantly switches between the engine and a much smaller battery pack (about 1 kWh). While the Volt is an electric car with an engine for backup, a Prius is mostly powered by its engine. The Prius battery stores regenerated braking energy, helps with acceleration, and provides a very small amount of low-speed electric functioning.
Assuming that the Volt goes on sale in November 2010—lately GM has spent less and less time qualifying that goal with, “If the batteries are ready”—it would be the first series hybrid sold in volume anywhere in the world.
Why 40 miles of electric range for the Volt? Because more than two-thirds of Americans drive less than 40 miles a day. If those people plugged in their car to recharge it every night, they might never use any gasoline. And depending on local electric rates, that 40-mile recharge might cost less than a dollar.
The Volt comes with an onboard battery charger that handles any type of household current—both standard 110-Volt, and the 220-Volt variety used for heavy appliances like refrigerators and washing machines. A full recharge takes up to 8 hours on 110V power, and about 3 hours using 220V.
The Volt is built around a set of components GM calls "E-Flex.” It is based on driving the wheels electrically; the only thing that powers the car is an electric motor. But many different types of range-extenders can supplement the battery: an engine running on gasoline, diesel, or biofuels, perhaps even a hydrogen fuel cell.
While the Volt is the first car to use this architecture, it won’t be the only one. GM plans to use a similar battery pack and motor combo to power vehicles from its Opel brand in Germany, and future Saturn and Chevrolet models.
Volt Plaudits, Plus Cynicism
On introduction, the Volt concept was hailed for its technology, not to mention the racy lines of the concept—known inside GM as “the electric Camaro." But it garnered quite a lot of cynicism too. With the movie “Who Killed the Electric Car?” still resonating in early 2007, commentators said the Volt was nothing more than “greenwashing,” that it was only a PR exercise, and that GM had no real interest in improving fuel economy.
One critic at the time was Dr. Walter McManus, an auto industry economist at the University of Michigan. “Now they have come up with another future magical technology that isn't quite ready yet,” he said at the time. “They will tell you they are doing everything they can to improve the internal combustion engine. I don't buy it."
Over time, skepticism has faded somewhat. That’s due in part to efforts by GM’s PR group to be unusually transparent about the Volt’s development, timetable, and technical challenges. The company has brought dozens of journalists into its development labs, letting them interview vehicle executives, visit testing facilities, and see in-process styling mockups. GM executives have repeatedly called the car “our most important project."
The most critical aspect of the Volt is its lithium-ion battery pack. Unlike the Tesla Roadster, which uses 6,831 commodity mobile-phone batteries in its pack, the Volt will use 250 larger cells, provided by one of two companies currently competing for the supplier contract: LG Chem or A123 Systems.
Both prospective cell-makers have partnered with other companies that have designed and supplied the actual battery pack that uses those cells: Compact Power Inc. and Continental AG, respectively. This means, however, that GM is relying on outside suppliers to provide the most crucial element of its most advanced vehicle.
If all goes well, GM says, production Volts will go on sale in November 2010. The price tag is a source of much debate, with recent estimates between $32,000 and $40,000—much of it due to the cost of the advanced batteries. GM is pushing for a Federal tax credit of up to $7,000 to offset some of that cost, but there’s no question that the Volt will be far pricier than conventionally powered vehicles of a similar size and capacity. Even with the tax credits, GM might lose money on each Volt it sells. The company plans to build 10,000 Volts the first year, and perhaps as many as 60,000 a year after that.
Questions Remain About Chevrolet Volt
Many questions remain: How long is General Motors willing to subsidize the Volt? How long before the lithium-ion batteries can be produced in volume? Will those cells be made in North America, or imported from Asia? And how long until we see the Chevy Volt at local dealerships throughout the country, and not just the handful of states and cities where it will first launch?
Any number of forces and circumstances could still derail the Chevy Volt. But at this point, it almost doesn't matter. Still two years away from delivering a single vehicle, GM has already scored a big victory by putting the company back into the national conversation about auto technology, energy policy, and the environment.
The Volt has also forced GM’s arch-rival Toyota to speed the pace of its own plug-in hybrid program. With energy security, the price of oil, and climate change all rising in public awareness, the timing for the Volt seems perfect. In fact, many of the growing legions of Volt fans now say simply: It can’t get here soon enough.
