Range Anxieties: What Lies Ahead for Plug-In Hybrids

[David A. Kates]

The forces of automakers and policymakers responding to the public's demands for fuel-efficient, less petroleum-based transportation will soon collide to bring plug-in hybrid-electric vehicles to the world stage. Most of the major car companies are testing small numbers of plug-in vehicles. General Motors has promised to debut its Chevy Volt in dealerships next year; Toyota will start leasing its plug-in Prius at about the same time but has yet to announce production plans.

These are exciting days for green cars. But there are plenty of unknowns about the technology and customer preferences that make automakers and advocates jittery.

Car makers believe the public has "range anxiety" with battery-electric vehicles. Insufficient all-electric range could cause drivers to be stranded somewhere. Instead, automakers have favored plug-in hybrid-electric vehicles because of their back-up gasoline engines.

"In the case of those hybrids that get about 40 miles of all-electric range, you can have all the benefits of the battery-electric car five days a week," said Edward Kjaer, director of electric transportation for the utility Southern California Edison. "And then on that sixth day, or whatever, if you have to do a long-distance drive, it's not a problem."

But most consumers, especially in Europe and Asia, don't even need a 40-mile all-electric range for their commutes. Auto engineers, therefore, want to make the battery as small as possible.

"When you go to plug-in hybrids, you start asking yourself, 'How small can I make that battery and meet the everyday needs [of drivers]?'" said Ichiro Sugioka, science officer for Volvo Car Corp.

Batteries are expensive (currently about $1,000 per kWh) and heavy, which affects the efficiency and performance of the vehicle.


The Chevy Volt, with its 16 kWh battery, is designed to have a 40-mile all-electric range, while the Toyota Prius plug-in is likely to have about a 10-mile range. (Toyota's plug-in Prius at the 2008 Paris Motor Show had just a six-mile all-electric range but charged in an hour and a half.)

Andrew Frank, a professor of mechanical and aeronautical engineering at the University of California, Davis, believes Toyota has the better strategy. He speculates that the company will be able to sell the Prius for less than the Volt because of its smaller battery.

"As far as I can see, the best way to do this is to have a person charge every time he parks and to create an infrastructure so that's possible," said Frank, who also works with Efficient Drivetrains, Inc. (EDI). "And if you do that then it doesn't make any sense to have a 40-mile all-electric range."

Yet a number of green car analysts believe the Prius' all-electric range is insufficient for American customers. "Toyota is selling the technology short" with a range too far under the 20-25 mile sweet spot for most drivers, said Felix Kramer, founder of CalCars (the California Cars Initiative), which advocates for plug-in hybrids.

Unlike some plug-in prototypes (such as the Volt and Fisker Karma), the Prius will probably be a blended hybrid, meaning that the gasoline engine will kick in when the car reaches about 50 mph or if it accelerates too quickly.

Kramer, however, thinks General Motors could have started with a smaller battery for the Volt, making it more affordable. (Even with the $7,500 federal tax credit, the Volt will probably retail for $30,000-$35,000. Mass-produced plug-in hybrids will eventually have a $3,000-$5,000 premium over conventional hybrids, he said.) A 40-mile all-electric range would satisfy the commutes of more than 70 percent of Americans. A 20-25 mile all-electric range is a better balance because it would satisfy the commutes of about 50 percent of Americans and would require smaller (and less costly) batteries, Kramer said.

The U.S. Dept. of Energy's Office of FreedomCAR and Vehicle Technologies, which develops plug-in hybrids, set the goal of producing a vehicle with a 20-mile all-electric range between 2012-2016 and a 40-mile all-electric range between 2016-2020.


Volvo announced last month that it will start leasing its V70 model as a diesel plug-in hybrid to utilities and other customers in Sweden. The three demonstration vehicles will feature an 11.3 kWh lithium-ion battery pack that can be recharged in five hours using a standard wall outlet. It will have approximately a 30-mile all-electric range. [See HybridCars.com]

The automaker teamed with Swedish energy firm Vattenfall, which will build public and home-based charging stations offering electricity from renewable sources. The two companies will conduct research on the mileage and performance of the vehicles before they are mass-produced in 2012. A key concern is selecting the correct size of battery since it will be a major part of the retail cost. Sweden hopes to become the world's first oil-free nation by 2020.


False Anxieties?

All of this optimal range discussion may be fruitless, at least for the first generation of plug-in hybrids.

"You can't really define one range because it depends on which customer you're targeting and what uses you're targeting," said Volvo's Ichiro Sugioka. People who primarily drive to the grocery store and back would be fine with a short all-electric range (and still not use gas).

Actually, neither an all-electric range nor a charging infrastructure are necessary because of the hybrid's engine, Sugioka said. (Although the likely draw of hybrid-electric vehicles will be the ability to drive without petroleum.)


Infrastructure

Battery-electric vehicles have been driven in California since the 1990s because of the investments in charging infrastructure that the state made.

"... A battery-electric car absolutely works in an urban commuting situation," Edward Kjaer said.

Kjaer has driven Edison's fleet of Toyota RAV4 EVs for 13 years. Just one-percent of the time has he had to use his family's gasoline car or rent a car to make a road trip, according to Kjaer.

The most important charging spots are at home and work because people typically spend eight hours a day at each location. Some employers give perks to EV drivers by putting charging stations next to the most convenient parking spaces.


Public charging at shopping centers and other high traffic locations will be necessary, as well. On highways, fast-charging stations that could replenish batteries in 10-20 minutes (depending on the state of discharge) would be most convenient, Kjaer said. Mitsubishi recently partnered with Southern California Edison to test their battery-electric vehicle, the i MiEV, with fast-charging capabilities.

Another future technology that will make charging easier is auto docking, or automatic charging. A parked electric vehicle will be able to inductively charge through a contact or plate in the ground without plugging in.

In the mean time, public agencies and automakers will have to educate people about how and where to charge plug-in vehicles.


Batteries

Batteries are the biggest expense for a plug-in hybrid, adding $5,000 or more to the vehicle's cost. In response, General Motors has considered leasing the battery pack for the Volt. (Norway's Think is also discussing this for its battery-electric vehicle). Project Better Place, a multinational company, will exchange depleted batteries for fresh ones at charging stations on a subscription basis.

The U.S. Dept. of Energy's plug-in research team hopes to produce a battery for just $300 per kWh by 2012 and $200 per kWh by 2016. Experts believe these cost reductions are possible in the next five to ten years with much higher volumes of production and more mechanization. In turn, the total cost of plug-ins will come down.


"This is a marathon that we're on," said Edward Kjaer "It's not going to be all or nothing by first generation. But certainly as the batteries get better and we come down the volume-price curve, that means we'll start to get more all-electric range on the vehicles."

Early adopters will likely be technology addicts and environmentalists who want to be the first in their neighborhood to own a plug-in and are willing to pay a premium.

"The real question is how quickly we can migrate from that early-adopter, high-cost position, where volumes will be relatively small, to a more mature mass-market position where we have real public offerings at reasonable costs that you and I can buy," Kjaer said.

Government, no doubt, will be key in propelling the market.