Plug-Ins Going for a Spin

By Michael Taylor
The San Francisco Chronicle

Wednesday 31 October 2007

100 Northern California households to put modified Priuses through their paces.

Davis - One hundred Northern California households will be given the use of experimental, plug-in hybrid cars next year in the first widespread consumer testing of the super-high-mileage vehicles in the nation, under a program announced Tuesday by UC Davis transit planners and an auto club.

The households, to be chosen from the ranks of more than 4 million members of AAA of Northern California, will each have an eight-week loan of a Toyota Prius converted to run on batteries that are twice as powerful as those originally installed by the automaker.

The cars can easily get 100 miles per gallon on their combined power from electric motors and gasoline engines. They also spew out far fewer environment-harming emissions than even conventional hybrid cars.

"This is the first large consumer study of plug-in hybrids," said Tom Turrentine, director of the Plug-In Hybrid Center at the UC Davis Institute of Transportation Studies. "We're the advance guard of putting a lot of these (cars) in households." The program is scheduled to start in the spring of 2008.

Plug-in hybrids are in their infancy - perhaps 50 of them are in fleets maintained by utility companies, universities and other organizations - and so far there has been no large testing of how they work in everyday use.

Normal hybrids use a combination of electric and gasoline power to eke out better mileage than gasoline-only cars, largely by having the electric motor take over in situations where the car does not require much power, such as crawling down a city street or in a freeway traffic jam. The electric power is created by on-board generators and regenerative braking, freeing the car from the leash of a power cord and hours of recharging t

Plug-in advocates say the converted hybrids constitute the best of all worlds: By equipping the car with more powerful batteries and then letting them recharge overnight, the next day's journey can be done mostly on electric power, saving the car's gasoline engine for more stressful situations such as zooming onto a freeway or for long-distance travel.

The downside of plug-in hybrids, critics say, is that the converted cars, by using household electricity for daily recharging, are simply sucking more energy from the already polluting coal-fired power grid, and that in the long run this is just as bad for the environment as having a gasoline-only car.

Turrentine conceded that the United States "should clean up its coal-fired plants," but said that in states such as California, which gets much of its power from cleaner sources such as hydroelectric plants, plug-in hybrids will only help.

The 10 Priuses to be used in the test are being turned into plug-ins by Pat's Garage, a San Francisco firm that has been doing such conversions for several years. Each car costs about $15,000 to convert. The program is being funded by the California Energy Commission and the state Air Resources Board.

Driving a plug-in Prius is much like driving a normal one. The major difference is that the car is more silent than a conventional hybrid because its electric motor is whirring away far more often than the gasoline engine.

"We're going to be interviewing households every week," Turrentine said. "We want to know how people respond to the car. Are they excited because it is cheaper (to operate)? Are they excited because they are saving the world?"

The guidelines for choosing test households are pretty simple: The program is seeking people who have a garage, carport or parking place with a nearby 110-volt outlet and who will not only be willing to plug in their hybrids every night but will remember to do it. Turrentine also said they will be seeking people with daily roundtrip commutes from 20 to about 120 miles.

He said the type of households chosen for the plug-in exercise will have different lifestyles - "it could range from a typical American family to a young urban dweller to a retired couple living in Tahoe."

UC Davis officials said AAA plans to select program participants from the association's member rolls, rather than open it up to volunteers.

AAA senior vice president Alexandra Morehouse said her organization got involved because "our members are overwhelmingly interested in alternative-fuel vehicles. Our mission (in this program) is to get people to think, 'I could drive a plug-in hybrid electric vehicle. It's not that different, and it could be part of my life.' "