It’s a hot and smoggy day in Washington, DC, and things aren’t going well for Les Goldman, a longtime energy lobbyist whose latest project is a new kind of car that is supposed to slash gasoline consumption and reduce greenhouse-gas emissions. We’re outside his office, a block from the White House and a quick trip down Pennsylvania Avenue from Capitol Hill. And Goldman is sweating at the back of the “plug-in” hybrid that I’m supposed to test-drive, checking electrical connections and trying to figure out why it isn’t working.
The car is a modified Toyota Prius with an extra battery installed in the spare-tire compartment. Conventional hybrids like the Prius run on an electric motor part of the time, but the electricity they use is generated by a gasoline engine and by capturing energy from braking. In the plug-in version of the car, the extra battery can be recharged from an electrical outlet. The battery stores about 40 miles’ worth of electricity; if it’s depleted, the car reverts to conventional hybrid mode.
The few plug-in vehicles on the road today are prototypes that, as Goldman is discovering, aren’t always reliable. But recent advances in battery technology have attracted the attention of major manufacturers, raising the possibility of a mass-produced plug-in car. General Motors has announced that it is developing plug-in hybrids that use advanced lithium-ion batteries and could be ready within a few years. One of the GM designs–for a car known as the Volt–calls for a gasoline engine that kicks in after 40 miles just to recharge the battery. Toyota also says it is researching lithium-ion batteries and testing plug-in vehicles.
An electric battery with a 40-mile range could nearly eliminate trips to the gas station for many drivers, since Americans drive just over 30 miles a day on average. But unlike earlier, all-electric cars, the new hybrids could handle longer commutes; the Volt is designed to travel 600 miles using its backup gas tank to charge the battery. And electricity from the grid is cheap: the equivalent of a gallon of gas costs less than a dollar.
The environmental arithmetic is also favorable. Generating the electricity to power plug-in cars causes less greenhouse-gas pollution than burning gasoline does, according to a recent study by the Electric Power Research Institute and the National Resources Defense Council. Even in the worst-case scenario, in which a plug-in vehicle got all its electricity from coal-fired plants (in reality, electricity in the United States comes from a mix of sources that on average release less carbon dioxide than coal plants do), it would still be responsible for a third less greenhouse-gas pollution than a conventional car. And though plug-ins and conventional hybrids would account for similar amounts of greenhouse-gas emission in most parts of the country, plug-ins in areas with clean sources of electricity, such as hydroelectric power, would be responsible for about half the carbon dioxide emissions of other hybrids.
Unlike other alternative technologies, such as cars powered by hydrogen fuel cells, plug-ins don’t require any significant new infrastructure. Existing gas stations would provide the fuel for long trips, and electrical outlets in garages would provide the power for short commutes. (Eventually, charging stations could be installed for city dwellers.) And plenty of electricity is available, particularly overnight. According to a study from the Pacific Northwest National Laboratory, there’s already enough excess generating capacity at night to charge 84 percent of the cars, pickups, and SUVs on the road today, if they were all suddenly converted into plug-in hybrids.