Published March 9, 2006Dear EarthTalk: As I understand it, hybrid cars make use of an electric motor that never needs to be plugged in. But whats up with the proposed plug-in hybrids Ive been hearing about? Jen Seminara, Omaha, NE
The mass-market gasoline-electric hybrids made by Toyota, Honda and others make use of an electric engine right under the hood next to the gas engine. That electric motor creates fuel economy by kicking into use during idling, backing up, slow traffic, and to maintain speed after the gas engine has been employed for acceleration. The car doesnt need to be plugged in because the on-board electric battery is constantly being charged by the gas engine and by the motion of the wheels and the brakes.
The Advantages of Plug-in Hybrid Cars
The so-called plug-in hybrids, now in prototype stages of development, take this technology a step further. By adding the ability to charge up from a standard household outlet, typically overnight, such cars relegate the gas engine to back-up status and instead let the electric motor do most of the work.
Proponents claim that such gas-optional carsif you dont take long trips you can rely entirely on the electric motorcan be twice as fuel efficient as hybrids, which already get double the gas mileage of traditional vehicles. Additionally, they say, powering up plug-in hybrids with wall sockets results in far less pollution (from the power plants providing the electricity) than an equivalent gasoline-powered car spews out its tailpipe. Meanwhile, plug-in hybrids recharged from rooftop solar power systems might approach being the worlds first mass-market zero emission vehicles, requiring no power from the grid at all.
Will Drivers Accept Plug-in Hybrid Cars?
Convincing a skeptical American public that plug-in hybrids are the way of the future is the challenge of a loose network of advocacy groups led by the California Cars Initiative (CalCars). Indeed, the experimental electric vehicles of a decade ago and older required recharging every 25-50 miles, rendering them useless for anything but short trips. The new breed of plug-in hybrids solves this problem by employing much more sophisticated battery technology while still keeping the insurance of gasoline (and a gas engine) on-board.
Its like having a second small fuel tank that you always use first--only you fill this tank at home with electricity at an equivalent cost of under $1/gallon, reports the CalCars website. The organization goes on to explain that with gas prices at $3/gallon, operating traditional cars costs eight to 20 cents per mile, while plug-in hybrids used for all-electric local travel and commuting would cost only two to four cents per mile.
The Status of Plug-in Hybrid Technology
CalCars is lobbying the worlds major automakers to introduce plug-in options on future hybrid models, and the organization has built showcase examples that achieve 100 miles per gallon using Toyotas Prius. Meanwhile, a growing list of state and local governments say they would seriously consider converting their fleets to plug-in hybrids if such vehicles became available.
The website HybridCars.com reports that DaimlerChrysler has built a handful of prototypes based on its 15-passenger Mercedes-Benz Sprinter van. And analysts believe Toyota already has the technology in place, but may be waiting to gauge consumer demand before making any production commitments. Only timewith a little guidance from the price of gasolinewill tell.
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