Today’s hybrid cars may save fuel, but their battery power ultimately comes from burning gasoline. New plug-in models will be greener.
 | Plugging in to hybrid powerThe next generation of hybrid cars can be charged simply by plugging into a normal wall socket. (Photo: Reuters) |
Hybrid engines combine a normal internal combustion engine with a battery-powered electric motor. Energy generated by running the engine and operating the brakes charges the battery. The electric motor can then be used instead of the engine to drive at low speeds, for braking, and for extra acceleration at high speeds, thereby saving fuel. Hybrids also save energy by shutting off the engine when the car is stationary, making them particularly useful for short, stop-go-stop urban journeys.
Hybrid engines have been put into cars, buses, and even motorcycles. There are about 1.5 million hybrids on the world’s roads today, with the Toyota Prius, first released in 1997, leading the way with over one million sales. Hybrid buses tested in New York City saved 10 percent in fuel consumption. International shipper FedEx claims a 57-percent fuel economy improvement for its diesel hybrid delivery vehicles. Meanwhile, Honda has developed a 50cc hybrid scooter that boasts a one-third reduction in fuel use.
Hybrids may reduce dependence on fossil fuels, but they rely on the gas engine to generate the energy for the battery. The next generation of hybrids, by contrast, will be able to get electricity from the grid. Plug-in hybrids are an evolution towards all-electric vehicles. General Motors’ answer to the Prius, the Chevy Volt, uses the gas engine not to run the wheels directly, but as a back-up generator for a battery that can be charged overnight from an ordinary power socket.
 | Green CarsCars symbolize freedom, individuality, and environmental destruction. Click on the image to see how a new breed of cars might offer more climate-friendly mobility. |
Like laptop computers and mobile phones, plug-in hybrids use lithium-ion batteries, which offer greater power and performance than the nickel-metal-hydride battery in today’s Prius. GM says the Volt, due to go into production in 2010, will go 80 kilometers on one electric charge. The company also claims the Volt will cost about 1.2 cents a kilometer to operate, compared to the 7.5-cent expense of a conventional car.
But with a price tag estimated at between 30,000 and 50,000 dollars, the Volt will not come cheap. That’s because its lithium-ion battery alone costs about 10,000 dollars. It also weighs 180 kilograms and is just under two meters long, begging the question: where will the luggage go?
Advanced hybrids will therefore be prohibitively expensive to produce until they become more popular and production levels increase. GM will only produce 10,000 Volts in its first year. Nevertheless, both GM and Toyota expect to be producing one million hybrid cars a year by 2020. Other major manufacturers also have ambitious plans.
The U.S. Electric Power Research Institute estimates that hybrids with a 30-kilometer electric-only range could substitute electricity for gasoline for 30–40 percent of all kilometers driven in the U.S. The average American commutes 29 kilometers a day to work. If a mass market can be created for these vehicles, the potential to reduce road transport’s thirst for gas is immense.
editor: James Tulloch
publishing date: September 29, 2008
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