A full 12 years after Toyota sold its first Prius in the United States and came to pretty much dominate the U.S. market for environmentally friendly cars, drivers in America will have two more options for green transportation: Chevrolet's Volt and Nissan's Leaf.
It all comes down to carbon emissions, and even though electric vehicles spew zero emissions, they aren't necessarily carbon neutral. So that begs the question, are they better for the environment than ones powered by fossil fuels?
"Zero-tailpipe emissions unfortunately don't necessarily mean zero emissions," says Dennis Ruez Jr., the environmental studies department chair at the University of Illinois at Springfield.
Carbon-neutrality refers to emissions of carbon dioxide that are released during any point in the life span of the vehicle, from the earth-moving machines used to mining the lithium for the car's batteries, to the plant where the car is built, to the power plant that feeds the electrical source the car is ultimately plugged into. None of those can emit carbon dioxide. If any do, the electric vehicle isn't carbon-neutral.
Attaining complete carbon neutrality is virtually impossible, or at least so unattainable it's akin to holding out for a vehicle that runs on cold fusion. Instead, researchers are chipping away at problems in smaller sizes, with a specific focus on the power plant -- the source of most EV emissions.
"The well-known issue here is the source of the electricity," says Ruez. "If the electricity is from a coal- or gas-fired power plant, then there are still carbon emissions from that vehicle's use."
Ruez's comments were featured in a July 30, 2010, article by Discovery News.
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