By now we’re all aware that the environmental impact of cars and trucks goes well beyond the emissions produced during operation. There is the energy used to produce and dispose of the vehicles and their components, for example, and the cost of getting the fuel for the vehicles out of the ground and into the tank. The impact of making nickel metal hydride batteries for hybrid and electric vehicles (EVs) was the center-piece of a controversial study published by CNW several years ago. That study claimed that a Hummer H2 had less of an environmental impact than a Toyota Prius in large part because of pollution resulting from nickel mining in Canada.
A new life cycle study conducted by the Swiss Federal Laboratories for Materials Science and Technology (EMPA) has come to a very different conclusion after evaluating the latest lithium-ion batteries developed specifically for automotive applications. These new batteries only account for about 15 percent of the total impact of an electric vehicle over its lifespan when the mining, refining, manufacturing and disposal are factored in. The vast majority of the vehicle’s overall energy footprint results from actual operation of the vehicle; in the case of an EV, this mostly means how much it takes to charge the battery.
If an EV is charged by the typical mix of nuclear, coal and hydroelectric power found in Europe, an internal combustion vehicle would need to achieve between 59 and 78 miles per gallon to have a comparable impact. There are several diesel-powered small cars available in Europe that already hit those kinds of numbers, including the Ford Fiesta ecoNetic and Volkswagen Polo Bluemotion. If the electricity production mix shifts more toward coal, the energy balance gets significantly worse for a plug-in car, while an generation profile with a larger percentage of hydro or other renewable sources clearly improves the picture in the EV’s favor. Still, a baseline target of 59 to 78 mpg is a good one for liquid-fuel vehicle fans to consider.
AutoblogGreen
=> Study: Modern li-ion batteries have little effect on life cycle impact of electric cars.
No comments:
Post a Comment