A recent column by Leo Hickman in The Guardian set off a wave of debate over the true merit of electric vehicles ( EVs) compared to internal combustion engine vehicles (EVs). Hickman used a study from the Norwegian University of Science and Technology (NTNU) called Comparative Environmental Life Cycle Assessment of Conventional and Electric Vehicles that explored a variety of factors involved in the lifecycle of the car – from materials used to vehicle emissions to the source of energy moving the metal – as a starting point. The problem, as we'll see, is that the study uses some dubious assumptions to badmouth EVs.

The study sends something of a warning signal in its finding that the production and lifecycle of EVs makes them not as great as proponents have been stating. Specifically, the technology is more energy-demanding during production and can actually bring more CO2 emissions than conventional vehicles.

The study doesn't outright condemn EVs. At its conclusion, the report authors said that the production phase of EVs is more "environmentally intensive," but it does bring with it substantial overall improvements for GPW (global warming potential), TAP (terrestrial acidification potential) and other positive impacts if powered by appropriate energy sources. That being said, it's counterproductive to push for EVs in regions where electricity is generated by oil, coal, or lignite (coal in its early stage) combustion.

As for recycling of the EVs, Guillaume Majeau-Bettez, one of the paper's authors, wrote,
"Hopefully, subsequent 'waves' of electric cars would be made with a higher fraction of recycled metal (ecars made from ecars, cradle-to-cradle...), but the industry is not there yet."

Several readers left comments on Hickman's article saying the report overstated the downside of EVs. And criticism is growing. Fully Charged's Robert Llewellyn wrote an important article drawing connections between the report authors and the oil industry (hint: there are many). He also points out some egregious assumptions the authors make, for example, "Their calculations were for a 1,000 kg motor, the motor in the Nissan Leaf weighs 53kg. As you can imagine, an error of this magnitude could skew the figures rather badly. "

Earlier this year, the Union of Concerned Scientists (UCS) released a report analyzing emissions and costs for both EVs and gasoline-powered vehicles. The study provided a well-to-wheel (drilling, refining, burning for gas and mining coal, making electricity for EVs) comparison and found greater benefits coming from EV technology than that determined by NTNU. In a new blog post directly analyzing the NTNU article, UCS' senior engineer of clean vehicles, Don Anair, references the earlier work and then writes:

The numbers show that even in the worst case, on the dirtiest grid and assuming EV vehicle production creates twice the number of global warming emissions as a gasoline vehicle, an EV still has a slight (6%) emission advantage compared to the average new compact.

It's well worth the read. In fact, any time there's a study purporting to decimate arguments against plug-in vehicles, it's worth investigating the back story.

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