By Max Baumhefner and Cecilia Springer, August 14, 2013
Uncovering a fraud is uniquely satisfying, which is perhaps why news
outlets continue to provide electric car deniers with a platform to
proclaim they aren’t as green as they appear. But close examination
reveals the latest round of skeptics to be lacking in substance.
Numerous peer-reviewed articles have reached the same conclusion:
From cradle to grave, electric cars are the cleanest vehicles on the
road today. And unlike cars that rely on oil, the production of which is
only getting dirtier over time, the environmental benefits of electric
cars will continue to improve as old coal plants are replaced with
cleaner sources and manufacturing becomes more efficient as it scales up
to meet growing consumer demand.
“Did you account for the pollution from the electricity it takes to power the vehicles?”
This question has been asked and answered.
Using today’s average American electricity mix of natural gas, coal,
nuclear, hydro, wind, geothermal, and solar, an electric car emits half
the amount of harmful carbon pollution per mile as the average new
vehicle. In states with cleaner mixes, such as California, it’s only a
quarter as much. To find out how clean your electric car would be today, plug your zip code into the EPA’s “Beyond Tailpipe Emissions Calculator.” Those benefits will only improve as the electric grid becomes cleaner over time.
Before the Natural Resources Defense Council began advocating for
vehicle electrification, we did our own homework, publishing a two-volume report
in partnership with the Electric Power Research Institute. The work
took almost two years and concluded that a long-term shift to the use of
electricity as a transportation fuel provides substantial reductions in
carbon pollution and air quality benefits.
It’s essential to take a long view when examining vehicle
electrification, because the electric grid doesn’t stand still. Since
the time we published that report, the EPA has adopted power plant
standards for mercury and other air toxics, ozone-forming emissions,
fine particulate pollution, soot, and coal ash; proposed standards for
greenhouse gases from new power plants; and has been directed by the
president to adopt greenhouse gas standards for existing plants.
Meanwhile, 29 states have adopted renewable energy targets to reduce
emissions. Driving on renewable electricity is virtually emissions-free.
“Did you account for the resources it takes to build the cars?”
Producing an electric car today requires more resources than
producing a conventional vehicle, generally due to the large batteries.
However, comparing the efficiency of relatively nascent and small-scale
electric vehicle manufacturing to the efficiency of conventional
automobile production, which has benefited from more than a century of
learning-by-doing, is misleading. Automakers are racing to save money
and materials through recycling and more efficient production. Those who
win the race will win the market.
Even with today’s technology, on a lifecycle basis, the electric car
is still the cleanest option available. Higher emissions from
manufacturing are more than offset by the substantial benefits of
driving on electricity. We examined six peer-reviewed academic studies
and found that in every case, electric vehicles win by a substantial
margin, with estimates ranging from 28 to 53 percent lower
cradle-to-grave emissions than conventional vehicles today.
Opponents often rely upon the original version of a Norwegian study,
which has much higher estimates of emissions associated with the
production of electric cars. Those skeptics generally cherry-pick from
the original version of that article, and ignore the fact it was corrected
post-publication, resulting in its estimate of the comparative
emissions benefit rising from 22 percent to 28 percent. In other words,
even the source relied upon by skeptics shows a substantial lifecycle
advantage for electric cars. The Norwegian study finds the lowest
benefit relative to the other articles examined partially because it
includes an estimate of emissions associated with the disposal of
advanced battery materials that is higher than other studies, which
brings us to the next question:
“What about mining and disposing of the materials needed to make the batteries?”
First off, there is no shortage of the materials needed to make advanced vehicle batteries. A recent article in the Journal of Industrial Ecology
concludes, “even with a rapid and widespread adoption of electric
vehicles powered by lithium-ion batteries, lithium resources are
sufficient to support demand until at least the end of this century.” Another analysis of
the trade constraints associated with the global lithium market came to
a similar conclusion, and noted that even a “five-fold increase of
lithium price would not impact the price of battery packs.” Furthermore,
companies like Simbol Materials are already finding innovative ways to
acquire lithium by harvesting materials from the brine of geothermal
power plants — no mining required.
Secondly, advanced vehicle batteries are unlikely to be simply thrown
away; they’re too valuable. Even once they’re no longer suitable for
automotive use, they retain about 80 percent of their capacity and can
be re-purposed to provide grid energy storage to facilitate the
integration of variable renewable resources, such as wind and solar.
Automotive batteries can also be repurposed to support the electrical
grid at the neighborhood level, preventing the need to invest in costly
distribution system equipment. Pacific Gas & Electric plans to use
money saved through the strategic deployment of used battery packs in
neighborhoods throughout Northern and Central California to provide
electric car drivers with rebates to reduce the purchase price of new
Finally, those batteries that aren’t repurposed will likely be
recycled. Conventional vehicle manufacturing is one of the most
efficient industries in the world — around 95 percent of vehicle parts
are recycled, reducing the energy needed to make more parts. It is worth
noting that conventional lead-acid car batteries are consistently the
most recycled product for which the EPA provides data [PDF], with a recycling rate of 96 percent. Advanced battery recycling could cut associated emissions in half, according to a 2012 study from researchers at Argonne National Laboratory. Companies are already investing in such technologies.
In summary, a sustained and serious examination of the
cradle-to-grave impacts of electric cars reveals they are the cleanest
option available today, and that the environmental benefits of vehicle
electrification will only increase over time. That’s not only good news
for the eco-conscious, but for any consumer interested in driving on a
cleaner fuel at a price equivalent to buck-a-gallon gasoline.