By Max Baumhefner, Sustainable Energy Fellow, San Francisco, and Cecilia Springer, associate at Climate Advisers, where she manages projects on transportation and sustainable supply chains.
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 NRDC 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, twenty-nine 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 crade-to-grave emissions than conventional vehicles today.
Opponents often rely upon the original version of a Norwegian study (Hawkins 2012), 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 re-purposed 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 electric cars.
Finally, those batteries that aren’t re-purposed 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, 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. For more, see Real Oil Independence: Buck-a-Gallon Electricity for Life.