I’m excited to introduce our newest analysis on electric cars, titled: Cleaner Cars from Cradle to Grave: How Electric Cars Beat Gasoline Cars in Lifetime Global Warming Emissions. After years of mixed messages on whether electric vehicles (EVs) really are better for the environment, we’re pleased to provide one of the most comprehensive answers to date (sneak peek: yes, they’re cleaner by 50 percent). Here’s what we’ve found…
- From cradle to grave, battery-electric vehicles are cleaner. On average, battery electric vehicles (BEVs) representative of those sold today produce less than half the global warming emissions of comparable gasoline-powered vehicles, even when the higher emissions associated with BEV manufacturing are taken into consideration. Based on modeling of the two most popular BEVs available today and the regions where they are currently being sold, excess manufacturing emissions are offset within 6 to 16 months of driving.
- EVs are now driving cleaner than ever before. Driving an average EV results in lower global warming emissions than driving a gasoline car that gets 50 miles per gallon (MPG) in regions covering two-thirds of the U.S. population, up from 45 percent in our 2012 report. Based on where EVs are being sold in the United States today, the average EV driving on electricity produces global warming emissions equal to a gasoline vehicle with a 68 MPG fuel economy rating.
- EVs will become even cleaner as more electricity is generated by renewable sources of energy. In a grid composed of 80 percent renewable electricity, manufacturing a BEV will result in an over 25 percent reduction in emissions from manufacturing and an 84 percent reduction in emissions from driving—for an overall reduction of more than 60 percent (compared with a BEV manufactured and driven today).
Global warming emissions from driving
Although a BEV has no tailpipe emissions, the total global warming emissions from operating it are not insignificant; they depend on the sources of the electricity that charge the vehicle’s batteries and on the efficiency of the vehicle. We estimated the global warming emissions from electricity consumption in the 26 “grid regions” of the United States—representing the group of power plants that together serve as each region’s primary source of electricity—and we rated each region based on how charging and using an EV there compares with driving a gasoline vehicle.
Emissions from operating electric vehicles are likely to keep falling, as national data from 2013 to 2015 show a declining percentage of electricity generated by coal power and an increase in renewable resources such as wind and solar. Additionally, the Clean Power Plan finalized by the U.S. Environmental Protection Agency (EPA) in 2015 offers opportunities for even greater progress, as states must collectively cut their power-sector carbon emissions 32 percent by 2030 (based on 2005 levels). Meanwhile, many EV owners are pairing electric vehicle purchases with home investments in solar energy. With increasing levels of renewable electricity coming onto the grid, with carbon standards for fossil-fuel power plants beginning to be implemented, and with continued improvements in vehicle technologies, the emissions-reduction benefits of EVs will continue to grow.
Global warming emissions from manufacturing
Global warming emissions occur when manufacturing any vehicle, regardless of its power source, but BEV production results in higher emissions than the making of gasoline cars—mostly due to the materials and fabrication of the BEV lithium-ion battery. Under the average U.S. electricity grid mix, we found that producing a midsize, midrange (84 miles per charge) BEV similar to a Nissan LEAF typically adds a little over 1 ton of global warming emissions to the total manufacturing emissions, resulting in 15 percent greater emissions than in manufacturing a similar gasoline vehicle.
However, replacing gasoline use with electricity reduces overall emissions by 51 percent over the life of the car. A full-size long-range (265 miles per charge) BEV similar to a Tesla Model S, with its larger battery, adds about six tons of emissions, which increases manufacturing emissions by 68 percent over the gasoline version. But this electric vehicle results in 53 percent lower overall emissions compared with a similar gasoline vehicle (see Figure below).
In other words, the extra emissions associated with electric vehicle production are rapidly negated by reduced emissions from driving. Comparing an average midsize midrange BEV with an average midsize gasoline-powered car, it takes just 4,900 miles of driving to “pay back”—i.e., offset—the extra global warming emissions from producing the BEV. Similarly, it takes 19,000 miles with the full-size long-range BEV compared with a similar gasoline car. Based on typical usages of these vehicles, this amounts to about six months’ driving for the midsize midrange BEV and 16 months for the full-size long-range BEV.
Meanwhile, the global warming emissions of manufacturing BEVs are falling as automakers gain experience and improve production efficiency. With a focus on clean manufacturing, emissions could fall even more. There are many ways in which the EV industry might reduce these manufacturing-related emissions, including:
- Advances in manufacturing efficiency and in the recycling or reuse of lithium-ion batteries;
- The use of alternative battery chemistries that require less energy-intensive materials; and
- The use of renewable energy to power manufacturers’ and suppliers’ facilities.
We also made the below to summarize the results, and you can use our interactive tool to explore emissions from driving an electric car in your area. Please share to get the word out that electric vehicles are clean and getting cleaner!
If you have more questions about the report join us on Monday November 16th when my colleague Dave and I will be hosting an Ask Me Anything (AMA) on Reddit.
So there you have it. Electric cars are clean and getting cleaner, even on a life cycle basis
Posted in: Vehicles
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