How Electric Cars Trump Gasoline

Guest Blog | November 20, 2015 | Clean Transportation, Electric Vehicles

With the Southeast’s heavy reliance on coal power, the emissions benefit of electric vehicles (EVs) has been brought into question in recent years. Not only that, but what about the associated emissions from manufacturing and disposing of EV batteries? In the Union of Concerned Scientists’ (UCS) new report, Cleaner Cars from Cradle to Grave, they answer those questions – providing both an update to their 2012 State of Charge report and analysis of the overall lifecycle emissions from both gasoline vehicles and EVs. The new report also includes a handy new feature offering zip code searches to find out how clean driving an EV is wherever you live or charge.

They found that the production and the manufacturing of batteries for an EV produces significant global warming emissions, but when you compare the overall emissions over its entire lifecycle to that of gasoline cars, EVs are more than 50% cleaner than comparable gasoline vehicles. Lifecycle global warming emissions examined in this report include everything from the raw materials to make the cars and gasoline (extraction, refining, delivery) to manufacturing, driving, disposal and/or recycling of parts.

Comparatively, the largest source of emissions from a gasoline vehicle is its fuel consumption (from fuel production to burning it in its engine), and the largest source from an EV is in the battery manufacturing and electricity consumption. Global warming emissions from manufacturing an EV’s battery is significant, but not all EVs are created equal. For an EV that has a battery with a ~84 mile range, the process results in 15% more emissions than manufacturing a comparable gasoline vehicle. And, that number jumps to 68% more for a longer range (bigger battery – 85 kwh) EV.

But the good news is that UCS found that the additional manufacturing emissions from EVs, mostly from producing

Source: Union of Concerned Scientists, Cleaner Cars from Cradle to Grave, p.3

the lithium-ion battery, are offset very quickly by the lower emissions from driving the EV compared to a similar gasoline vehicle — only 6 months to offset the manufacturing emissions of a 84-mile range battery electric vehicle, and 16 months to offset the manufacturing emissions of a 265-mile range battery electric vehicle (due to the bigger battery) based on the latest available information on regional electricity grid emissions.

What UCS also notes in their report is that those emissions will vary depending on the energy used in manufacturing. For Tesla, for example, they intend to produce their batteries with 100% renewable energy. Combining renewable energy both in production and use, EVs offer a huge opportunity for furthering the emissions benefits of driving them.

Emissions from driving an EV are getting cleaner. For this project, UCS also updated their 2012 State of Charge Report, which we previously posted here.  They found that the average EV in the U.S produces global warming emissions equivalent to driving a 68 mpg gasoline car (based on the average mix of electricity sources). In the Southeast, historically with one of the “dirtiest” grids in the country, the emissions from driving and charging a Nissan LEAF today is comparable to those from driving an gasoline vehicle that gets 51 mpg – up from 46 mpg just a few years ago. This is better than most other gasoline vehicles on the road today. Since the 2012 report, most of the Southeast has improved its ranking in the UCS analysis transitioning from a “better” region for driving an EV to an area ranked as “best.” Why?  For one, the electricity grid is getting cleaner. Renewable energy development, like solar and wind, has been growing while coal, a significant source of global warming emissions, is declining. And, when exclusively powered by a renewable source of energy, like solar or wind, an EV will achieve even greater global warming benefits. The overall efficiency of EVs is also

A Nissan LEAF combined with solar power provide significant emissions benefits. Photo credit: Jennifer Weiss

improving – we are getting more energy out of the same battery and there have been improvements in aerodynamics, heaters, braking, and more from just three years ago. The benefits will be optimized as well as more and more people combine solar and EV charging. See how EVs compare across the U.S based on the current energy mix here.

So, what about the old EV batteries? As the report points out, many or most EV manufacturers offer 100,000 mile warranties on their lithium-ion batteries, therefore it is assumed that batteries will likely perform well for at least that distance. However, temperature and weather, as well as usage, can affect the battery’s useful life with a loss of range over time. The analysis found that the disassembly and recycling and/or disposal of an EV’s battery should be expected to grow as EVs become more popular, but even at today’s recycling rates makes up a small part of the lifecycle emissions of EVs. The information cited in the report also notes that vehicle disposal rates and practices are expected to be similar for EVs and gasoline vehicles, accounting for “less than 5 percent” of total manufacturing emissions.

A clearer picture of the possible differences between gasoline vehicles and EVs can be expected as more EVs are retired. As for battery recycling, UCS, erring on the conservative side, selected to assume no emissions savings from the recycling or reuse of the lithium-ion battery, but also applied industry recycling standards in determining the total lifecycle emissions from EVs. Additional improvement in the emissions profile from batteries can be expected with advances in its fabrication and recycling and greater use of alternative materials and designs. For more information on battery resources, check out Chapter 2 of the report.

In the UCS report, they also call for policy changes including increasing renewable energy generation through the Clean Power Plan, establishing a national renewable energy standard, increased funding for battery research and recycling and direct consumer investment in renewable energy. Given some of the recent state roll-backs of EV incentives, it’s also key that the federal EV tax credit and charging infrastructure tax incentives be protected and/or restored. Incentives are proven to be effective tools in bridging nascent industries into successful ones.

Bottom line: With major car manufacturing incorporating battery electric vehicles (i.e. all electric) and/or plug in hybrid electric (both electric and gasoline) in their line ups, it’s important to understand the lifecycle impacts of these vehicles and where to focus on further emissions reductions. Unlike gasoline vehicles that get dirtier over time, EVs get cleaner every year. With increasing improved efficiency, a cleaner grid and strong policies for renewable energy and EVs, EVs will lead us further in to a clean energy future. For the full report, including the methodology, check out Cleaner Cars from Cradle to Grave here.

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