Are Electric Cars Really That Dirty?

By Bill Moore

Posted: 16 Feb 2012

"Electric vehicles are only as good or bad as the power sector that recharges them."

- Assistant professor Christopher Cherry, University of Tennessee, Knoxville

I have to admit that when I saw the tsunami of headlines screaming how bad electric cars are, how much dirtier they are than gasoline cars, it got my dander up. To use digital shorthand, I thought WTF? Electric cars are dirtier than gasoline? On what planet?

I wanted to hastily scribble out a scathing epistle about all the flaws in the study that appears in the journal Environmental Science and Technology, co-authored by researchers at the University of Tennessee, Knoxville, the University of Minnesota and Tsinghau University in Beijing. Like one commentator on Time magazine's web site, I wondered how much dirty coal and oil money funded this study? Of course, I hadn't actually read the study at that point, only seen media stories about it.

So, I decided to keep my powder dry and see if I could get the lead author, Chris Cherry to talk to me about it. I emailed him and he kindly replied and we agreed to do a podcast interview this morning, February 16, 2012. He also provided me a copy of the paper, which I read bright and early this morning while doing my daily 2-mile hike on the treadmill in the basement.

That moment of temperance paid off, as did "going to the horse's mouth." It turns out that Cherry and I aren't all that far apart on our views of electric vehicles; both the two and the four-wheeled kind. As you'll hear from the podcast, the real purpose of the paper wasn't to denigrate electric vehicles, but to study what impact they might have on the health of the people of China, where the uptake of electric bicycles and scooters has been phenomenal with an average market growth over the last decade of a whopping 85% annually. There now are 100 million electric two-wheelers running around China every day, consuming an estimated, according to Cherry, 2-3% of the nation's daily electric power production. That translates into an estimated 2 billion kilometers a day traveled on electric power.

In fact, what Cherry and his colleagues in Minnesota and Beijing discovered is that compared to gasoline and diesel cars, diesel buses, and electric cars, e-bikes are not only the most efficient, but also have the least environmental impact and health consequences of the five modes of travel they compared. They estimate that should a Chinese city decide to impose a ban on e-bikes, which some have considered doing given their explosive growth, the resultant mortality rate would climb from an estimated 2 deaths per 100,000 population to 12 deaths per 100,000, largely because 70% of former e-bike commuters would resort to again riding diesel buses, virtually all of which have no modern emission controls.

As to the question of the environmental impact of electric cars compared to gasoline, the issue really isn't how dirty electric cars are, they aren't because they produce zero local emissions, compared with ICE-age models. The problem is how dirty China's electric power grid is. EVs displace their tailpipes from local city streets to distant rural villages in the wind shadow of a coal-fired power plant, in effect, the report points out, shifting a significant portion of environmental responsibility from the people who benefit from electric vehicles to those who may benefit the least. So, in that respect, it's not just a matter of local air pollution, but also one of environmental justice.

As became obvious during my 30-minute discussion with Professor Cherry, he isn't at all opposed to electric vehicles. Not only did he write his dissertation on electric bicycles but also he spearheaded the creation of one of America's first electric bikeshare networks on the campus of the University of Tennessee Knoxville. His problem with electric cars is how they are recharged, as the quote at the top of the page indicates. He makes the point that despite how clean an gasoline car in China is today, it will, over time, only get dirtier as its engine, emission control equipment, exhaust system, and seals begin to deteriorate. What the media is missing, he stressed to me, is that over the same course of time, those electric cars will only get cleaner as China -- and other nations -- clean up their electric power grids, demolishing old, highly-polluting, thermoelectric plants and replacing them with cleaner generation.

And while he didn't specifically state this, I feel comfortable in asserting that such replacements have to happen in China and elsewhere for simple economic reasons: old plants are economically inefficient. Like replacing an old, broken down gas guzzlers, they too have to taken out of service, dismantled and recycled. What replaces them will almost always be far more efficient and produce less emissions per unit of power produced.

So, China's problem -- and by extension America, Europe, and elsewhere -- isn't "dirty electric cars," but our dirty -- and thirsty -- thermoelectric power plants. That's the real message of "Electric Vehicles in China: Emissions and Health Impacts." Clean up the plants and the cars, buses and yes, electric bikes, automatically get cleaner. Rush Limbaugh can't say that about his Mercedes Maybach, which the EPA reports gets a combined fuel economy of 12 mpg.

Incidentally, Cherry's research concluded that in terms of CO2 emission, an electric car in Beijing will indirectly generate the same emissions as a gasoline car that gets 26 mpg. That's more than twice the fuel economy of Rush's Maybach, so what's that tell you?


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