Hey, electric-car drivers: Before you get all smug about your green cred, ask yourselves a couple of key questions:
Where does the power to juice up your car originate? And what impact does this have on the environment and human health?
University of Minnesota researchers looked into this, and their findings are in this week.
Electric cars that get their power from renewable energy sources — like wind or solar — could reduce deaths resulting from air pollution by 80 percent compared with cars that get electricity from other sources such as coal or ethanol.
In other words, you could be polluting, albeit indirectly, even if your eco-chic hatchback is of a no-emissions electrical variety.
The study, appearing today in the Proceedings of the National Academy of Sciences, also compares the environmental impact of gasoline cars compared with those using electricity derived from renewable energy.
Using the latter kind of vehicle could reduce the number of deaths resulting from air pollution by 70 percent, according to the study’s authors, Chris Tessum and Julian Marshall of the university’s College of Science and Engineering and Jason Hill of the College of Food, Agricultural and Natural Resource Sciences.
Air pollution is the greatest environmental health hazard in the United States, killing an estimated 100,000 people a year, according to the researchers. Air pollution increases rates of heart attack, stroke and respiratory ailments.
The researchers were curious to see how concentrations of two important pollutants — particulate matter and ground-level ozone — fluctuate depending on what kind of a car is used and how that vehicle obtained its power for propulsion.
They considered 10 alternatives to traditional gasoline vehicles.
The findings are stark: The health impact of an electric car powered by renewable energy is about a third that of driving a gasoline-powered car, Hill said.
But using an electric car powered by coal is four times worse than using a gas vehicle.
Also, corn-derived ethanol is much worse for air quality than gasoline, Hill added.
“Every gallon of gasoline you burn has 50 percent of (adverse) impact on others,” Hill said. “Ethanol is twice as bad at $1. And coal has about $2 of external damage.”
On the other hand, only 15 cents of external damage is produced by electric vehicles with energy derived from renewable sources, he said.
“The fact that you have such a potential swing in benefits was pretty amazing to us,” Hill said. Going in, “we were pretty sure there would be an impact, but we were surprised just how big that impact could be.”
The researchers looked not only at car pollution but also at emissions generated during production of such fuels. Notably, with ethanol, air pollution is released from tractors on farms, from soils after fertilizers are spread and to supply energy for the fermenting and distilling corn into ethanol.
The takeaway is clear, said Hill: “Invest heavily in clean energy and use electric vehicles” that tap into that renewable energy.
Source: http://www.twincities.com/technology/ci_27140844/u-study-finds-electric-cars-powered-by-renewables?source=rss
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