A research team composed of members from the University of Minnesota and NREL recently evaluated the overall impact of different fuels we use in our automobiles, or light-duty transportation as the study authors call them, on the environment. They compared various conventional and renewable energy sources – from using corn ethanol as biofuel, coal-based electricity in EVs, wind water and solar power for EVs, and gasoline hybrid vehicles, among many options.
Their study is different in that it considers not only the greenhouse gas (GHG) emissions of driving our cars, but the impact on air quality of power generation. In fact, they say that GHG emissions are not the biggest environmental impact of using vehicles, but rather externalities such as air pollution and health impacts, among other things.
Based on their analysis, driving EVs can result in higher concentrations of particulate matter in the air than using gasoline and diesel cars. This is true if coal is burned in large quantities to generate the electricity we’ll need to drive our EVs. What’s more, whereas particulate matter only goes up only in selected cities in the US when using fossil fueled cars, if we use our coal-heavy energy mix for our EV’s the particulates levels will shoot up in much of the continental US from the Eastern seaboard states from Maine to Florida and all the way to the mountain states from Montana to Utah, as can be seen in the maps to the right.
Another finding of the study is that the use of corn, either as ethanol biofuel or as fuel for power plants for EVs, also results in bad air quality even if they reduce GHGs. The use of corn stover as biomass power generation to drive electric vehicles is waaay worse than using natural gas, and will contribute to smog in the states surrounding the Great Lakes.
Not surprising is the finding that the use of wind, wave and solar (WWS) power to generate power to drive EVs has the best impact on air quality and GHGs. What’s unexpected, probably, is the finding that using EVs driven by natural gas derived electricity has the second best impact on air quality as well as GHG emission reduction, followed by gasoline hybrids. Biofuel from corn stover can help reduce GHG emissions significantly but it also results in a net deterioration in air quality. Using bioethanol from corn grain has a huge impact on air quality which the study says outweighs its GHG reduction.
So this means that humanity may be better off if we drive Priuses and other hybrids instead of EVs until such time that we phase out coal from the power mix.
Still, both are better than Santa’s sleigh until he can control his reindeer’s flatulence. Hohoho!