The Tough Calculus of EV carbon emissions. “A growing body of research points to the likelihood that widespread replacement of conventional cars with EVs would likely have a relatively small impact on global emissions. And it’s even possible that the outcome would increase emissions.”
“…Uncertainties in the embodied energy begin with the ore grade, or share of rock that contains each target mineral. Ore grades can range from a few percent to as little as 0.1 percent depending on the mineral, the mine, and [overburden]. Using today’s averages, the quantity of ore mined—necessarily using energy-intensive heavy equipment—for one single EV battery is about: 10 tons of lithium brines to get to the 30 pounds of lithium; 30 tons of ore to get 60 pounds of cobalt; 5 tons for the 130 pounds of nickel; 6 tons for the 90 pounds of copper; and about one ton of ore for the 190 pounds of graphite.
Then, one must add to that tonnage the “over-burden,” the amount of earth that’s first removed in order to access the mineral-bearing ore. That quantity also varies widely, depending on ore type and geology, typically from about three to seven tons excavated to access one ton of ore. Putting all the factors together, fabricating a single half-ton EV battery can entail digging up and moving a total of about 250 tons of earth. After that, an aggregate total of roughly 50 tons of ore are transported and processed to separate out the targeted minerals.”
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“Similarly problematic, one finds forecasts of future emissions savings often explicitly assume that the future battery supply chain will be located in the country where the EVs operate. One widely cited analysis assumed aluminum demand for U.S. EVs would be met by domestic smelters and powered mainly from hydro dams. While that may be theoretically possible, it doesn’t reflect reality. The United States, for example, produces just 6% of global aluminum. If one assumes instead the industrial processes are located in Asia, the calculated lifecycle emissions are 150% higher.”