“But you’re still using electricity from the grid!” drunk Uncle Carl says at the family gathering he is invited to once a year. “And that electricity comes from coal.”
On the whole, the United States produces ~30% of its electricity from coal. Some states make considerably less electricity from coal. California makes almost no electricity from coal. Idaho makes almost no electricity from coal. You get the idea.
The thing is that even if my Nissan Leaf is using electricity from the grid it is still more efficient on a per mile basis versus almost any other car or truck on the road. It is more efficient in terms of carbon emissions per mile and cost per mile in dollar terms. Let’s see how that breaks down.
A gallon of gasoline, when burned, produces approximately 20 pounds of carbon dioxide. In 2016 the fuel economy of new cars and trucks in the United States reached 24.7 miles per gallon. Therefore, on a per mile basis the average new car in the United States emits 0.81 pounds of carbon dioxide.
A kilowatt hour of electricity has a carbon intensity of approximately 1 pound. This figure obviously differs depending upon your utility, grid operator, locale, etc. but it works as an average for the United States. Over the course of the last couple of weeks I have averages 4.2 miles per kWh in my Nissan Leaf, which is probably low since I have been forced to use the relatively inefficient resistive heater. Therefore, my EV “emits” 0.24 pounds of carbon dioxide per mile driven.
For those needing a refresher in math, 0.24 is less than 0.81. In fact, it is about 70% less. Now, imagine you are charging your EV in Idaho where each kWh of electricity has a carbon intensity of 0.2 pounds. That would be a decrease in carbon intensity of about 94%. As the grid gets cleaner the miles driven by your EV get cleaner as a result. Your regular old car with an internal combustion engine will still emit the same old carbon dioxide year after year. In fact, it will likely emit more as it gets older and less efficient. Just saying.
Furthermore, imagine I am charging my Nissan Leaf with electricity derived from the solar panels on my roof. This represents a decrease in carbon intensity of 100%. Talk about demand destruction. Take that Uncle Carl!