Are electric cars truly carbon emission-free, if the source of the electricity is a carbon source?

There is common perception that electric vehicles are completely free of carbon emissions. That prompted Lois Kelln from Red Deer, Alta., to ask if that was true, give that the source of electricity is usually a source of carbon as well.

Dr. Melike Erol-Kantarci, an assistant professor in the School of Electrical Engineering and Computer Science at the University of Ottawa, says that is absolutely true. But the amount of carbon dioxide electric vehicles are responsible for will vary depending on where you live. 

In Ontario for example, most electricity is nuclear or hydro, which are a very low source of greenhouses gases. But in places like Texas where coal is still prevalent, the electricity generated to power electric vehicles will emit much higher amounts of carbon dioxide. 

There are other factors to consider when evaluating the relationship between electric vehicles and carbon emissions. The plants in which the vehicles are built emit carbon. Charging stations for electric vehicles often draw power from the electrical grid as well, making for another source of carbon emissions.