Will the rise in electric vehicles stress the grid?


As the numbers of electric-powered vehicles grows, questions about whether the electrical grid can handle the power demands are growing. Michael Barnard of Clean Technica looked at the possibility of electric-powered vehicles breaking the grid by the years 2021 and 2040.

If the current global electrical consumption is 0.16% and the expected global electrical consumption is 1.5%, that’s an increase of 1.34% by 2021. Extending out the projections until 2040, Barnard predicts electrical consumption of between 5% and 45% - a wide range but one that takes into consideration the uncertainty as to how many electric vehicles will be in operation.  

The increased interest in electric cars like the models Tesla is selling is proving that there is demand for greener alternatives.

But will that result in a drain on the electrical grid?

“Let’s take California [as an] example and play out an extreme-case scenario,” Barnard writes. “Let’s assume that 10% of all cars on the road are electric, that they are the primary vehicle of 90% of drivers, and they are all 35 kWh/100 km Teslas. There are about 28.7 million cars registered in California. Let’s assume that number goes up to 30 million by 2021 for round numbers’ sake, giving about 3 million electric cars on the road. That gives an annual electrical consumption of about 20 TWh.

“California currently is generating about 200 TWh of electricity annually and consuming about 260 TWh (it’s a net electricity importer),” he adds. “So California would see about an 8% rise in demand from electric cars in the extreme case. There is a lot of excess capacity on every grid and most of the demand will be at night, when there’s even more excess, so there won’t be any issues due to this at all. Electric cars won’t be increasing peak loads by more than a small fraction.”

The Tesla Model X achieves a 92-miles per gallon equivalency, according to Clean Technica. Barnard says that is equal to 35 kilowatt-hour per 62 miles. For commercial trucks, a gallon of diesel is equivalent to 38 kilowatt-hours. The U.S. EPA defines this as miles per gallon equivalency (MPGe). According to Trucking Info, MPGe is “calculated using the equivalent energy in a gallon of gasoline or diesel fuel converted into kilowatt-hours and computing that to an electric motor producing the same amount of energy.”

The Workhorse Group’s electric delivery truck, for example, achieves an MPGe of 30.