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Electric Cars Can Have Worse “MPG” Than a Civic

North Carolina is on track to increase the number of electric vehicles on its roads. As a matter of fact, one of the key facets of Gov. Roy Cooper’s Clean Energy Plan is the electrification of transportation in the state. Specifically, he wants to increase the number of so-called “zero-emission vehicles” to 80,000 registered by 2025. This week, Senior Fellow at the John Locke Foundation and former secretary of the N.C. Department of Environmental Quality, Don van der Vaart, published a research brief on electric cars in North Carolina. Dr. van der Vaart explains:

Governor Cooper’s Executive Order 80 claims to seek reductions in greenhouse gas (GHG) emissions to combat global warming. A major component of the order is the promotion of electric vehicles in North Carolina. Ironically, promoting electric vehicles will increase electricity use and actually exacerbate global warming to the extent GHGs are the cause. Instead, Governor Cooper should focus on reducing the carbon intensity of our electricity grid by pushing for nuclear power.

Dr. van der Vaart says the idea that electric vehicles are more efficient than cars with fuel-powered internal combustion engines is a common misconception. To illustrate, van der Vaart uses a 2019 Honda Clarity electric vehicle:

The EPA (battery to wheel) fuel efficiency is given as 114 MPGe… Unfortunately, MPGe only describes the efficiency of the electric vehicles in converting the energy stored in the battery to mechanical energy, i.e., turning the wheels. Values of well over 100 MPGe are reported making electric vehicles appear to be very fuel-efficient because it ignores the energy required to charge the battery.  It should not be used to compare electric vehicles with internal combustion engine vehicles…

[If you] take into account the losses associated with electricity generation, transmission, charging, etc., the efficiency is calculated to be 34.5 miles per gallon. This represents the car’s efficiency assuming the electricity was generated by gasoline. This can be better compared with the fuel efficiency for the gasoline version of the Honda Civic of approximately 36 miles per gallon, although losses associated with the transportation of the vehicles to retail outlets would reduce this number (Emphasis added).

Dr. van der Vaart notes that the efficiency of an electric car depends on the source of its electricity:

The Honda Clarity discussed above had a calculated fuel efficiency of roughly 34.5 miles per gallon, assuming gasoline as the fuel. Using the carbon dioxide (CO2) emissions associated with the combustion of different fuels as a basis, if coal were used as the exclusive fuel to generate the needed electricity, the fuel efficiency would drop to 25.8 miles per gallon. This represents the effective fuel economy that would emit the same amount of CO2. Similarly, assuming natural gas as the basis, the effective fuel economy would rise to 46.4 miles per gallon. The reality in most markets in the United States lies somewhere in between.

Dr. van der Vaart says that the current makeup of our power grid would not reduce greenhouse gases (GHGs), let alone emit “zero-emissions.” He states:

[T]he current grid is not becoming less carbon-intensive. Instances of GHG reversal have been reported in other markets, most notably Germany. Under such a trend, the addition of electric vehicles to the nation’s fleet would increase electricity usage and be counterproductive.

North Carolina should not promote the electrification of our transportation system until after the carbon intensity of our grid has been reduced.

Read the full brief here. Watch Dr. van der Vaart’s full speech at the John Locke Foundation on the topic here.


Brenee Goforth / Marketing and Communications Associate

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