Why electric cars are cheaper to drive than gasoline cars
Among the benefits of electric cars is cheaper fuel costs, that is the cost per mile for fuel to run the vehicle. A couple weeks ago Consumer Reports released a report comparing gasoline and electric cars, showing electric car fuel cost was a fraction of gasoline car fuel cost. A recently released video from an electric car fan, Peder Norby (below), claimed his electric car (a leased Mini-E) costs 30 cents per gallon equivalent in fuel costs, giving us an excuse to go over the figures.
Consider that companies around the country with delivery truck fleets are buying electric trucks. This isn't even primarily for for ecological reasons, but because electric trucks cost less to operate than do equivalent diesel trucks. Fleet owners know to the penny what it costs to operate their truck fleet, and know that switching to fuel efficient or electric trucks saves money helping their business bottom line. The key is lower fuel and maintenance costs, adding up to a lower cost of ownership, so long as the electric trucks' range fits delivery route distances.
Retail vehicle owners don't have quite the same need to minimize costs. Lord knows there are many factors going into why someone buys one car or another, but we, the retail car consumers, could still benefit from the savings.
To make one thing very clear, this comparison is looking solely at the operational cost to drive an electric vehicle, and not at the total cost of ownership.
Let's compare two hypothetical cars, one is electric having a 24 kilowatt-hour battery pack and a 90 mile range (essentially the Nissan Leaf), the other is a similar sized gasoline sedan getting a typical 30 miles/gallon. Traveling 90 miles in the gas car requires 3 gallons of gasoline, costing $10.50 if gasoline is $3.50 per gallon, while the electric car would require 20 kilowatt-hours (or more) costing $2.20 for the electricity if electricity is 11 cents a kilowatt-hour. Same distance traveled, quite a bit less cost. A 90 mile daily trip is more than the typical daily commute because most people drive less than 40 miles/day commuting.
That's all well and good, but how do we convert this to a cost per gallon equivalent? On the gasoline car we know the cost per gallon, it's whatever we're paying at the pump this week. Electric cars get their fuel by the kilowatt-hour which is not directly comparable to cost per gallon. The standard conversion is the Gallons Gasoline Equivalent chart published by the EPA which says it takes 33.41 kilowatt-hours of electricity to equal the energy content of a gallon of gasoline. Which means our 24 kwh electric car has the equivalent of 0.72 gallons of gasoline on-board, which begs the question of how it can go 90 miles on that small a quantity of energy. The answer is that electric drive trains are hugely more efficient than gasoline. As Peder Norby points out in his video, the noise and heat given off by gasoline engines are symptoms of inefficiency, while the quiet smooth ride of an electric car is a symptom of their efficiency.
In the gasoline car we're comparing with 90 miles requires 3 gallons, 30 miles requires 1 gallon, while in the electric car the 20 or so kilowatt hours consumed gives 90 miles, meaning it takes 6.7 or so kilowatt hours to equal the range of one gallon of gasoline (in our comparison car). This adds up to 75 cents (or so) per 30 miles, which roughly speaking means a 75 cent cost per gallon equivalent. For whatever its worth, the figures Consumer Reports published said the Leaf costs $1.05 per 30 miles. That is, defining "gallon equivalent" as the energy required to travel the distance in which an equivalent gasoline powered car consumes a gallon of gasoline, rather than the EPA Gallons Gasoline Equivalent meaning of "gallon equivalent".
Despite having climbed out on a shaky limb, the $0.75 or $1.05 per gallon equivalent is pretty good. It's a lot less than the cost of gasoline these days, but Norby claims his cost is 30 cents per gallon. How could he be making this claim?
It would have to be the solar panels on the roof of his house. His cost for electricity is not the retail price charged by his utility, but is instead an amortization of the cost of the solar panels. It's well known installing solar panels creates electricity cost savings that pay for the solar panels over a few years. A person owning both solar panels and an electric car would have an even faster payback period for solar panels, because they're offsetting the cost of fuel to power their car.