Why electric cars are cheaper to drive than gasoline cars

Many look to electric cars not for ecological reasons, but because of greater efficiency, they’re cheaper to drive.

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.

It is cheaper to drive an electric car than the equivalent gasoline vehicle
on fuel costs alone. There are also a big range of maintenance costs
that gasoline vehicle owners pay (like oil changes) that electric
vehicle owners don’t worry about. The amount of savings between
electric and gasoline cars of course depend on the current price of
gasoline. The price of electricity is fairly stable, and is set by
utility commissions, while the price of gasoline jumps around all the
time, and is set by OPEC. Over the long term as the effects of peak oil
become more prominent its expected the price of gasoline will only go
up, leading to even larger savings as that occurs.

Originally published at TorqueNews: http://www.torquenews.com/1075/why-electric-cars-are-cheaper-drive-gasoline-cars

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

About David Herron

David Herron is a writer and software engineer living in Silicon Valley. He primarily writes about electric vehicles, clean energy systems, climate change, peak oil and related issues. When not writing he indulges in software projects and is sometimes employed as a software engineer. David has written for sites like PlugInCars and TorqueNews, and worked for companies like Sun Microsystems and Yahoo.

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