Electric cars
Difference Engine: Tailpipe truths
Economist|Apr 20th 2012, 10:20 by N.V. | LOS ANGELES
GETTING the equivalent of 106 mpg (2.2 litres/100km), the Nissan Leaf electric car would
seem a motoring skinflint’s dream come true. Even an advanced plug-in hybrid like the
Chevrolet Volt (Opel/Vauxhall Ampera in Europe), with an energy consumption equivalent to
61mpg, sounds pretty miserly, too. Yet, for all their frugality, neither has been selling
particularly well, despite the present sky-high price of petrol (see “Priced off the road”, July 15th
2011).
With big-ticket items like motor cars, consumers have learned to do their calculations carefully.
As far as electric cars are concerned, motorists have sussed out that they do not make particularly
good financial sense, even with a $7,500 handout from the federal government. They would have
to keep their hybrids or plug-in electrics for seven to ten years to recoup the reward of better fuel
economy. Few keep their cars anything like that long. Even in these depressed times, American
motorists tend to trade in their vehicles after no more than six years.
And when it comes to replacing hybrids like the Toyota Prius, two out of three owners revert
back to petrol power, finds Edmunds.com, America’s most popular site for independent carbuying advice. “Even as gas prices soar, the economics of buying a hybrid vehicle don’t make
much sense in many cases,” notes Lacey Plache, Edmunds.com’s chief economist.
It all comes down to the price of the lithium-ion battery, which nowadays costs a shade under
$600 per kilowatt-hour (kWh) of storage capacity. As an electric car capable of travelling 75
miles or so between charges needs around 24kWh of capacity, the battery alone adds $14,000 to
the price of the vehicle. The result is a car that costs way too much for what it offers in fuel
savings.
A state-of-the-art electric vehicle like Ford’s forthcoming Focus EV, with a claimed range of 100
miles (say, 70 miles in real-world conditions) and an equivalent fuel economy up there with the
Nissan Leaf’s 106mpg, has a base price of $39,200. The petrol-powered version of the same
vehicle, which averages around 40mpg, costs just $16,500. In other words, batteries have to
come down to less than $200 per kWh before electrics can go mainstream. Clearly, those who
buy a plug-in electric like the Ford Focus EV or Nissan Leaf today are making some kind of
statement about their green credentials.
But what kind of statement? While it is impossible to justify buying an electric vehicle, or even a
hybrid, on purely financial grounds, it is fair to say that most people assume that electric vehicles
are far more gentle on the environment than are petrol-powered cars. But is that necessarily the
case?
Electric vehicles may have no tailpipe emissions, but generating the electricity used to charge
their batteries produces plenty of carbon dioxide and other pollutants, including sulphur dioxide,
nitrogen oxides and mercury. Making their batteries, plastics and lightweight aluminium
components produces a whole lot more.
On the other hand, petrol-powered cars may be getting cleaner and greener, but extracting and
refining the crude oil, and distributing the light hydrocarbon fractions to petrol stations, still
produces lots of noxious emissions. And petrol cars, too, are having to adopt ever lighter, and
more energy intensive, materials to meet mandated fuel-economy requirements. The only way to
compare like with like is to adopt a full fuel-cycle (ie, “well-to-wheels”) approach in both
instances.
Lately, the venerable Union of Concerned Scientists (UCS), a non-profit organisation that spun
out of the Massachusetts Institute of Technology in the late 1960s to tackle environmental and
public-safety issues, has had a stab at doing just that. On April 16th, it published a
comprehensive report on the fuel savings and emissions from electric vehicles.
In many parts of the world, electricity is generated mainly from coal—a dirty fuel that casts a
pall over the electric vehicle’s pristine image. The UCS report, “State of Charge”, seeks to
clarify such matters. The UCS finds that electric vehicles charged from the grid produce lower
emissions than a petrol-powered car that gets 27mpg. And they did so, the report claims, even in
places where the electricity is produced primarily from coal.
To get a handle on the problem, the UCS researchers divided America into 13 regions, which
they then classified as good, better and best for charging purposes. Overall, coal accounts for
45% of America’s electricity production, natural gas 24%, nuclear 20%, hydro 6%, renewables
4% and oil just 1%. The emissions produced in replenishing an electric car's batteries depend on
the mix of energy sources used to power a region’s electricity grid. Places that are best for
charging electric vehicles—California and parts of New York—have the lowest proportion of
coal-fired capacity and the highest proportion of hydro and renewable sources in their generating
mix.
The UCS's well-to-wheels analysis shows that a battery-powered vehicle charged with electricity
made from coal produces as much in the way of greenhouse gases as a conventional car that
averages 30mpg. If the electricity is generated solely from natural gas, the emissions are
equivalent to a petrol-powered car averaging 54mpg. And if the batteries are recharged using
solar power, it is like having a car capable of 500mpg.
Here, your correspondent has the first of his quibbles. The petrol car the UCS team uses for
comparison is a notional compact that gets 27mpg. Thus, the team’s claim that even electric
vehicles powered by coal (with an emissions equivalent of 30mpg) are cleaner than comparable
petrol cars.
The petrol benchmark was chosen because in 2010—the most recent year for which data were
available when the study was launched—the Environmental Protection Agency (EPA) fueleconomy figures for all compact cars sold that year averaged 27mpg. Given the huge
improvements in fuel efficiency over the past few years, the average today is more like 35mpg.
“In 2010, only one vehicle—the Smart ForTwo—achieved 40mpg,” notes Edmunds.com.
“Today, the 40mpg club is up to nine vehicles and growing.” That is one of the reasons why
pricey plug-ins such as the Nissan Leaf and Chevrolet Volt have flopped.
With America’s new emissions standards requiring a fleet average of 34.1mpg by 2016,
carmakers there have started peppering their line-ups with frugal imports from their overseas
divisions. Some of the foreign fuel-sippers get even more to the gallon than popular hybrids like
the Toyota Prius which, according to tests by Consumers Union, delivers a real-world 44mpg.
With its advanced three-cylinder engine, Ford’s new Fiesta, which went on sale in Europe last
year, gets 47mpg (see “The balance of power”, March 23rd 2012). The Volkswagen threecylinder up! is capable of 52mpg. Both could soon be heading for American shores.
A second quibble is that no thought seems to have been given to how electric vehicles are
actually recharged. The vast majority are expected to have routine duty cycles, being used to
commute to work and back during the day, and then recharged overnight with off-peak
electricity. What seems to have been ignored in the rush to judgment is the Jekyll and Hyde
nature of the grid as it switches from peak to off-peak power.
Since deregulation, the energy markets in America have become ruthlessly efficient, with the
cheapest power available being shuffled instantaneously around the grid to wherever demand
arises. In the process, electrical power has become a commodity, with capacity traded as local
need for electricity rises and falls. As the sun sets, renewables like solar and wind power become
idle. Meanwhile, generating stations that can be powered down easily, especially those fueled by
natural gas, go offline. As a result, the cheap off-peak juice coming out of a plug in clean-energy
California can hale from dirty coal-fired plants in Wyoming and elsewhere. Much the same
happens in metro areas across the country.
So it is hard to say whether, even in California, an electric vehicle is cleaner than a modern
petrol-powered car. Your correspondent would like to believe it so. But he cannot help thinking
that, despite the abundance of cleaner natural gas, cheap and dirty coal will remain the fuel of
choice for charging electric vehicles overnight for many a year to come. He welcomes electric
cars, whether pure plug-in or hybrid, for the way they can help curtail the country's appetite for
foreign oil. But they are not the saviours of the environment as widely believed. And as many
motorists have already found to their cost, they are nowhere near as cheap to own as their mpg
figures might imply.