I have no personal bias in favour of
electric or plug-in hybrids and no personal bias against gasoline cars or
fossil fuels. On the contrary, in an earlier post, I have expressed my
disappointment at not being able to convince myself to buy a hybrid car let
alone an electric car. However, I feel the need to disagree with some points in
an Op-Ed in the WSJ that claims to reveal a dirty little secret about electric
cars and which is based on a paper in an academic, peer-reviewed journal. The
peer-reviewed paper suggests that electric cars are not zero-carbon and the GHG
emissions avoided over the life of the car is heavily dependent on the life of
the electric car. I find nothing wrong with that. But one has to be very
careful in interpreting the results of a life cycle assessment (LCA).
To me
a key sentence in the Hawkins et al. paper is "Our LCA is
attributional and process based." An attributional LCA is a rigorous
accounting of the total material and environmental burden from all activities
connected to the production, use phase and end-of-life of a product or a
service. This is also referrd to as crade-to-grave or wells to wheels analysis.
Researchers and practitioners of LCA generally agree that attributional LCA is
not suitable for making the
extrapolations the op-ed makes based on the paper. One cannot extrapolate two
attributional LCAs to infer what would be the benefits or costs of replacing
one product or technology or another on a large scale. There are several reasons
for this. In this one technology is nascent, i.e., electric car and the other
is mature, i.e., gasoline car. The nascent technology offers enormous scope for
learning-by-doing. At the same time gasoline is getting dirtier because of the
transition to lower-grade resources, like oil sands, heavy oils, gas/coal to
liquids etc. In the high-income countries where expensive electric cars are
first likely to be first adopted, the share of coal is declining in the
electricity mix. The academic paper comes with a warning that it performs an
attributional LCA but the Op-ed which is meant for consumption by the lay
person either does not appreciate this statement or conveniently ignores it.
This can lead one to draw the wrong conclusions.
The op-ed also mentions “Similarly,
if the energy used to recharge the electric car comes mostly from coal-fired
power plants, it will be responsible for the emission of almost 15 ounces of
carbon-dioxide for every one of the 50,000 miles it is driven—three ounces more
than a similar gas-powered car.” I am not an expert on the life of the battery
system of an EV but 50000 miles seems low. I find it hard to believe an
expensive investment will be go under-utilized relative to a cheaper
investment. Obviously, if electric cars are to succeed their battery life has
to improve (the driving range is different issue). I have seen Prius cars that
have logged more than 150000 miles. So the assumption of 50000 miles as the
life and that the electricity is entirely from coal is unreasonable.
Also electric cars impact society in more ways
than one. GHG is one attribute. There are important other benefits and costs.
Life cycle assessment gives no guidance on how one should weight these different
impacts in decision making.
My final complaint is with the statement
in op-ed that “The real challenge is to get green energy that is cheaper
than fossil fuels.” The problem is not that green energy is costly but that fossil
fuels are under priced. So it is unfair and inefficient to force the price of green energy down to that of fossil fuels.
Subsidies to green energy lower the cost of energy consumption and only serve
to increase energy consumption in the long run.
As an environmental economist, I believe
there are cheaper ways to mitigate than switching to electric cars, which may
be more essential in the longer run. So my disappointment with electric cars is
based on cost-effectiveness and the opportunities for cheaper options
such energy efficiency and conservation. By driving less we are causing less
congestion, creating less risk of accidents, incur lower fuel and maintenance costs,
etc., which are not achieved by driving a less polluting vehicle. But alas not
every one is able to drive less and this is where investments in public
transportation and smarter urban planning matter.
