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.