Checking a Skeptic’s Fuzzy MathThursday, March 14, 2013
Bjorn Lomborg’s recent opinion piece in the Wall Street Journal, “Green Cars Have a Dirty Little Secret,” argues that the environmental benefits of grid-connected vehicles do not justify federal investment. The author is mistaken on both the benefits to the environment and the benefits to the taxpayer.
A substantial body of scholarship has already demonstrated the greenhouse gas benefits of grid connected vehicles. Studies such as those by EPRI/NRDC and Union of Concerned Scientists (UCS) have found that, even with a coal-dominated grid, the greenhouse gas benefits of grid-connected vehicle exceed those of conventional vehicles. The UCS studied the total emissions reductions of electric drive in every region of the country. They concluded that no matter where in the U.S. an EV is charged and operated, electric drive vehicles have fewer total well-to-wheel emissions than the average gasoline-powered vehicle sold today. Even when charging an EV in regions with the dirtiest grid, it would still produce fewer emissions than the average new compact gasoline-powered vehicle.
These benefits expand as the grid becomes cleaner and more efficient, and it is doing so faster than anticipated. Natural gas net generation rose by 21 percent from 2011 to 2012; more than half the states in the U.S. have a renewable standards portfolio and greater efficiency and intelligence are being added to the production and transmission of electricity.
Lomborg’s assertion is also based on the relative energy intensiveness of electric vehicle production, as modeled by a single Journal of Industrial Ecology (JIE) study of projected production and use of pure electric vehicles in Europe. The authors of this study explicitly acknowledge the limitations and uncertainties of their model and findings. The JIE study cautions – and demonstrates – that changing any assumptions “regarding battery mass, vehicle lifetime, vehicle efficiency and electricity mix can all potentially alter our base ranking for global warming potential.”
Simply stated, their assumptions in all of these areas are in need of changing. The numbers need to first match the reality of electric drive vehicle production. Critically, the study’s foundational assumption of the manufacturing intensity of electric vehicle production (87 to 95 carbon dioxide equivalent per kilometer) are up to three times higher than recognized estimates.
Second, the study is modeled solely on pure battery electric vehicles, a single battery and limited battery chemistries – throwing another wrench into Lomborg’s math. This is certainly not an accurate picture of today’s production of plug-in vehicles – never mind what production may look like in 5 years. Vehicle models, component materials, chemistries and sizes are already substantially more diverse than assumed here. Further, the JIE study does not capture the efficiencies of a maturing supply and manufacturing chain, which itself is being fueled by an increasingly cleaner grid.
To reach his tortured conclusion, Lomborg
has to compound the study’s shortcomings by
averaging the flawed production emissions
impacts over a cherry-picked and
unrealistically short vehicle lifespan of
50,000 miles. The warranty on a Nissan
Leaf is for 100,000. The authors of the
study acknowledge as much, noting that electric
vehicle lifetimes could reach up to 300,000 km
– or 186,000 miles. Those are
conservative estimates when looking at how long
vehicles are actually remaining on the road.
Lomborg’s conclusions are not born out when held against real life numbers. The only thing the opinion writer and report gets right is the importance of a comprehensive accounting for energy costs and benefits in our national policies. To that end, we would urge policymakers to consider the billion dollars a day we spend on imported oil, the economic and environmental consequences of dependence on a single global energy commodity, and the “all-costs” policies employed to secure it when evaluating investments in the electric drive alternative. That’s the math taxpayers need to see.
The Electric Drive Transportation Association (EDTA) is the trade association promoting battery, hybrid, plug-in hybrid and fuel cell electric drive technologies and infrastructure. EDTA conducts public policy advocacy, education, industry networking, and conferences. EDTA’s membership includes vehicle and equipment manufacturers, energy companies, technology developers, component suppliers, government agencies and others. For more information about EDTA and its members, visit ElectricDrive.org.
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