MADISON, Wis. — There is no shortage of electric vehicle skeptics these days.
They view "green" electric cars as a fallacy, and often point out that EVs running on electricity generated by burning fossil fuel are no greener than a carbon-emitting internal combustion engine.
The argument is simple, easy to repeat, and sometimes even rings true.
However, the reality -- as is often the case -- is more nuanced.
Climate Central, an independent Princeton, N.J.-based science and journalism organization, recently issued a report, "A Roadmap to Climate-Friendly Cars: 2013," analyzing the relevance of EVs for climate change. The report concluded that an electric car's climate benefit depends on where its owner drives.
To measure the climate impact of EVs, plug-in hybrids, and high-mileage, gas-powered hybrid cars are, Climate Central's report considers the source of energy for the power grid and carbon emissions -- both from driving and from vehicle manufacturing.
In a state-by-state analysis, the report pointed out:
In states that rely heavily on fossil fuels like coal and natural gas for their electricity, there are many conventional and plug-in hybrid electric vehicles that are better for the climate than all-electric cars.
Indeed, in 18 states, including Colorado, Missouri, New Mexico, Michigan, and Ohio, still heavily depend on coal, or have virtually no renewables and little nuclear power in their electricity mixes. "Driving and recharging an electric car in these states is worse for the climate than burning gasoline in a conventional hybrid or high-mileage car, even when manufacturing emissions are excluded," the report said. In that context, in Colorado, for example, a Toyota Prius hybrid is more environmentally conscientious than a Nissan Leaf or Tesla S, according to Climate Central.
Electric cars are not always the best cars for the climate. See the state-by-state analysis using the interactive map above.
In contrast, in states that have electrical grids with substantial amounts of hydro, nuclear, and wind power that produce essentially no carbon emissions, all electrics and plug-in hybrids work well.
The Climate Central report states:
In 11 states (Washington, Oregon, Connecticut, Idaho, Vermont, New York, New Jersey, New Hampshire, South Carolina, California, and South Dakota), the best electrics are better for the climate than any gasoline car even when manufacturing is included.
Clearly, a greener electric grid is critical for EVs to reap benefits.
Climate Central noted that in many states, a rapid migration to natural gas from coal and the adoption of substantial amounts of wind power are already happening, measurably decarbonizing the grid between 2010 and 2012. These changes have shifted the balance of carbon emissions in favor of recharging electrics vs. burning gasoline in high-mileage hybrids like the Prius, the report said.