Tailpipe to Smokestack?

A recent article in Sustainable Industries’ TrendWatch 2011 magazine highlights the rapidly growing electric car economy. Author Sara Stroud cites Pike Research data, which suggest that over 3 million electric cars will be sold in the US and an estimated 4.7 million charging stations will be installed worldwide by 2015.

The massive scale-up of infrastructure and capital required if the US realizes these predictions present tremendous opportunities and challenges for communities across the country.

As a member of the New Energy Cities team I have spent time thinking about the role electric cars will play in our communities in coming years.  So, when a friend recently asked about the impacts of electric cars on greenhouse gas (GHG) emissions I thought I had a good grasp on the issues.

He was pessimistic about the overall impact on emissions, which forced me rethink some assumptions.  He argued that electric cars will simply redirect emissions from the tail pipe to the smoke stack.  His conclusion encouraged me to put together some simple back-of-the-envelope calculations that will help contextualize the impacts of electric cars on cities’ GHG emissions profiles.

For the sake of comparison, I pitted New Energy Pioneer Community Edmonds, WA against Nashville, TN.  Both communities are first launch cities for the Nissan Leaf.  Edmonds is also part of the EV Project, which represents the largest deployment of charging stations to date.

Edmonds receives power from an electric grid with very low carbon intensity (close to 1/10th the national average), while Nashville is slightly worse than the national average link.

Due to this fact, for Edmonds electric cars represent a massive reduction in transportation GHGs relative to gasoline vehicles.  Even compared to a gasoline vehicle that achieves 50 mpg, such as the Toyota Prius, electric cars like the Nissan Leaf will reduce emissions by up to 10 times, assuming the Leaf achieves its advertised 100 mile range per charge.

Edmonds EV Chart resized

On the other side of the country, the story is much different.  While there are GHG emission savings to be had, the overall impact in cities like Nashville is likely to be much less significant, in the order of 1 or 2 times less.

Nashville Chartx

Each community will need to consider electric cars within their individual contexts and for some, incentivizing electric car use may not be the best use of public funds, at least in the early stage adoption of electric vehicle technology.

, Climate Solutions