In our previous post  in this series, we provided evidence that the existing electrical grid has enough spare capacity to accommodate plenty of plug-in electric vehicles (PEVs), if the right incentives are put in place. In this post, we will discuss a technical problem that has its roots in social behavior.
The transition from traditional powered vehicles to electric vehicles will not be without its hiccups. While the aggregate impact of PEVs on the grid is likely moderate, one concern is clustering, which can be thought of as the realization of the famous comic strip Keeping up with the Joneses . If people buy what their neighbors have, this could lead to a clustering of PEVs in certain neighborhoods which might place excessive demand on local areas of the grid.
Utilities have already started upgrading their infrastructure in order to maintain high standards for service reliability as the future electrical grid grows in complexity. One of the major aspects of this effort is a significant improvement to the electrical grid nationwide as the smart grid  transitions from the drawing board to the field. Since the demand for electricity from an electric vehicle is so significant (about 3-4 kilowatts of power or the equivalent of the demand for electricity of about 1-2 homes), utilities will also need to know where electric vehicles are being charged. The additional power load on electrical grid equipment is significant, and equipment upgrades may be needed in neighborhoods where clustering occurs to prevent blown transformers.
Car manufacturers will appreciate the benefits of clustering because it will increase vehicle sales, but a risk exists due to this phenomenon unless utilities are able to keep up with the potential for concentrated growth in demand throughout the electrical grid.
The next post in this series will discuss frequency regulation and how it could lower the overall cost of owning and operating an electric vehicle while increasing the stability of the grid.
Nick Nigro is a Solutions Fellow