The NY Times provides some great data on the head to head operating costs and environmental impact of driving a Nissan Leaf versus a conventional car.
The one detail that I would like to see the NY Times address is the price volatility of gas prices versus electricity and the role that such volatility plays in determining the actual operating cost of each modal choice. With the rise of the smart grid, electricity prices will vary during the course of the day and smart electric car owners can recharge at night. This means that the 11 cent per kWh charge discussed above is too high. The electric car's operating cost will be even lower than is discussed here.
Now, gasoline prices are volatile over time and the electric car acts as a hedge against rising gasoline prices. It will interest me to see how many 2 car households hold a diversified portfolio with one gasoline car and one electric car and how responsive the utilization of these two cars are as gas prices go up and down. You can't hold gasoline inventories in large quantities in your garage but owning an electric car that you could charge with solar panels or using your neighbor's solar panels would be one way to sharply reduce the gasoline consumption per mile driven. As the chart above highlights, to really get this right -- -we need the electricity to be generated by low carbon renewable sources. In a high carbon area such as Ohio (where coal may generate 100% of power), electric car use may have a greater carbon factor than conventional cars.