Today, British Transport Minister John Hayes issued a statement that electric vehicles in the UK are taxing the electicty grid but trails of demand responsive smart grid technology should help ease the demand for power. He remarked, "We know the demand for electric vehicles places the national grid under pressure. It’s critically important – we are working on this. It’s particularly important that we charge smart, so we flex demand and take advantage of spare capacity."
In order to estimate demand, you need models for electric vehicle charging behavior which take into account facotrs like range anxeity and trip patterns. Using game theory, it might be possible to predict how different factors might affect behavior. Human behavior is only one side of the equation, energy storage and transmission technology is the other. Work in this area focuses on optimization with smart grids through cooperation. Others are developing genetic algorithms to manage the load.