Maybe I just cannot get it. How can anyone call electrical cars green that require batteries needing to be charged by plugging into the electrical grid?

In the United States we get our electrical energy from coal 50%, nuclear 20 %, natural gas 18%, hydroelectrically 8 %, oil and renewable about 4 %. Only 30% of our electrical power comes from non-carbon resources. Therefore, most of the electricity to power the electrical car batteries is going to come carbon sources. http://www.data360.org/graph_group.aspx?Graph_Group_Id=360

And then there is the issue of the material the batteries are constructed from. Lithium one of the major components of the batteries, and the scale at which lithium metal supplies are needed for mass auto battery construction is in question. Also, lithium metal must be commercially formed from other lithium compounds using mass electrical power.

President Obama has stated numerous times that the batteries should be constructed in the United States. The problem is the largest source for lithium comes from dried salt ponds or "salt flats." A briny liquid, underneath the earth’s surface, is pumped out and dried in the sun. The dried material then is processed into lithium carbonate, which requires a huge source of electricity to further process into lithium metal. These salt ponds are located primarily in China and Latin America. The energy needed to create and transport the batteries cannot be determined because the purity of the lithium carbonate varies.

So energy independence will not come from production of electrical cars. And electrical cars are not green.