[KarlInOhio]

Like anything based on aluminum, there is a lot of embodied energy in Phinergy's batteries, but they are manufacturing their products in Quebec, where the electricity is almost entirely sourced from hydroelectric stations, keeping the carbon footprint small.

The energy isn't the big CO₂ source in aluminum refining. You heat up the aluminum oxide until it is molten, put in a carbon electrode and run current through it. This results in the chemical reaction 2Al_2­O₃ + 3C -> 4Al + 3CO_2­. Well, what do you know, CO₂ is released. Unless you can capture this or have a carbon neutral way of producing the carbon anode out of atmospheric carbon, this isn't a way of reducing the carbon footprint of driving.

[MrEdd]

But since carbon is a good thing it’s okay.