Cottonwood
Roadster#433, Model S#S37
It is also possible to double your power by using an adapter that combines power from two different 120V legs in your house that are out of phase. See www.quick220.com If you have 15 amp breakers on the circuits, you would set the maximum charging current at 12 amps to avoid overheating your conductors and receptacles. This will give you 12 x 240 = 2880 watts as opposed to the 1440 you would get on 120V.
The problem is that the quick220 will not work on GFI outlets. 120 Volt GFI work by detecting differences between the Line and Neutral currents. The quick220 sends all the current from the Line in one outlet to the Line in the other, out-of-phase outlet. With no current down the neutrals, the GFI's pop immediately.
All new construction has all the outlets in the garage on GFI circuits. To make this work takes some long extension cords into the house in most situations; it's a hassle.