Internal combustion engines (gasoline, diesel, natural gas) are only approx. 20 percent efficient. Electric vehicles are closer to 100 percent efficient, at least in terms of converting stored electricity into mechanical rotation of the wheels.

That means electric vehicles will use 1/5th of the total energy that an internal combustion engine uses, even without regenerative braking. The remaining energy that it does use can be generated centrally from a wide variety of fuels: biomass, solar, wind, nuclear, hydro, natural gas, diesel, geothermal, etc. These energy sources do not have to be portable, and central generating stations use high efficiency turbines, upwards of 60 percent or triple the carnot efficiency of automobile engines. Total system energy consumption is thereby reduced by a factor of 15.

But your estimate should be reduced by a factor of 5 at the refuelling station level, or thereabouts.