So, how much power does it take to drive an efficient supercharger like a screw type? The most efficient type of supercharger, flowing 265 cfm and developing a boost of 11.5 psi, takes 14.5kW to drive it. Figures aren't readily available for centrifugal blowers, but they'd be of a similar magnitude. So the best blower design (the same type that's used on the Mazda 800) takes about 14,500 watts to drive it on a modest-sized engine. This power is derived from the engine via a belt connecting the blower to the engine's crankshaft.

But let's say that instead of using a belt-drive from the engine, we power the supercharger by using a 12 volt electric motor powered from the car battery. For an electric motor power of 14,500 watts, we'd need a current flow of about 1000 amps (14,500 watts divided by 13.8 volts = 1050 amps). So, to supply the current to drive an electric supercharger having the same airflow output as the most energy-efficient type currently available, it would take 1000 amps. To generate this much electrical power would require at least 8 heavy-duty alternators bolted to the engine. Furthermore, to handle this current, the wires connecting the battery to the supercharger would have to be enormously thick - perhaps brass or copper bars 10mm square would be needed.