Oh yeah i never explained that bit.

Okay for any power tranmisson application be it your mains voltage or around your car or for me on a ship, the higher the vlotage you use in conducting the power the lower your losses are. Also if you use a higher voltage the conductors can be smaller since they do not have to conduct such a high amperage to move a set amount of energy

For example your nearest power station will be poducing power at about 22Kv or higher and then that goes through the overhead wires then it comes to sub stations where it gets dropped with a transformer to a lower voltge like 6.6Kv and then it travels a wee bit further and gets dropped again down to 440V (three phase) and then once it gets to the final substation they then drop it to 220 for us or 110 for you lot.

If you started at 220V at the generators the losses by the time it got to your house would be huge.

These losses come from resistance in the cables and since power is basically volts mutiplyed by amps this means to move a load of energy you need high amps or high voltage.
Now high amps heats the conductor instead of heating your house so there fore to counter this we need to drop the amps or drop the resistance. Dropping resistance implies we go for superconductors (ultra expensive) or bigger cables which ends up being to damn heavy and impracticle to run. So it is easier to drop the amps by uping the voltage.

now i could explain the advantages of three phase but it is beyond me but i know three phase is better and your car already has a three phase generator fitted just it rectifys it out as DC