Watt is the unit of Power?
I mean Unit of Power is Watt not Volt.
No where in the world is 750 Volt. You will die out of the Shock.

Anyway Watt is not a concern. You can consume how many watt you want. Air Condition consumes even 2500 Watt of Power at 250 Volt.

Watt is obatined as

Watt= Volt x Ampere
Since Volt remains same at 250 V, Current in Ampere changes.
More Watt means require more Current.