I don't think you can do that. The element will still use 3000w, which will result in overload of the circuit and trip the breakers, blow the fuse, or melt the wires and cause a fire.
Edit: 3000w on 240v is 12.5A. May not be enough to trip the breakers, but is still above the current rating of the wiring and sockets etc.
Edit: 3000w on 240v is 12.5A. May not be enough to trip the breakers, but is still above the current rating of the wiring and sockets etc.