Every line has a rating, a voltage, a “quantity” of electricity that it can safely conduct from one place to another. Extra High Voltage lines, the ones threaded across open prairies and high mountain passes borne up by huge steel towers, carry from 275 kilovolts (kV) to 765 kV, while those that link the corner pole to the side of your house have a low voltage rating, usually around 50 kV.
