What unit is used to measure how fast electrical energy is used?
Power is the rate at which energy is transferred. Power is measured in watts.
A unit is not used to measure power, but energy. A unit is used by British electrical companies to measure energy consumption, and is short for 'Board of Trade Unit'. A unit is equivalent to a kilowatt hour. A watt, on the hand, is used to measure power, not energy -so you cannot relate a unit to a watt.