None. Power measured in watts is calculated by a number of equations, one which is probably useful to you is P=V x I (Voltage x Current) So you could say 1W = 1V x 1A.
http://wiki.answers.com/Q/How_many_watts_equal_1_v...

Depends on the Current. P=IV. All you have is Voltage (V) you need the Current (I) to get to your answer.
http://answers.yahoo.com/question/index?qid=201009...

Watts = Volts * Amps, so 1Amp*120 Volts = 120 Watts.
http://www.chacha.com/question/howmanywattsequa...

There are no watts in a volt. Watt is a measure of the rate of energy transfer, while voltage is the 'pressure' of the electricity.
http://www.kgbanswers.com/howmanywattsequalav...
