what is a watt a second
A watt second (also watt-second, symbol W s or WÂ·s) is a derived unit of energy equivalent to the joule.[1] The watt-second is the energy equivalent to the power of one watt sustained for one second. While the watt-second is equivalent to the joule in both units and meaning, there are some contexts in which the term watt-second is used instead of joule. The kilowatt hour (kWh) is equivalent to 3,600,000 watt-seconds and is a unit used in the electricity market, and by producers of electricity.