What is the comercial unit of enrgy and si unit energy establish the relationship between comercial unit and si unit of energy ?

I am assuming (which is dangerous) that this relates to electrical where the commercial unit of energy is the kilowatt-hour (kWh). The SI unit of energy is the Joule (J).

One kWh is the of 1,000 watts transferring energy for an hour. We can define power as:

Power = energy transferred / time (unit: Watt or J/s)

So

Energy transferred = Power x time

Hence one kWh = 1000 (J/s) x 3600 (s) = 3.6MJ (Mega Joules)