We have 49kw load of light fitting in the field what is the appropriate Kva generate to used and please give how to calculate

We have 49kw light fitting loads in the field what is the generator Kva to be used and please give how to calculate

You can see, by the Ohm's Law chart I provided, that the voltage is needed to complete the calculations.

And, if the system voltage is 3 phase, the voltage needs to be multiplied by 1.73, before using Ohm's Law.

Also, since you want to know KVA, need to know the Power factor of the lighting.

So, provide:
System Voltage
Phases
Power Factor