If a generator is generating 20MW and only 5MW is used where does the other 15MW goes?
1- Goes to auxiliary of all electrical equipments that ensure the properly working electrical system.
2- Goes to loss( permanent and variable loss) in all electrical equipments such as transformers, conductors, mortors, compensators that we cannot disconnect from the voltage of line.
But if your question is real, I thing your generator surly will tripped due to over frequency relay is working. If is not real, I thing is the …… question.