When is maximum power transfer to a load important in AC circuits?

[NewtonianAlch]

So I have a question that I have to answer that goes like:

1) Give some examples of practical situations where it is desirable to maximize the
power delivered to the load.

This is in reference to A.C Power analysis and understanding maximum power output is achieved when the the Thevenin impedance is equal to the load impedance.

I guess one reason I have trouble answering it is because I might not be understanding it correctly; isn't it generally desirable to maximise power to a load so that it runs smoothly? For e.g. if you're using a dryer, you want to have your clothes dried quickly, not having it running forever because the power to the load isn't enough. An A.C that's not cooling the environment properly because the power isn't enough.

I guess one other reason could be that low power at the load with a constant voltage means more power is dissipated elsewhere in the circuit -> overheating, energy loss, inefficiency.

 

[rude man]

You have a source of emf like a generator. Say its internal impedance is Z_m. You want to extract the maximum possible power to a load. What should the impedance of that load be?