I remember standing engine room watches when our submarine was transmitting HF. You could watch reactor power fluctuate significantly with the transmitter activation.
Fortunately, my power company's coal-fired plants are safe. I'm not one of the contester "big guns" in this hobby. I long ago found out I could work anywhere in the world on 100 watts or less.
It's funny: you can have a radio conversation between someone with $100,000 of radios/antennas and someone who can put their whole home-brewed station in a pocket, and they're both happy as clams when done.