hydro vs power supply

hydro

noun
  • electrical power supply; specifically, electrical power provided by a utility (as a publicly-owned one); payment or bills for this. 

  • hydroelectric power 

adj
  • hydroelectric 

  • hydroponic 

power supply

noun
  • A source of power such as the mains or a generator. 

  • That part of a piece of electronic apparatus that provides appropriate voltages for the rest of the electronics from the connected AC source. 

  • Used other than figuratively or idiomatically: see power, supply. 

How often have the words hydro and power supply occurred in a corpus of books? (source: Google Ngram Viewer )