hydro vs wattage

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 

wattage

noun
  • An amount or power (especially electric), expressed in watts, kilowatts etc. 

  • The power requirement of some electric appliance. 

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