hydro pole vs power pole

hydro pole

noun
  • A utility pole. 

power pole

noun
  • A vertical pole of concrete, wood or steel that carries electric power cables. 

  • A kind of modern anchor on the back of a boat, often one of a pair, that looks like an antenna and goes down on demand to hold the vessel in place. 

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