No need for Google. Open Sans is.. well, open… You can host the fonts yourself:
http://www.fontsquirrel.com/fonts/open-sans
If you want to be really fancy you can use Bourbon's font-face mixin:
http://bourbon.io/docs/#font-face
There's an excellent case to be made for letting Google (or Typekit, etc.) do the heavy lifting, but I prefer to control my own destiny and tend to favor self-hosting when possible. :)