is it possible to use the google.maps api library on the node.js server side?

You could use a module like node-googlemaps https://github.com/moshen/node-googlemaps that has already wrapped the API for you. Or, you could use any node module that will help you make API requests:

Mikeal's Request: https://github.com/mikeal/request

Restler: https://github.com/danwrong/restler

Although, I'm not sure about the utility methods specifically.