I hate paying for online photo storage… Google, Apple, whomever. So I normally let my phone backup the photos and then suck them down to a hard drive to save space. And, while I normally use Dropbox for this, I recently found about 6GB of photos in Google that I had forgotten about. Now, it is possible to setup Google Drive and Google Photo Backup to automatically sync with your Mac or PC, but there actually is an easier way: Google Takeout
With Google Takeout you are able to select which items you want and pull down an archive of those items. The best part is that there are no downloads or installs required.
Here’s a link to the Google Takeout Settings page to help get you started:
https://takeout.google.com/settings/takeout
I hope this helps. =)