Central Vacuum Automatic Dust Pan

Hello, I'm wondering how this product would help save energy while I clean? Since this site is about building green I'd assume it would me electrical energy am I right? If anything you are using more energy by using electrical energy to pick up the dirt instead of bending over with a dust pan. Or is there something else I am missing? Anyone Know? I purchased one to be installed in our new home that is being built I'm just doing some reasearch.

Thanks,
Mike