I think it's just a radio transmitter/receiver of some sort. I haven't the slightest idea how much electricity it would use, but I know I was paying $65/month for Comcast internet, and I seriously doubt you're going to be using even 1/3 of that in electricity to power their hub.

BTW, after I signed up, I found out my nephew works for Vivint in a mid to higher level role. I can shoot him an email about your question and get his response.