A permanently installed Generac home backup generator protects your home automatically. It runs on natural gas or liquid propane (LP) fuel, and sits outside just like a central air conditioning unit. A home backup generator delivers power directly to your home’s electrical system, backing up your entire home or just the most essential items. Now coming with FREE Mobile Link™, allowing you to monitor the status of your generator on a phone, tablet or computer from anywhere in the world. How It Works.