Geothermal back-up question
I'm buying a house that has a 3 coil geothermal system with a heat pump. I don't even know what that means, I'm currently researching it to get a little more knowledgeable about the system in general, so please bear with me.
My question is about back-up heating that I've read about in several posts. Does this mean an entirely separate system, or merely a backup energy source? I'm having a 20kw diesel generator installed, does that satisfy the backup needs of a geothermal system? I live in a cold climate, I want to make sure I'm covered.