Xcel Energy currently charges $10.28/month just to hook you up to gas. That means if you do a great job of design and building, and drive your gas usage to zero, you still pay over $120/yr for the privilege of gas heat backup. You can install a huge PV or thermal solar system, but it won't eliminate that charge.
So the easiest way to get rid of it is to eliminate gas to the house.
For all you chefs out there who love to cook with gas, remember that it puts quite a bit of CO into your home. You may want to check out induction cooktops which reduce the chances of anyone burning themselves, and actually heat quicker and more energy efficiently than gas.