Do you have natural gas running to your house?
Do you unplug it when you leave? Better safe than sorry.
You're comparing a solar connection, and a natural gas connection, to a gas hose pumping 5 gallons of flammable liquid into an unsealed gas tank, sitting on top of a 30,000 gallon tank of the same flammable liquid, only relying on a small sensor to cut the flow when the tank is full? OK.