For the project this time I researched the propane system and also prices for the propane tank. Matt helped me understand how the propane system works. It is an easy way to be off grid and is cheap compared to how much energy would be wasted if we used a DC or AC refrigerator, since we are getting rid of the oven that is a less thing to worry about. Besides that we plan on reusing the gas cook top, instead of throwing it away. We will be using a 20lb propane tank that will be placed on the tongue.
Then the tank will be connected with the appliances with rubber lines with 3/8” brass fittings that will be covered with Teflon tape around the threads that is not expensive at all. The gas will go to the T and then be sent to the appliances like the refrigerator or the stove top.