Unless you buy one of the real expensive refrigerators made to run off the grid you will need more than a small solar panel as most refrigerators use about 1Kw a day and most smaller fridges are energy hogs. I love my propane fridge and it has a built in co2 detector that shuts off the gas when co2 levels reach a certain level. I have used mine for years but it requires maintenance including cleaning the flue and burner screen yearly to maintain complete combustion. I save my solar generated energy for other things.