Those of you that are on solar or wind power and using DC lighting and/or appliances, what is your experience with it regarding wiring and costs? I know of propane or other appliances, but if you have a DC refrigerator or freezer, how does that compare to having an AC? How about DC 12 volt lighting like the lights in an RV camper? Does anyone use these as permanent instillations in their off grid house? Wiring? DC wiring? Is this required? What about plug in receptacles for AC use?