This is a hodge podge of topics, but one of the key aspects of this is the solar powered. I would like to be a very well insulated room on a 8'x14-16' flatbed trailer to serve as an above ground root cellar. Walls and floor will be r-30, ceiling r-50. It will very likely be pretty noise proof also. At first I was thinking of putting a chest freezer or two inside with a new thermostat set to 50 degrees. Option 2 is to not use chest freezers inside - unless it is actually to freeze something but to keep the entire room chilled to 50 degrees. Chilling would be done with 2 window a/c. One is probably enough for this size room, but the second one would serve as a backup. I have seen "thermostats" that make an a/c function as a freezer in a walk in unit. Basic, absolutely must requirement: to be able to power this thing from the sun. Do you think 72 sq. ft of solar panels can make this work? I would put batteries in for 2 days of operation, but really, when the sun doesn't shine, it is usually not so hot, so the a/c would not be in use. Any suggestions? A stupid idea? I will not be in a position to consider underground or in ground storage for the next 3 years, but I want to reach my food lts goals in about 3 years.