Originally posted by @ponderable
1. "Work is heat and heat is work" (or energgy is convertible)
2. heat can not [b]of itself pass from a Body to a hotter Body.
So in essence if you invest some work you can Transport heat from a cold Body to a hot Body. The Refrigerator does that. (kompressing a fluid cooling the compressed fluid, then expanding that fluid, which will ...[text shortened]... vely cold ground to the relatively hot flat. And you Need electricity for it to put the work in.[/b]
And you can do that job with no moving parts in a Peltier device, a semiconductor that does that job with just electric current input. Not exactly the most energy efficient device but it works for beer at the beach, they are built into beach coolers now, some with solar panels on the lid.
Usually they plug into a car cigarette lighter socket, 12 volts at around 10 amps, 120 ish watts which you won't get from a solar powered lid but it can recharge some kind of battery if left out all day in the sun. You get about 125 watts per square foot of solar energy hitting the top of the atmosphere and you get say half that on the ground so say 60 watts per square feet, you need about 10 square feet to get full power for the refrigerator from solar alone. 2 square feet but since it is only 20% efficient, 5 times. 2 = ten square feet.