Stacked pots really changes the game in solar cooking. A 3 stacked pot will allow you to cook meats in the bottom, potatoes in the middle and rice on top. The meat and potatoes will slow cook and the rice will cook faster. Once the rice is done you take off the pot and check the other two items. I have found in numerous tests that the middle pot heats up the slowest. The top and bottom heat up at about same rate. But after about 1 hour they are all similar temperatures. So you cook the easy fast stuff on top and the slower longer items on the bottom. Cooking with 3 pots and more food in them takes longer. That is logical, but cooking with 3 pots allows you cook various dishes, that take different times. It is faster and easier to cook three pots in one solar cooker than it is with 3 solar cookers.