The Green Pail retained heat cooker holds many foods at cooking temps long enough that simmering is not necessary. It will hold 7 liters of pintos hot long enough to cook them well done and keep them above 170 deg F for 5 hours.
The Green pail is basically an inner shell isolated from an outer shell with loose fill insulation.
The Green Pail retained heat cooker could be useful because:
1- It is made from recycled plastic pails
2- It saves the energy that it takes to simmer food.
3- It keeps the heat out of the kitchen saving summer time ac cost
4- It can be made locally from local materials with local labor.
5- It saves the time necessary to watch food simmer, you can simply set it and forget it, walk away and leave it for hours.
6- It can hold food at safe temps between meals making refrigeration unnecessary, which could be handy in off grid situations.
7- It is a street vender, micro enterprise design that someone could build and sell at flea markets, garage sales.
Please view the detailed instructions how to build at Instructables