This could come in very VERY handy in a grid-down situation, and is also fully portable and easy to set up and take down. All you need is 16 firebricks (NOTE: Be sure to use fireproofed brick or quarry-type rock for safety purposes. Non-firebrick or non-quarry type wild rocks can potentially explode if heated, due to moisture retention and small air bubbles inside], and of course, some small kindling/ drywood. Rocket stoves when correctly assembled and used, burn so hot and heat stuff up so fast, that there is very little smoke produced in the process. Here is the link:
[Of course, you don't necessarily need to make your own brick like they do in the video. You can just buy 16 firebricks from any hardware supply store, and assemble your own rocket stove according to the technique shown in the video].