You can save a lot of your fuel needs on those less than sunny days by using a rocket stove. (see previous posts) But you can save even more fuel by using a thermal cooker (pictured at bottom) or a wonder box. (pictured at top and middle) These are heat retention cookers. After you bring your food to a boil, remove the pot from the heat source and place it inside your thermal cooker or wonder box. It will continue to cook for 6 to 8 hours without any additional fuel. You can purchase a thermal cooker but you can make your own wonder box. It's a styrofoam filled bag with a lid which is also filled with styrofoam. (Using different sized pellets makes for the best insulation.) The size of the bag will depend on what size pot you're going to use. Check online for the many different methods of making a wonder box.