Since the inception of the fuel-efficient stove program in Latin America, TWP has worked with its partners to develop different models of stoves. This allows us to test out new manufacturing methods and new materials; it allows us to continuously refine the efficiency of the stoves; and gives people in our program countries choices in stove costs.

The Justa stove, named in honor of co-developer Doña Justa Nunez, is essentially an insulated masonry box. The key to the higher combustion rates and efficiency achieved by this stove is the "Rocket elbow," created by Aprovecho engineer Larry Winiarski. This L-shaped combustion chamber allows wood to burn up to 70% more efficiently. The body of the stove may be constructed from brick or cinder block, and is insulated with wood ash or other locally available material. The stove is topped with a removable metal cooking surface, or plancha. A built-in chimney vents harmful gases and particulates from the kitchen.

The Eco-stove is a sheet-metal version of the Justa, using the same Rocket elbow technology. These free-standing stoves are manafactured primarily in Nicaragua by TWP partner PROLENA. These metal stoves have gained popularity with commercial tortilla makers, as well as in home kitchens. Eco-stoves are typically insulated with pumice, and also incorporate the built-in chimney. Eco-stove models include the single Eco-stove, double Eco-stove, and the Eco-horno (oven).

The Rocket stove and its variations is the most simple stove design used by TWP in Latin America, and the least expensive. A Rocket stove can be housed in a masonry container or metal drum. It also incorporates the Rocket elbow, but is not vented and is therefor intended for outdoor use. Rocket stove models include the masonry Eco-lenca and the metal Eco-barril.

Please see the slideshow for photos and diagrams describing each of these stoves.