Honorable Mention

H2Oven is an appropriate technology approach that results in a solar oven / desalination. By using economic materials such as clay, PET and aluminum, H2Oven cooks and obtains safe water freely, employing only clean energy.

Through a water lens, contained in a concave PET receptacle, food is slowly cooked (it can produce heat for maybe three hours on a clear day). The clay works as a thermal insulator, keeping the heat inside. The aluminium, conversely, works as a conductor on the inside. The sun rays (heat energy) pass through the water lens and raise the temperature using the principle of refraction (like when something is burnt using a lens). This lens can produce temperatures of 175°C (350°F) to 345°C (650°F).

Since water scarcity is also an issue, the container (the concave PET receptacle) can be filled with seawater, creating the lens that will allow us to cook. By taking advantage of the heat in the oven, if the oven is filled with seawater instead of food it is also possible to desalinate. Seawater evaporates while ascending, then, when condensed, is deposited in the inner cavity (similar to a rain gutter), leaving the salt and other impurities at the bottom.

Only with an object which can be carried easily, that does not need maintenance and only requires sun and water in the lens, it is possible to cook plus obtain distilled water. Other cooking or water obtaining methods are expensive or demand electricity, which add more problems than solutions.

This product has a simple production: the ceramic oven can be build using a pre-designed mold, then, it only requires an aluminum coating inside. For the lens, it is needed a wooden mold with the correct curvature (predesigned with computer and cut with a milling machine). This process only has to be done once, since when you have the mold you can start to produce in series. Then, with this mold, the PET plate is thermoformed and results in the receptacle.

People who have bad access to energy or clean water that live in sunny areas would be benefitted from H2Oven. The scarcity of safe water and electric energy is the issue intended to solve.

Where did this idea come from? The first question was how we can cook using the sun. Through the idea of a water lens, the prototype of the oven was designed. Research about refraction and desalination was made, then the materials were selected considering recyclability and economy. Finally, the oven was redesigned, adapting the form to consider ergonomics, stability, transportability and recapturing water.  

Cooking and obtaining safe water only using solar energy along with recycled materials is now possible and affordable for everyone. Plus, its simple production and economic adds value to this proposal.