Weekend Project: How to Build Your Own Cheap, Simple Solar Oven

Simple Box Cooker

Renter friendly.

Project Time: Afternoon.

Cost: Inexpensive ($5–20).

Energy Saved: Low. Cooking’s relatively low energy requirements (4 percent of average energy budget) and solar cooking’s intermittent availability make dependence on at least one other cooking system all but certain.

Ease of Use: Moderate. Cooking can be done only on relatively sunny days and works better in summer than in winter.

Maintenance Level: Medium. How long this solar oven lasts depends on how well you take care of it. If it gets wet repeatedly, it will eventually turn to mush, so bring it inside when it’s not in use.

Skill Levels: Carpentry: Basic.

Materials: Two large, shallow cardboard boxes—the inner box should be at least 18 x 22 inches, preferably just a little bit taller than your pots; the outer box should be a little larger in all dimensions so there is at least 1–2 inches of space between the two boxes when they are nested. You’ll also need corrugated cardboard at least 6 inches longer and wider than the outer box to make the lid; window glass (or Plexiglas) at least 20 x 24 inches and longer and wider than the inner box by 2 to 3 inches; a thin, black metal sheet, sized equal to or slightly smaller than the inner box; 50 feet of aluminum foil; dry plant fibers such as leaves or straw or at least 50 sheets of newspaper, quartered and crumbled; glue silicone caulk; and rigid wire (hanger wire, for instance).


Tools: Paintbrush, utility or other knife, pencil, straightedge.

Caution: Solar cookers, especially parabolic varieties like the CooKit (described next), have the potential to cause retinal damage from the concentrated solar rays. Be careful to avoid looking at the bright reflections from any of these solar cookers.


Construction Steps

Cut the window opening in the outer box. See figure 4.3. Turn the outer box upside down. On its bottom, center the inner box and draw a line around it. Cut out this piece to make a window opening the same size as the inner box. There should be a small rim on all four sides, 2–3 inches wide. On the lid piece— the extra piece of cardboard—center the outer box and trace around it (these are the fold lines). Extend these lines out to the edges of the lid piece. Center the inner box between the fold lines on the lid (that you just drew) and trace around this box as well. Cut only three sides of the inner line, two short sides and one long one. Fold up the resulting flap for the reflector, creating a window frame opening the same size as the inner box.

now click to finish oven....:)