A solar cooker is one of the cheapest and easiest ways to make use of solar energy, whether it's your first foray into solar power or you've got solar panels covering your rooftop. And while there are no shortage of designs available in print and online for making your own solar cooker, every last one utilizes the same simple principles.
The bare-bones solar cooker described in this article utilizes the most basic of materials. Truly, you could build a fully functional solar cooker all your own for less than .
The materials you'll need to gather for building your very own solar cooker are:
o 2 rectangular cardboard boxes;
o 4 pieces of flat cardboard;
o extra boxes and cardboard (to be cut up into pieces);
o 1 small roll of aluminum foil (18" wide);
o 1 piece double-strength glass (1/2" longer and wider than the smaller of the 2 cardboard boxes);
o black paint;
o white paper glue.
A solar cooker is comprised of 2 main elements:
o an oven;
o and a solar collector
The Oven
The 2 boxes comprise the oven to your solar cooker. One of them must be able to fit inside the other with about 2-3" extra space all around. A good sized outer box for a medium sized solar cooker is around 120-160 square inches. The smaller box is where you'll place the food that your solar cooker is to cook.
The 4 pieces of flat cardboard comprise the solar collector. They should be around 2' x 3' in size. Avoid double-strength cardboard as it is unsuitable for this task.
Now carefully cut up some of your extra cardboard so that you can lay them flat in the larger of your 2 boxes. Lay enough of these down so that when you place the smaller box inside the larger one, its top rim sits an inch below that of the outer box.
Next tuck in your larger box's opposite flaps and then place the smaller box inside. Cut up more spare pieces of cardboard and stuff them into the space between the two boxes, wedging the smaller one in good.
Place the pieces in such a way that, when the glass piece is laid on top of the smaller box, it creates a seal so heat won't escape. You should, however, be able to wedge a finger underneath the glass when it is in place in your solar cooker so that you can lift it up when you need to.
Next, paint the inside of your solar cooker black.
The Collector
The use of solar energy requires a collector to "catch" it, and now you're ready to make yours. Take your flat cardboard pieces and cut them into trapezoidal shapes. A trapezoid is two parallel lines of unequal length (one shorter, one longer) connected by two diagonal lines running at equal, but opposite, angles (think of an anvil, like the one Buggs Bunny drops on his unsuspecting marks).
In this case, the shorter side should be the same as the length and width of your outer box, and the wider interior angle (where the diagonal lines connect with the shorter parralel line) should be 60°.
Glue the flaps of your larger box down against the outside of the box. Glue the aluminum foil to one side of your anvil-shaped solar collectors.
Then glue the collector pieces of your solar cooker, foil side facing in. The shorter edges get affixed to the rim of the outer box. The angled edges of the collector pieces get glued to one another. The longer edges, of course, become the outer rim of the collector for your solar cooker, opening out to catch the sun.
Once put together, your solar cooker should look somewhat like a lampshade stuffed headfirst and at an angle into a box.
And there you have it!
Now that you have a general idea of how to make use of solar energy with your own solar cooker, we must confess the obvious - there are several intricate details in the process that can make building your solar cooker much easier and that will certainly vastly improve its overall effectiveness. But this article will hopefully have given you the knowledge and the confidence to see that you can do it, and it might be easier and cheaper than you had previously imagined.
[note to Mihai - feel free to add this if you wish (reworded in version 2 for your convenience: Return to this website for a forthcoming follow-up article "How to Use a Solar Cooker".]
