Use solar energy to reduce energy bills and for convenience. A solar cooker is handy on camping trips and RV or boat excursions, because it provides a passive option to prepare food using sunlight. A shoebox solar oven or cooker is easy to build using common household materials. The sun's rays are captured in the cooker, resulting in a temperature of 250 degrees Fahrenheit or more.
Preparing the cooker
Measure a rectangle 1 inch from the edges of the outside of your shoebox lid. Cut three sides of the rectangle, leaving one longer side uncut. If desired, score the fourth side of the rectangle on the inside of the lid, to make lifting and propping up the rectangle easy. The lid can later be positioned to best capture the sun's rays.
Creating a reflective interior
Line and glue aluminum foil to the inside of your shoe box, shiny side out, making sure no cardboard is exposed. If desired, add a second layer of foil. Line the inside of the lid and the flap with foil similarly (make sure the flap is lined separately and can be lifted up). The foil will reflect the sunlight and direct it to the cooking area,.
Line the sides of the cooker with black paper
Measure and cut pieces of black construction paper to fit the inside walls and bottom of the shoebox. Glue these pieces to the aluminum foil lining. The dark color will absorb the sun's rays, increasing the interior temperature.
Attach translucent plastic to the lid
Measure and cut the transparent plastic to be slightly larger than the rectangle previously cut out of the lid. Tape the plastic to the inside of the lid to cover the rectangular cutout. The plastic will trap the heat inside the box. Prop the foil-lined rectangle on the lid open and hold it open using metal wire or bamboo sticks placed at the corners. Place your food, in cookware, inside the shoebox and put the lid on top. Position your solar cooker where it will get the most exposure to sunlight. Cooking time will vary depending on the food and the weather.
TL;DR (Too Long; Didn't Read)
Consider using a larger box that will accommodate a small pot or tray.
Contents of the solar cooker will be hot, so use protective mitts when removing cookware.