Solar Ovens-Part 1

ObjectiveThis is a two to three part lesson that builds on itself.

  • The first lesson discusses the reasons to cook using the sun. Solar ovens are built from shoeboxes.
  • The second lesson asks the students to finish their oven and apple slices are baked for several hours. Discussion about the requirements for successful cooking with a solar oven. The results of their experiment are recorded.
  • The third lesson asks them to improve upon their previous design and increase the efficiency of their oven. Results from this experiment are quantified and compared to the previous lesson.
  • The last component, though not an actual lesson, was to use the ovens to bake cookies (coincided with the last week of class).

CA Standards--Third Grade

Materials

Start trying to collect shoeboxes for the entire class at least 2-3 weeks prior to the lesson. This could work if you had 2 kids with one oven but conflict may arise over ownership when the unit is completed. I used instructions from the No Doubt Learning site with some modifications.

  • Shoeboxes with lid, aluminum foil (heavy duty and regular), plastic wrap
  • Tape, stapler, scissors
  • Black construction paper, newspaper
  • Toothpicks, straight pin or push pin

Procedures

  1. Started by discussing why one would want to use the sun to cook.
    • Good for the environment, readily available in many climates, keeps your house cool in the summer, doesn’t require fire/fuel, etc.
  2. Cut a 3-sided rectangle in the lid of the box. Some kids will punch a hole and then saw at the box with one side of their scissors; others have enough hand strength to cut the box. Leave a one to three inch margin on 3 sides of the rectangle. One edge of the rectangle should incorporate the crease in the top lid. This is your reflector flap. Students may cut directly through the rim or lip in the lid to make the rectangle. The cut in the lip can be repaired using staples.
  1. If there are any holes in the box, tape foil or black paper over them.
  2. Line the bottom of the box with a rectangle of heavy duty foil. The foil should cover the area under the hole in the lid. Make sure that the reflective side faces upwards. If there are any gaps between the foil and the sides, those extra spaces can be filled in with bunched up newspaper to act as insulation.
  3. Apply foil to the flap on the lid. Make sure that the reflective layer faces the inside of the box.
  4. Cover the top of the box, not incorporating the reflector flap, with a smooth layer of plastic wrap. Make sure to get the wrinkles out, then tape down to the top of the box.
  5. Make a little support for your reflector flap using a toothpick. Poke a hole using a straight pin into the top of the lid near the flap hinge then replace with a toothpick to hold the reflector flap open.

**The majority of students only got through step #4 for the first lesson so we finished the next session (see Solar Ovens--Part 2).