6th Grade Physical Science
8th ANNUAL SOLAR COOKER CHALLENGE
WHO: All 6th grade; work in teams of 2 to 4 students; building may be team or individual.
WHAT: Design and build a solar oven and test it in the Solar Cooker Challenge
WHEN: Background and engineering design process—Sept. 18-Oct. 30
Cooking Day—Friday, November 6 (weather permitting), set-up in a.m.
GOAL: Cook chopped apples to tender stage using only heat from solar radiation.
Solar ovens can be efficient cookers. They are even used in some countries to purify water or sterilize
medical instruments. On cooking day we’ll cook apples (chopped apples, cinnamon, and sugar).
CONSTRAINTS:
Temperature—Recipes for baked apples list oven temperature at 350oF. However, chopped apples
cooked to al dente tenderness at an internal temperature of 150oF. Therefore the target temperature
will be 150oF (66oC). Temperature will be measured with a laser thermometer; it won’t touch food.
Size—Maximum size 90cm x 90cm x 90cm. Minimum size must hold a bowl 14cm diameter.
Materials—The following is a partial list of materials. Most are readily available without need for
special purchase. Any unique materials brought from home require teacher approval.
 Structure—cardboard, foam core
 Glazing—plastic or acetate sheets [glass strongly discouraged]
 Insulation—paper, foam, bubble wrap or similar commonly available material
 Fastening and sealing—Any commonly available type of tape; duct tape best choice
Optional features—Special features other than those below require teacher approval.
 Reflectors—Not required. Foil, mirrors [glass discouraged], or metal [cover any sharp edges]
 Interior containers—Not required. Chopped apples will be approximately ½ cup. If design
includes an interior container built by students or brought from home, care must be taken to keep
the container clean since students will be eating the apples.
Costs—Students must list all materials used. In evaluating designs, special credit will be given for use
of free and/or recycled materials. Students are discouraged from purchasing expensive or exotic
materials for their cooker.
Family involvement—Family members may assist in the actual construction of the solar cooker, but
the design should be the student’s. The bulk of the work should be done by the students.
TIMELINE AND DEADLINES—The following will be covered in science lab (Th-F):
Sept. 17-18—Introduce Solar Cooker Challenge; electromagnetic spectrum & solar radiation
Sept. 24-25—Heat transfer—convection and conduction
Oct. 1-2—Electromagnetic radiation; heat absorption & emissivity; heat sinks
Oct. 8-9—Maximizing heat gain, minimizing heat loss; observe solar-heated swimming pools;
build insulation systems for soda cans; test cans outside classroom during week; collect data
Oct 15-16—Analyze data from insulated soda can and solar pool experiments
Oct. 22-23— Solar oven demo; Sun declination; dimensioned drawings how-to; preliminary designs
Oct. 29-30—Detailed, dimensioned designs due; design charrette; improve/incorporate new ideas
Nov. 6—Set up solar cookers in quad during morning; record internal temperatures all day;
eat cooked apples at end of school day
Nov. 12-13—Completed project documents due, including as-built drawings and performance data
BACKGROUND AND DESIGN IDEAS:
To do this project, you should understand these terms and concepts; most will be covered in lab:
 solar energy
 radiant heat transfer
 convective heat transfer
 insulation
 heat sink
Here are some questions to think about and research when designing your cooker:
 How can you maximize the heat collection?
 How can you minimize heat loss?
 What is the best angle for the opening? What direction should the cooker face?
 How will you hold the cooker in place if it is windy?
Use the examples below as inspiration to come up with your own design for a solar cooker.
PIZZA BOX SOLAR OVEN
Cut 3-sided flap in top
of box.
Cover inside of lid with
foil. Tape plastic wrap
over opening.
Diagrams from lesson adapted by Kai-Mei Fu and Michael Preiner
at www.stanford.edu/group/sciencebus/
Line bottom of box with black
construction paper. Fill space
around edges with newspaper or
other insulation.
Place food in box. Close lid.
Prop up flap. Orient box so
that sunlight is reflected by foil
onto the food inside the box.
BOX WITHIN A BOX SOLAR OVEN
From Engineering Spot website at http://www.edunewz.com/2007/07/now-youre-cooking.html
To the left is a picture of a type of efficient, easy-to-build solar oven. The design is a box within a box.
At the bottom of the inner box, there is a foil-covered shelf, painted black. The shelf serves two purposes.
First, it holds the cooking pot. Second, it acts as a "heat sink." The shelf absorbs direct and reflected sunlight,
which warms it. It then radiates the heat, warming the inner box. [Why paint the oven shelf black? Why use a
black cooking pot?] The plastic window holds the heat in, as does the insulating air space between the inner
box and the outer box.
PANEL AND PARABOLIC SOLAR COOKERS
Plans available at The Solar Cooking Archive website at http://www.solarcooking.org/plans/ .
Solar Funnel Cooker
Reflective Open Box
Solar Cooker
Dublin, Ohio class cooker