Making a Solar Cooker (For Guardians)

By Morgan Turano, science editor

This Activity

In this activity, students will build their own solar cookers using a cardboard box, plastic wrap, and tape, with a little help from you. Students will test their solar ovens to confirm that sunlight plays a key role in this process, then modify their solar ovens to increase the internal temperature. With permission from you, students can then use their modified solar cookers to make s’mores.

All of the instructions for building, testing, and modifying the device are found in the student section of this handout; sample answers can be found below in the guardian section. While normally in scientific settings temperatures are recorded in Celsius, for the purposes of this experiment temperatures will be recorded in Fahrenheit because this is the unit of measurement for most U.S. thermometers.

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Share a student version with your child.

STUDENT VERSION: Check out the student-facing version along with a printable version you can give your student.

Time

The activity is broken into four 30-minute parts which are designed to take place on up to four different days depending on your availability and needs. While Parts 1 and 2 can be performed in any weather, we recommend Parts 3 and 4 be performed on warm, sunny days.

Background Information

Cars parked in direct sunlight in summer can get much hotter inside than the temperature is outside. This is because the windows allow the sunlight to enter the car, where the light is converted to heat energy, and the closed doors and windows prevent the heat from leaving. Over time, the temperature continues to increase, even while the external temperature stays relatively cool.

The same principle can be applied to create a device that will heat food. This can be accomplished using a cardboard box by adding plastic windows and ensuring the box is closed to prevent heat from escaping. This is known as a solar cooker or solar oven.

Standards

This lesson addresses the following Next Generation Science Standards (NGSS) for Grade 4:

• 4-PS3-2: Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents
• 4-PS3-4: Apply scientific ideas to design, test, and refine a device that converts energy from one form to another.
• 3-5-ETS1-1: Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
• 3-5-ETS1-2: Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
• 3-5-ETS1-3: Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

Please note:

• Solar cookers can become very hot inside. Adults should handle and open the cooker carefully to ensure student safety.
• Solar cookers should only be used for warming and melting foods, not for cooking raw foods such as meats or eggs.

Sample Answers

Experiment A: In the Dark Data

Note to Guardians: The values in this table will be determined by the students’ own measurements; the values below are examples only and are used to calculate the answers to the questions that follow.

	Starting	After 1/2 Hour
Temperature in Area (°F)	73	74
Temperature in Solar Cooker (°F)	73	74
Appearance of Food	normal	still normal

 

1. Yes, the temperature changed 1°F.
2. Yes, the temperature changed 1°F.
3. The temperature changes were the same.
4. 73 – 73 = 0; 74 – 74 = 0
5. No, the chocolate stayed the same. It didn’t melt because the temperature didn’t change much.

Experiment B: In the Sunlight Data

Note to Guardians: The values in this table will be determined by the students’ own measurements; the values below are examples only and are used to calculate the answers to the questions that follow.

	Starting	After 1/2 Hour
Temperature in Area (°F)	75	77
Temperature in Solar Cooker (°F)	75	84
Appearance of Food	normal	melty

1. The temperature in the area increased by 2°F.
2. The temperature in the solar cooker changed by 9°F.
3. The temperature change inside the solar cooker was greater.
4. 75 – 75 = 0; 84 – 77 = 7
5. Yes, the chocolate melted. It melted because the temperature was much higher.

Analyzing the Data

Note to Guardians: The answers to the questions that follow are the expected answers but could differ based on the students’ own data.

1. The temperature in the solar cooker was hotter after a half hour in the sunlight.
2. The solar cooker that was in the sunlight had the greater temperature change.
3. The solar cooker in the sunlight had the higher temperature.
4. The solar cooker in the sunlight had the larger increase in temperature.
5. Yes, because the solar cooker in the sunlight got hotter and the one in the dark did not.
6. light