Hands-on Activity Chasing the Sun

Learning Objectives

After this activity, students should be able to:

• Explain how and why a sunflower follows the sun.
• Describe the sequence the sun travels through the sky throughout the day.
• Discuss ways to maximize sun exposure for a solar panel.
• Engineer a stand that allows their “solar panel” to follow the path of the sun.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

State Standards

Materials List

Each group needs:

• 10 pipe cleaners
• 2 x 3” piece of cardboard (solar panel model)
• foil, to cover the cardboard and to represent the panel modules (optional)
• pair of scissors
• anything at their desk (textbooks, folders, etc.)

For each student:

• writing or drawing utensils

For the entire class to share:

• a flashlight (representing the sun)

Worksheets and Attachments

Pre-Req Knowledge

• Familiarity with the engineering design process and its steps.
• Familiarity with solar patterns such as how the sun travels through the sky during the day.
• Knowledge on how the sun’s energy has different benefits like helping plants grow.
• Knowledge of cardinal direction

Introduction/Motivation

[Show an image of a solar panel.] What do you think this is? (Let students offer answers.) What do you think this has to do with the sun? (Let students offer answers.) Solar panels convert the sun’s photons into electricity as they excite the electrons found in the solar panels.

(Show this video, How Solar Power Works: https://www.youtube.com/watch?v=hw2_hEMgE4o)

What do you notice about these solar panels?  (Students should  discuss what they think the issue might be based on what they know about solar patterns and solar panels. Point out the solar panel’s position in relation to the sun and ask the students why this might be a problem. Lead students toward the fact that the solar panels are static/stationary but the sun moves across the sky. Have students draw the conclusion that the solar panels are not facing the sun during all times of the day.) One of the main problems with solar energy is that it can be difficult to maximize its efficiency as a green alternative because of its need for direct sunlight. How do you think we can improve these solar panels? (Students should conclude that this is a problem because this means the solar panels only get a limited amount of sun exposure and thus less potential solar energy to turn into electricity.)

What else besides solar panels needs lots of sunlight? (Lead students to plants also needing lots of sunlight to grow.)  Do you know that sometimes engineers turn to nature for inspiration? There is one plant that engineers can look to that might be the solution to the problem of the sun moving throughout the day. Let’s check out this video. (Show this video: Why sunflowers follow the sun: https://www.youtube.com/watch?v=1gaWrMCiZR8)

What did you see the flower doing in the video? Why do you think it is doing that? How do you think we can apply the sunflower solution to the problem they have with the solar panels.? (Since the goal is to have the solar panel follow the sun to optimize its sunlight exposure, let’s think about how we can design a set of panels to help solve this problem.

Procedure

Background:

Solar panels convert the sun’s photons into electricity as they excite the electrons found in the solar panels. One of the main problems with solar energy is that it can be difficult to maximize its efficiency as a green alternative because of its need for direct sunlight. After research on how sunflowers bend and turn to maximize sun exposure to help them grow, students should be able to independently discover what benefits a moving solar panel would have.

The problem the students are solving is the sun moves across the sky, but solar panels remain stationary. The goal is to design a prototype solar panel that “follows” the sun to optimize its sunlight exposure. Theoretically students will apply what they learned about the sun flowers to help solve this problem. Use the Solar Patterns Presentation and the Solar Energy Effects Presentation to help guide planning and discussions.

Before the Activity

• Gather materials for each group in bins: 2 x 3” cardboard (for the solar panel) 10 pipe cleaners, 1 pair scissors, foil (optional) for the panel modules.
• Make student copies of the Solar Stand Procedures Worksheet and the Solar Panel Design Worksheet.
• Make desired teacher copies of the Teacher Assessment Checklist, Presentation Rubric.
• Before passing out materials, explain to students what materials they will be using and how to use them safely as an engineer would.
• Demonstrate how to cut a pipe cleaner safely.
• Show the Solar Stand Procedures Worksheet and the Solar Panel Design Worksheet and explain how they will use it to record their engineering iterations and observations.
• Set partner work expectations for students and remind them how engineers effectively communicate and collaborate.
• Practice collaboration expectations if needed for 1- 2 minutes.

With the Students

1. Go through the Introduction/Motivation section.
2. Pass out the Solar Stand Procedures Worksheet and the Solar Panel Design Worksheet and have students put their names on it.
3. Have students group up with their partners.
4. Pass out material bins: 2 x 3” cardboard (solar panel), 10 pipe cleaners, pair scissors, foil (optional).
5. Remind students their goal is to work together to create a solar panel stand that maximizes sun exposure.
6. Set a timer for 10 minutes on the board and let students explore the materials and try to construct their panels.
7. Possible methods for construction:

• Wrapping the pipe cleaners around each other to create a bendable stand for the solar panel.
• Creating a panel of solar modules that use pipe cleaners to move back and forth.

8. Circulate the room and prompt students to try different materials or work together using their collaboration expectations as needed.
9. When the timer goes off, prompt students to stop where they are at for a collaborative check-in.
10. Walk around the room with a flashlight and mimic the sun's path throughout the day to test each design. Have students walk around the room and observe each group's design test.
11. Prompt students to discuss why their designs worked or why not and what they could change.
12. Give students an additional 10 minutes to reiterate their designs.
13. When the timer goes off, prompt students to organize their work station/put away materials.
14. Put a 2 minute timer on the board for this transition.
15. Go over the Presentation Rubric with students.
16. Go over the Presentation Script Worksheet with students. Read it out to the class and prompt each group to fill in along the way.
17. Put a 2 minute timer on board to practice for the presentation.
18. Have groups present their inventions and evaluate.
19. Hold a post presentation discussion.
20. Prompt students to share strengths and weaknesses of their designs. Prompt students to discuss similarities and differences.

Vocabulary/Definitions

atom: A tiny particle (that you cannot see) that makes up matter.

axis: An invisible line around which the earth rotates.

electricity: When electrons move.

electron: A tiny particle with a negative charge that is part of an atom.

matter: Anything that takes up space.

rotate: To spin around itself.

solar energy : Light and heat energy from the sun.

solar panel: A tool used to convert sunlight into electricity.

Assessment

Pre-Activity Assessment

To assess student background knowledge on solar patterns:

Students answer The Sequence of the Sun Writing worksheet to describe the path the sun takes throughout the day. Students describe the position of the sun at the beginning, middle and end of the day using the sentence starters. (Younger students can use The Sequence of the Sun Drawing worksheet instead.)

Activity Embedded (Formative) Assessment

To assess students understanding of solar patterns and solar panels during the activity:

Observe students' creation of solar panel stands. While doing this they can use the Teacher Assessment Checklist check off for student understanding. Students demonstrate understanding when they can accurately describe if their prototype is maximizing sun consumption and how they know. (For example, they might say “Yes, because the stand can move to follow the sun” or “No, because the solar panel can only face this way without falling”. This provides the ability to see if students understand what motion their stand will have to make to mimic the sun's path after the research portion of the process and gives room for them to correct misconceptions and prompt students to reiterate their design as needed.)

(Optional) To assess students understanding of engineering design process:

Use the Teacher Assessment Checklist to check off for student understanding. Students demonstrate understanding of the engineer design process by being able to tell what part of the process they are currently in throughout the lesson.

To assess ability to design reiterations:

Use the Teacher Assessment Checklist to mark off students who iterate their designs. Prompt to share during presentation what they tried and changed or what they would change to improve their design. For example, you could ask students when they are sharing their design which parts of their design contributed to maximizing solar consumption. You can then prompt them to share what they think they could do to improve their design based on this.

Collaborative work/ Feedback: Use the Teacher Assessment Checklist to mark off students observed using collaborative techniques and participating in providing critical feedback using the compliment sandwich model provided throughout the activity.

Post-Activity (Summative) Assessment

Presentation Rubric: After concluding the activity, each group finalizes their notes and present their findings to the class. Use the Presentation Rubric for the students' presentation of their findings. Each student's presentation should include a summary of their engineering design process (including possible iterations), how they know their tool was maximized sun exposure and a demonstration of how their solar stand works.

(Optional) Presentation Script: Once students have concluded the activity, present the sequencing Presentation Script. This “First, Next, Then, Finally” script helps students meet the presentation rubric requirements by having them write out what they did first when building, if their design worked and what they did next to reiterate. Prompt each student group to fill in the blanks of the sequence writing script as they go through it as a class.

Investigating Questions

Why would the sunflower follow the sun? (It follows the path of the sun for optimal sunlight.)

What else is something you know that needs lots of sunlight like a solar panel? (Plants, trees, flowers, etc.)

How can engineers use nature to help them solve problems? (Answers may vary.)

Safety Issues

• Students may use scissors to cut pipe cleaners. This should be demonstrated during review of how to use materials safely and supervise.
• Students will be using pipe cleaners which can have sharp tips. Demonstrate how to maneuver a pipe cleaner during review of how to use materials safely and supervise.
• Some students may want to poke holes in their cardboard with pencils or scissors. Demonstrate how to do this safely if need arises.

Troubleshooting Tips

After the first build, have students circulate to observe the test of all designs so you can facilitate a discussion on what worked and what did not. The biggest problem that was observed the first time is that the stands did not stand up by themselves. Including a discussion on how students think they could solve this problem before the next build could assist in the issue. Remind students they can also use any of the supplies at their desks to help anchor their designs.

Activity Extensions

Published Procedure Paper

Once all students have engineered a successful prototype the teacher can have students write up their procedures just like engineers would in real life to publish for others to learn from. The teacher will prompt students to describe the sequence in which they built their design. If desired the teacher could have groups swap procedures to see if students can replicate designs based on the procedures written and discuss how papers are often peer reviewed. After the initial swap groups can provide each other feedback and rewrite for clarity.

Activity Scaling

To support lower grades and younger students in carrying out this activity the teacher can have them complete the drawing templates rather than the writing ones to allow them to focus on the engineering. You can also have them verbally complete the optional presentation script rather than write it.

To support upper grades, older students and more advanced students the teacher can extend the content knowledge used and even introduce more materials or complex designs into their prototypes. For example, they can discuss that the reason the sunflower follows the sun has to do with photosynthesis. They could also have students further apply their knowledge on how sun exposure changes with the seasons to challenge them to further adapt their solar panel to combat such changes. Finally, they could also further challenge their writing and comprehension skills by having them create the published procedures paper and swapping these papers to see if other groups can replicate their prototype from the methods provided. This will challenge students to have to be clear and concise just like real engineers do in the methods/ procedures sections of their papers.

Additional Multimedia Support

Before activity:

• Earth’s Rotation: https://www.youtube.com/watch?v=l64YwNl1wr0
• The Sun: https://jr.brainpop.com/science/space/sun/
• How do solar panels work?: https://www.youtube.com/watch?v=hw2_hEMgE4o
• Sunflowers solution: https://www.youtube.com/watch?v=1gaWrMCiZR8

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