LESSON PLANS
Here Comes the Sun
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This lesson explores the concept of how solar energy is gathered by solar panels and adapted to provide power to a variety of machines, from calculators to spacecraft. Students disassemble a solar powered calculator and explore the component parts. Students work in teams to suggest design enhancements to the calculator to improve performance.
Age Levels: 8-18
Required Materials
Design Challenge
You are a team of engineers given the challenge of disassembling a solar powered calculator and exploring the component parts. You’ll then study the solar panel and see how it is connected to the other parts of the calculator. As a team, suggest design enhancements to the calculator to improve performance.
Criteria
Constraints
Student Reflection (engineering notebook)
How do you think your new design will impact the cost of this calculator? Why?
The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.
How Solar Panels Work
Solar Panels are Used Everywhere!
Solar panels work by converting the energy of the sun into electricity. This is used to power many products on earth and support power on spacecraft too. In this lesson we are working with solar powered calculators, which have been a simple but effective application for many years. If you look carefully, you will find many applications in your town or school including stoplights and road signs. You may even have decorative solar powered lights in your yard to help guide you safely at night. As solar technology advances and becomes more efficient, the applications for solar power continue to expand. Solar phone chargers, like the one to the right, help hikers keep in touch which can be lifesaving in an emergency.
Flexibility
Solar panel can now be flexible which helps with building design and opens all sorts of applications not available ten years ago. The illustration below depicts a flexible solar panel powered bus stop which would allow those waiting to charge their phones, have lighting after dark, and potentially communicate bus arrival schedules or delays.
What is a Simple Circuit?
A simple circuit consists of three minimum elements that are required to complete a functioning electric circuit: a source of electricity (battery),a path or conductor on which electricity flows (wire) and an electrical resistor (lamp) which is any device that requires electricity to operate. The illustration below shows a simple circuit containing, one battery, two wires, a switch, and a bulb. The flow of electricity is from the high potential (+) terminal of the battery through the bulb (lighting it up), and back to the negative (-) terminal, in a continual flow when the switch is in the on position so current can flow.
Schematic Diagram of a Simple Circuit
The following is a schematic diagram of the simple circuit showing the electronic symbols for the battery, switch, and bulb.
Internet Connections
Recommended Reading
Writing Activity
Write an essay or a paragraph describing how solar panels have been engineered into a product you find in your home or school. Explain why solar energy is a good choice for powering this product.
Note: Lesson plans in this series are aligned to one or more of the following sets of standards:
CONTENT STANDARD A: Science as Inquiry
As a result of activities, all students should develop
CONTENT STANDARD B: Physical Science
As a result of the activities, all students should develop an understanding of
CONTENT STANDARD E: Science and Technology
As a result of activities, all students should develop
CONTENT STANDARD A: Science as Inquiry
As a result of activities, all students should develop
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop an understanding of
CONTENT STANDARD E: Science and Technology
As a result of activities in grades 5-8, all students should develop
CONTENT STANDARD A: Science as Inquiry
As a result of activities, all students should develop
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop understanding of
CONTENT STANDARD E: Science and Technology
As a result of activities, all students should develop
Students who demonstrate understanding can:
Engineering Design
Students who demonstrate understanding can:
Engineering Design
Students who demonstrate understanding can:
The Nature of Technology
Technology and Society
Design
Abilities for a Technological World
The Designed World
Dissect a Solar Powered Calculator
Step One: As a team, observe whether the calculator operates when you completely block the solar power panel. What happens if you partially block the solar panel? Write you observations, and explanations of what you found below.
Step Two: Suggest five other products you can think of that are either completely or partially powered by solar panels.
Step Three: As a team, disassemble either a new (inexpensive) or old unusable solar powered calculator, using the materials provided to you. Be sure that you remove all the small screws that hold the top and bottom together, some are often hidden under pads or rubber strips. You will need to use a very small screwdriver, such as the type commonly found in eyeglass repair kits. And, you will need to unscrew the circuit board from the front panel of the calculator too — there are many screws.
Safety Note: Be careful touching the solar panel and the LCD (liquid crystal display) as the glass edges may be sharp.
Step Four: As a team, observe the solar panel and see how it is connected to the other parts of the calculator. Examine all the other parts of the calculator, and discuss what you find. Then answer questions below.
Questions:
1. How many individual parts did you find? Describe them.
2. What surprised you the most about the interior parts of the calculator?
3. How was the solar panel connected to the circuit board?
4. If there was a battery back up for this calculator, how was it connected to the circuit board?
5. Some calculators will still operate in the disassembled state, as long as the wires from the solar panel and battery are still connected to the circuit board. Does your calculator still operate? If you reconnect the wires with scotch tape, does it still work?
6. Why do you think there was a rubber or plastic sheet separating the circuit board from the buttons you press?
7. What type of material do you think is embedded under the plastic or rubber sheet and the circuit board? Why do you think engineers included this sheet in their design?
8. Assuming you could repower your calculator, if you reconstructed your calculator with all the buttons in different positions, would it still work properly? Why, why not?
9. Is there anything you would recommend, as part of an engineering team, to improve the functionality of the calculator you disassembled? Attach a drawing or sketch of your proposed component part or improvement, and answer the questions below:
What new materials will you need (if any) |
What materials or parts will you eliminate (if any) |
How will this new product improve the functionality of a calculator? |
How do you think your new design will impact the cost of this calculator? Why? |
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5. Present your ideas to class.