Electricity is a constant need in our society, which relies upon it for light, heat, and power to run a large variety of mechanical and electronic devices. Most of our current sources of energy, such as coal, oil, natural gas, and nuclear reactions, have been sustainable to date but produce pollution of one kind or another. Renewable energy resources, like wind, the sun, and moving water, don't create pollution, but they have their drawbacks - reliability, for one.
In this lesson, students work toward understanding the limitations of renewable energy resources if there is no system available for storing the energy. First, students watch a video segment on the engineering design process. Then they are challenged to design a storage system for renewable energy. They brainstorm and research ways in which renewable energies such as solar and wind power can be stored. Then students present their final designs. During this lesson, students should come to understand the steps in the engineering design process and how engineers design systems that convert energy from one form to another and store it for later use.
Note: This lesson can also be used in conjunction with the App Exception: phy03.sci.phys.energy.lp_energypr lesson plan. See Part II of this lesson.
- Understand the engineering design process (define the challenge, brainstorm and research solutions, choose a solution that fits within constraints, design and build a solution, test the solution, evaluate and redesign if necessary)
- Use system-level thinking to understand the transition from an energy resource to a usable, on-demand power source
Grade Levels: 6-8, 9-12
- Part I and Part II: one class period
- Part III: one class period
- Part IV: two class periods
- Part V (optional): one class period
- Part VI (optional): one class period
- Part VII: one half of a class period
- What Is the Design Process? QuickTime Video
- Windmill Gallery Flash Image
- Segway Technology: What's Newton Got to Do with It? QuickTime Video
- paper for diagrams
- poster board or large sheets of paper for presentations
- Optional: Windmill Worksheet (PDF) (PDF)
- Optional: assorted building materials, which can include string, wire, coat hangers, cardboard, card stock, paper, paper or plastic cups, straws, dowels, pencils, scissors, tubing, glue, masking tape, coins or weights, rubber bands
- Optional: fans or hair dryers
Before the Lesson
- Read the entire lesson plan and decide whether you would like students to complete the optional activities (Parts V and VI). If so, you will need to gather the necessary materials beforehand and plan your time accordingly.
- Make a copy of the Windmill Worksheet (PDF) for each student if you are doing Part V.
Part I: Define the Challenge
1. Tell students that they will be designing (and building and testing, if you decide to include Parts V and VI) models of a device that will store energy from wind so that it can be used on demand. Start with a discussion about the steps they might follow to design (and build and test) their models. Have students make a list of these steps, either as a class or in small groups. Then show students the video What Is the Design Process?. Compare and contrast students' lists with those in the video.
2. Have students write a description of the design challenge (for example, to design a model of a windmill that will convert its rotational energy from the wind into another form of energy that can be stored and then accessed on demand). This can be done either as a class or in small groups. Reiterate that defining the challenge is one of the engineering design steps.
Part II: Brainstorm and Research the Challenge
3. Tell students that they are now starting the brainstorming and research phase of the design process. Begin with a brainstorming session on what they already know about windmills. (If time allows, you can strengthen students' background knowledge of energy systems by doing the App Exception: phy03.sci.phys.energy.lp_energypr lesson.)
4. As part of their research, have students view theWindmill Gallery still collage. Encourage them to notice the similarities and differences between the structures. Get them to think about what types of things they must consider when designing their windmills.
5. Have students research ways that energy can be stored. This can be done individually or in small groups. The Internet provides a good resource for this work. Have them list at least two options for storing energy (for example, spinning flywheels, lifting weights, pumping water uphill). For each they should:
- Describe how they would develop a system to convert energy from the windmill rotation to the stored form of energy (kinetic to potential energy);
- sketch a picture of what it would look like; and
- explain how they would then access that energy when needed.
Part III: Choose the Solution
6. At the beginning of class, review the "Brainstorming" and "Design a Solution" sections of the video What Is the Design Process? with the students. Then have students finish their brainstorming and research. By the end of the class, each group should have chosen the solution that they are going to pursue from their list of options. (Note: Information about the other options should be kept for reference.)
Part IV: Design and Sketch the Solution
7. Working in their groups, have students draw detailed diagrams that show all the parts of their system. Each part should be labeled and its dimensions given. Review why this is important to do accurately.
8. Next, have students prepare a presentation of their final concept, including information about designs they ruled out and why. Note: If time allows, you can have students build their systems to use as a visual aid for their presentations. See Part V.
9. Have each group give the presentation developed as part of the design phase. (If students constructed their own models in Part V, they should use these for the presentation.) Tell students to provide the following information:
- why they picked this design for their structure
- the forms of energy at different points in the system
- how long they think the energy can be stored without loss
Part V: Build the Solution (Optional)
10. If you choose to have students build their systems, let them know beforehand what materials you have available for them to use. If they would like to use any additional materials, suggest that they bring them. Make clear to students that they should build simple models that they can refer to as they explain the concept (see Step 9); these are models to demonstrate a concept and refined processes are not necessary. If time permits, they can build actual working models.
11. Distribute copies of the Windmill Worksheet (PDF) to students and have each group select materials with which to construct the model of their windmill and energy storage system. Have them build the structure to scale. Encourage students to share the tasks and work collaboratively on the building process.
Part VI: Test and Evaluate the Solution (Optional)
12. Review with the students the "Test Ideas" and "Evaluate" sections of the video What Is the Design Process?.
13. Have each group of students test their structure by blowing air on it. A constant wind source, like a fan or hair dryer, works best, but students can also simply blow air on it with their mouths. After a few minutes, ask students to stop blowing air on the models and consider the following questions:
- Does the structure tip over or remain standing?
- Is the energy conversion accomplished?
- When the air stops blowing, what happens to the system?
14. Have students evaluate the results of their tests. They can discuss what they might do differently next time, and consider the following questions:
- What were the limits of your model?
- Were there any steps in the engineering design process that you felt were more important than others? Why?
15. If time allows, you can extend the activity as follows:
- Focus on the effect (if any) of different wind strengths. Students can use the high- and low-speed settings of a fan or hair dryer to test this. How do designs take wind strength into account?
- Draw new diagrams to illustrate possible design modifications they would incorporate after testing.
Part VII: The Segway
16. To conclude the lesson, show the videoSegway Technology: What's Newton Got to Do with It? In this technology, the energy source must be compact and reliable. Ask:
- What is the advantage of having a rechargeable energy source?
Check for Understanding
Discuss the following:
- How have engineers solved some of the energy storage problems that exist in the world? (wind farms, solar energy, etc.)
- What are the steps of the engineering design process?
- Even systems that didn't transfer energy very well taught us something. What did you learn from going through this process (or from watching other students' examples/models)?
- How were your group's design and/or structure similar to or different from other ones in the class?
- What would you do to make it more effective (operate more efficiently and/or store more energy) in your next design?