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.
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.
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 the Windmill 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:
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.)
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:
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.
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:
14. Have students evaluate the results of their tests. They can discuss what they might do differently next time, and consider the following questions:
15. If time allows, you can extend the activity as follows:
16. To conclude the lesson, show the video Segway Technology: What's Newton Got to Do with It? In this technology, the energy source must be compact and reliable. Ask:
Discuss the following: