+ Level Elementary Grades K-4 WIND TURBINE DESIGN AND TESTING ©2014 National Geographic Society. All rights reserved. Society. Geographic National ©2014 Artville Image credit: ACTIVITY: WIND TURBINE DESIGN AND TESTING Big Idea Students will learn how the power of the wind is harnessed and used to make electricity. Guiding Question How do engineers create useful power from the wind? Materials Gathered by Teacher 1. Fan 2. Scrap stiff paper (e.g. card stock, cardboard cereal boxes, etc.) 3. Scissors: 1 pair for every 4 students (Most students in elementary classrooms have scissors or the teacher has a classroom set.) 4. Clear or masking tape: 1 roll per classroom 5. Projector: a way to share the online video Materials Provided in the EITC Kit 1. Motor (2 per kit) 1. Electrical wires (2 one-foot red wires and 2 one-foot black wires) 1. Alligator clips (8 per kit) 1. LED Bulb (2 per kit) 1. Corks (1 per group) 2. Toothpicks (10 per group) Set Up Communicate with the teacher at least one week before your scheduled classroom visit. Inform the teacher that this activity will require an indoor workspace. For the indoor portion of this visit, desks should be arranged so students can alternate between small-group work and all-class discussions and demonstrations. For the complete activity and www.classroomengineers.org Page 1 of 8 media resources, please visit: Level Elementary Grades K-4 + WIND TURBINE DESIGN AND TESTING Introduction Teacher introduces the engineer/classroom visitor. Setting the Stage • Show the introductory video • Tell students who you are, what you do, and what it’s like to work in your career (3 minutes). ©2014 National Geographic Society. All rights reserved. Society. Geographic National ©2014 • Tell them a story about how you got interested in engineering/your career or something that happened in your work that was really exciting—something that truly made a difference in your life (3 minutes). • Ask students if they know what a wind turbine is. Allow time for as many responses as possible. Then you can tell students that a wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity. • Show a wind turbine video clip. Hands-on Activity Briefly discuss students’ prior knowledge of sources of electricity and how wind energy works. Ask: Have you ever wondered how the wind is used to make power for our homes and cities? Tell students that wind turbines are marvels of engineering (amazing machines), but the idea of using the wind to produce power started thousands of years ago as simple machines much like what they will be building today. Briefly explain that air currents (flowing air) on Earth naturally create wind. Think about a time when you have stood outside on a windy day and your body felt the power of the wind. Since the first century a.d. or earlier, humans have invented machines to use wind power. Modern wind turbines have blades half the length of a football field to use as much wind power as possible. The spinning blades connect to a generator to create electricity for us to use. A generator is a machine that makes electricity. Ask: If the wind is constantly changing, how do wind turbines keep making power? Explain: Because most wind turbines are very large, small changes in the wind have little effect on the wind turbine. For large wind changes, wind turbines can be adjusted to keep them spinning at the correct speed. The wind turbine has sensors that tell the onboard computer the wind speed and wind direction. A sensor is a device that detects or senses heat, light, sound, motion, etc. The computer can turn the entire wind turbine head to face the direction of the wind. As the wind blows lighter or stronger, the angle of the blades, known as pitch, can be changed to help the turbine spin faster or slower. If the wind is blowing really strong, a brake keeps the turbine from spinning too fast. Lockheed Martin measures the wind very accurately to find the best places to build new groups of wind turbines, known as wind farms. Wind farms are places where the wind blows consistently and are able to produce the most energy from wind turbines. Students design and make wind turbine blades. Explain to students that they are going to design and build a turbine rotor, which is the part of the wind turbine that spins with the wind. They are going to decide the size, shape, and pitch of their blades as well as the number of blades to connect to their cork. The rotor will be connected to a simple generator and held in the fan-generated wind. As the rotor spins, the generator will create electricity to light an LED light bulb. Ask the teacher to divide students into groups of three. Ask one or more student volunteers to pass out materials to each group including 1 pair of scissors, 1 cork, tape, toothpicks, and stiff paper for the blades. Advise students that they can cut blades into the shape of the template or another shape of their choosing. Demonstrate cutting out a blade and using it as a template for cutting the next blade the same size. Tell students it’s important that once they select a blade shape and size, the rest of the blades need to be nearly identical. Then demonstrate taping a blade to a toothpick. Explain that once the blades are cut out, students will tape each blade to a toothpick. Once all of the blades are mounted on toothpicks, press the toothpicks into the cork with each blade having approximately the same pitch (angle). Explain and demonstrate that students should try to make the turbine as symmetrical as possible. This makes the turbine more balanced and helps it spin faster. For the complete activity and www.classroomengineers.org Page 2 of 8 media resources, please visit: Level Elementary Grades K-4 + WIND TURBINE DESIGN AND TESTING Students test their wind turbines. As groups finish assembling their wind turbine rotors, call them up to the fan to test their creations. You or the teacher will press the axle of the motor into the cork as near to the center as possible. Ask one student to hold the motor and face the turbine toward the fan (wind). The other students will hold the LED bulb and observe the amount of light generated. After each test, disconnect the rotor from the motor shaft and let the groups try to modify (change) their rotors to work better; try using more/fewer blades, smaller/larger blades, more/less pitch angle, and better balance. Each group should be able to test and modify their turbine 2 to 3 times. Ask students to write down how their changes affected the results. Did the turbine look like it spun faster or slower? Did the light look brighter or dimmer? ©2014 National Geographic Society. All rights reserved. Society. Geographic National ©2014 Wrap-Up Have students bring the leftover material to the front of the room and place it in the appropriate location. While the materials are being put away, make a table on the white board and label the top row with the group numbers (see example of chart in the resource carousel). Once students have all returned to their groups, ask group 1 how many blades their first wind turbine design had and write the number under the group 1 column. Next ask group 1 what they changed when they modified their design using as few words as possible (e.g., changed blade pitch, number of blades, made it more symmetrical, made blades smaller/larger). Ask them which design worked the best and put a star in that row (see example chart in the resource carousel). Do this for the remaining groups. Ask students questions about what they discovered about designing and building windmills. How many blades did most groups choose? Did more or less pitch work better? Did smaller or larger blades work better? How important was symmetry and balance? Explain that symmetry is when one shape becomes exactly like another if you flip, slide, or turn it. Emphasize that what worked best in the experiment was specific to the test conditions. To design real wind turbines, engineers must consider many things. Ask students to name examples of what they would have to consider when designing a real wind turbine for a specific location. Students should come up with most of the following criteria. When they have completed their list, offer them the examples they did not mention: • The normal wind speed • The maximum wind speed • How far the wind turbine will be from where the electricity will be used • How big the wind turbine blades can be without breaking • The cost to build the turbine • How often their wind turbine would need to be maintained/fixed For the complete activity and www.classroomengineers.org Page 3 of 8 media resources, please visit: Level Elementary Grades K-4 + WIND TURBINE DESIGN AND TESTING SUPPORT MATERIALS—FOR THE CLASSROOM VISITOR Background Information Air currents on Earth naturally generate wind. The wind’s power can be felt pushing against the human body just by standing outside on a very windy day. Since the first century a.d. or earlier, humans have invented machines to harness that wind power. Many of the early devices were designed to mill grain and so the name windmill was often used. Modern devices harness wind to produce electricity and are called wind turbines.