techdirections February 2013 : Page 18

Inspiring Educators to Teach Wind Energy By Gustavo Perez gperez@esc1.net T HE need to teach stu-dents about alternative energy will continue to gain importance given the increasing growth and demands of the renewable energy industry. This article describes an activity focused on wind energy that surements and investigations: O Measurement of wind speed. O Measurement of the effects of design on power output. O Measurement of optimal wind direction. O Measurement of wind speed over land or water. and quantify wind energy. Teams would conduct ﬁeld testing using their prototypes, research industry benchmark values for wind speed to gauge the performance of their design, and present their results and ﬁndings along with a short demon-stration to the other participants. Activity Launch I started my presen-tation to the educators at the symposium with an interactive video that posed a few frequently asked questions regarding wind energy. Scenes of rotating turbines in the backdrop built some background, piqued interest, and helped to initiate a conversation about wind energy. I presented partici-pants with a culminating event for the session. They were to construct a functional device to capture, harness, Driving Discussion After offering some friendly give-aways for correct responses to the video, I introduced driving questions to focus the activity. (See Fig. 1.) The questions provided a reason for the wind energy investigation and served as a “driver” for additional questions and inquiry. After reviewing the driv-ing questions, the participants gener-ated additional questions they would answer in the course of engaging in the activity. Next, I facilitated a “know” and “need to know” discussion and captured responses on a slide. (See Table 1.) The discussion helped to generate more ideas and things to consider. Fig. 1—Driving questions I introduced at the Annual STEM Symposium sponsored by Texas’s Region One Education Service Cen-ter that can be implemented by teachers in the STEM (science, tech-nology, engineering, and mathemat-ics) ﬁelds. I developed the activity speciﬁ-cally to introduce the concepts of harnessing wind energy, explor-ing wind energy as power, and the representation of wind energy using multiple forms—tabular, graphical, and numeric. The activity allows for working with the following mea-Gustavo Perez is a STEM specialist, STEM Center of South Texas, Edinburg, TX. Table 1—Know and Need to Know Know O Need to Know O Create something that will spin fast with little resistance Paper, scissors, Lego pieces, rulers Wind resistance Gain freedom from other power industries/countries Kinetic energy transforms to other energy What other materials can we use? What direction will the fan face? What speed setting will the fan have? What does the best team get? How are we going to be graded? What are the length and require-ments for the presentation? O O O O O O O O O 18 tech directions X FEBRUARY 2013

Inspiring Educators to Teach Wind Energy

Gustavo Perez

THE need to teach students about alternative energy will continue to gain importance given the increasing growth and demands of the renewable energy industry. This article describes an activity focused on wind energy that I introduced at the Annual STEM Symposium sponsored by Texas’s Region One Education Service Center that can be implemented by teachers in the STEM (science, technology, engineering, and mathematics) fields. I developed the activity specifically to introduce the concepts of harnessing wind energy, exploring wind energy as power, and the representation of wind energy using multiple forms—tabular, graphical, and numeric. The activity allows for working with the following measurements and investigations: • Measurement of wind speed. • Measurement of the effects of design on power output. • Measurement of optimal wind direction. • Measurement of wind speed over land or water. Activity Launch I started my presentation to the educators at the symposium with an interactive video that posed a few frequently asked questions regarding wind energy. Scenes of rotating turbines in the backdrop built some background, piqued interest, and helped to initiate a conversation about wind energy. I presented participants with a culminating event for the session. They were to construct a functional device to capture, harness, and quantify wind energy. Teams would conduct field testing using their prototypes, research industry benchmark values for wind speed to gauge the performance of their design, and present their results and findings along with a short demonstration to the other participants. Driving Discussion After offering some friendly giveaways for correct responses to the video, I introduced driving questions to focus the activity. (See Fig. 1.) The questions provided a reason for the wind energy investigation and served as a “driver” for additional questions and inquiry. After reviewing the driving questions, the participants generated additional questions they would answer in the course of engaging in the activity. Next, I facilitated a “know” and “need to know” discussion and captured responses on a slide. (See Table 1.) The discussion helped to generate more ideas and things to consider. Whole Group Mini-Lesson I presented a few slides from various sources to further establish a real-world “need to know” and “buyin” regarding wind energy and the activity requirements. Content of the slides included: • A graph showing total world energy capacity. • A graph of usage in the U.S. vs. other parts of the world. • A map showing annual average wind power throughout the U.S. • A power equation used to quantify wind energy. • A chart of wind speed vs. power. • A sample calculation of wind energy using wind velocity. • A summary of the drivers for increased use of wind energy. Design Goals I presented the design goals and expectations through a rubric. The criteria selected served as a guide for materials, measurement, design, and calculations. I included novice, intermediate, and outstanding levels of performance to help with assessment and directing the progression of activities. (See Table 2.) Team Building Teams engaged in a simple challenge titled “Nothing But Air,” in which team members created meaningful phrases from color-coded word banks. (See Fig. 2.) Each member was assigned a specific word bank and the objective was to create as many meaningful phrases as possible in two minutes. (See Fig. 3 for sample results.) This activity got people talking to each other and by the time it ended, the room was full of laughter and friendly interaction. I asked for examples of participants’ phrases and joined in friendly critiques. In summarizing the activity, we discussed the creation of similar activities that teachers could use with their students. The discussion included limited English proficiency (LEP) standards, English as a second language (ESL) standards, and other concerns involving access to academic vocabulary. Materials Teams were given a list of the materials available for design and testing: • Cardstock • Hole punch • Scissors • LEGO pieces (to serve as beams and connectors) • 1 NXT brick (robot brain) • 2 LED power cables • 2 NXT bulbs (green and red) • 2 NXT LED lights • 1 NXT sensor cable • 1 NXT vernier adaptor • 1 vernier flow-rate sensor • 1/4" piece of rubber Testing Apparatus We built a testing apparatus, step by step (see Photo 1), and I modeled how to run a simple program to capture real-time data using NXT data-logging software. (See Photo 2.) Requirements/Limitations Returning to the rubric, a few design requirements and limitations were highlighted. They included: • Use of a minimum of 30 LEGO pieces. • Size: as large as mechanically feasible. • Time limit: two hours. • The blade can be positioned in any direction, angle, or distance from the wind source. • Only the wind can move the blades during testing. Brainstorming, Design, Construction At this point, the participants needed a few minutes of processing time. I encouraged them to start sketching their ideas to conceptualize a design. After completing their initial drawings, the teams shared their ideas with each other. Each team provided justifications for their approaches, which served as catalysts for deeper conversations around the content and goals of the activity. Teams proceeded to design, draw, and cut their wind blade patterns from the cardstock. They punched holes in the blades and inserted LEGO connectors through the holes. The connectors were then attached to LEGO beams to function as a skeleton and support structure for the wind blades. (See Photos 3 and 4.) Testing Participants removed the water propeller from a flow-rate sensor and fitted their blades onto the shaft of the sensor using a small piece of rubber (see Photo 5) and conducted initial tests. (See Photo 6.) Needless to say, some designs performed better than others. We then discussed such variables involved in performance as area, form, and position. After preliminary test runs, participants collected wind speed data. I introduced a power equation for quantifying power generated: P = ½ (air density) (area swept by rotor) (wind speed3) Teams soon realized they needed to research the air density at sea level and make some numeric conversions in order to use the formula provided. They learned that the air density at sea level is 1.22 (kg/ m3). They proceeded to research and convert the recommended industry benchmark wind speed of 14–16 km/hr. to 9–10 miles/hr. to 4–4.5 m/s. This conversion was needed to compare the wind speed data collected with the flow-rate sensor rated at 0–4 m/s for liquid flow. As a result, only approximate speeds would be generated for air flow. Modifications followed as teams attempted to make refinements to increase performance. To this point, teams had conducted tests indoors, but seeing strong winds outside—evidenced by palm trees swaying back and forth—they wanted to test their designs outdoors. The current data collection setup required use of a laptop, but with some minor modifications, a program could be set up to collect wind velocity and display it as a meter. I offered a five-minute mini-lesson to make these modifications (see Photo 7) to a member from each team (the programmer) and directed them to work with their group members. Tests were then conducted outdoors. (See Photo 8.) The session concluded with a brief discussion of what worked, what needed improvement, and plans for implementation for the various designs. Using Post-It notes, participants submitted entries of the STEM relevance of the activity. (See Table 3.)

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