Slide | Teaching Moves |
1 | Welcome students to the course. Introduce yourself, then invite students to introduce themselves before playing the icebreaker in the next slide. |
2 | Icebreaker: Two Truths and a Lie - Introduce the game to the group by explaining that this is a fun icebreaker activity to help them get to know each other better.
- Explain that the game is called Two Truths and One Lie and it involves each person in the group sharing three statements about themselves, two of which are true and one of which is false.
- Tell the group that the goal of the game is to guess which statement is the lie.
- Instruct the group on the game rules, which involve sharing three statements and having the others guess which one is a lie.
- Emphasize that one statement must include a previous experience working in groups.
- The person who guesses the most lies correctly wins.
How to make the groups? - For this game, it's best to divide the students into smaller groups of 4-5 people. This grouping can remain for the rest of the unit - i.e. students will complete their maker projects through this grouping.
- This ensures that everyone in the group has a chance to share their statements and that everyone in the group has a chance to guess which statement is the lie.
- If there are an odd number of students, the teacher can participate in one of the groups or assign a student to be a "floater" who moves between groups to even out the numbers.
What should I do in case I have a large number of students? - If the teacher has a large number of students and it's not feasible to have everyone play in small groups, there are a few options.
- Option 1: Split the class into smaller groups and have each group play the game simultaneously in different parts of the room. The teacher can circulate around the room to answer questions and ensure that everyone is participating.
- Option 2: Have students play the game in pairs instead of in small groups. Each student can take turns sharing their statements and guessing which statement is the lie. The teacher can circulate around the room to answer questions and ensure that everyone is participating.
- Option 3: Have students play the game as a whole class. The teacher can call on students one at a time to share their statements, and the whole class can work together to guess which statement is the lie. This option may take longer, but it allows everyone to participate in the game.
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3-4 | Introduce students to the unit, in particular the theme of “Solar Power” Invite students to key in their response to the question, “What is one word that comes to your mind when you think of the word ‘Solar’?” Teachers should set this up to display as a wordcloud using browser-based software like Mentimeter. |
5-7 | These slides are optional slides to provide more background on solar power. Slide 7 - Archimedes’ Death Ray - If time permits, teachers might show a snippet from this Mythbusters episode which attempts to recreate Archimedes’ “death ray”. Spoiler alert - they fail spectacularly!
- Archimedes' "death ray" is just one example of ancient attempts to harness the energy of the sun.
- There were other ancient civilizations that attempted to harness solar energy, such as the Egyptians who constructed simple solar cells near the Great Pyramids, and the Greeks who built sunrooms to capture the sun's warmth.
- Students can be encouraged to consider how these early attempts to harness solar energy paved the way for modern solar technology.
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8 | Share that solar power has been gradually growing in terms of the share of total energy production in the US over the years. Ask students about their observations of the graph. Possible observations below: - Solar power has increased over the last few years
- Solar power is projected to increase over the next few years (students may also question how these projections were made - if so, teachers can point towards additional federal/state/private investment in solar power; see resources)
- Total energy production is projected to increase over the next few years
- Electricity generated from solar sources is projected to increase as a proportion of total electricity generation over the next few decades (~5% today, to 20% by 2050).
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9 | Solar power has untapped potential to generate electricity that the US needs. Play the video, and ask students to consider the following: - What is the main message of the video? Do you agree with it?
- A: Main message: we should double down on solar energy, it has great potential to meet our energy needs
- A: Accept multiple answers to the second question - they might agree with the message of the video, or they might be skeptical. Teacher may wish to probe to find out more about their thinking on both counts.
- What other considerations do you think we should consider when calculating the potential of solar power?
- A: Accept a variety of answers to the second question, e.g. transmission of solar power from point of generation to point of use, storage costs of solar power, global warming…
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10 | At the same time, we’re struggling to properly exploit the potential of solar. Play he video, and ask students to consider the following: - Given the enormous potential of solar power, why do you think Tesla is still struggling to deploy it around the US?
- A: They have struggled to find a cost-effective solution that is sufficient durable and can be used for a long time
- Now, how would you describe solar power in one word? Is it the same word you chose at the start of the lesson?
- A: Accept a variety of answers. For students who change their minds, probe to find out more about their thinking
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11-12 | Run through the unit overview and objectives of the lesson. Highlight the Big Question and share that we will revisit it at each project. |
13 | Ask if students are familiar with the EDP and play the video. Share that each project will flow according to the Engineering Design Process (EDP). Highlight that the EDP is how engineers in the real world design solutions to pressing problems, and we will be using a similar process throughout the unit. |
14 | Clarify that this is the version of the EDP we will be using. Despite superficial differences between this version and that from the video in the previous slide, the fundamental principles are the same. |
15-17 | Ask if students have tried to start a fire while camping - discuss their experiences and challenges doing so. Tell students, “Now, we will see the challenges and dangers faced by a group of people in Africa when trying to build cooking fires.” - Play the video summarizing the challenges faced by the region.
- Based on the video, ask students to verbally share the energy and deforestation challenges faced by residents, and the negative impacts these challenges have on the local community.
- Note: The video shows an ‘outsider’ from the UK proposing to use solar ovens to address the energy challenges faced by the Botswana people. Some students may find this ‘white savior’ approach problematic. If appropriate, teachers can facilitate a discussion on the sensitivities behind proposing and implementing solutions to developing world challenges.
Distribute the Design Brief. Introduce the challenge of designing and implementing a sustainable cooking solution that can provide reliable and affordable access to clean energy for cooking in the Nyakach region. Discuss the importance of considering the cultural, economic, and environmental factors when designing and implementing sustainable solutions for energy access and deforestation challenges. |
18 | Introduce the concept of solar cookers and explain that they can provide a sustainable and safe alternative to traditional cooking methods. Ask learners: - How does this work? (Encourage them to consider the construction of the solar cooker, and how the marshmallows within are cooked.)
- What do you think are the materials needed to create a Solar Cooker? (Encourage them to study the solar cooker in the image closely, and think about the role that the different materials play in cooking food.)
- What should the solar cooker be able to do? Under what conditions should it be able to function? (Probe learners to think about the context of use - would it look different if it was used in sub-saharan Africa vs. in their backyard?)
The intent of the questions above are (i) to provoke excitement, and (ii) to get students to consider the design & function of solar cookers from first principles. |
19 | Discuss the design specifications: - Discuss the importance of cost-effectiveness in the design of the solar cooker, particularly for use in developing countries where resources may be limited.
- Emphasize the importance of passive solar energy in the operation of the cooker and why it is essential to have a solar cooker that doesn't rely on external power sources or fuel.
- Explain the optimal time of operation for a solar cooker and why it's crucial to have ample sunlight available during the cooking time.
- Discuss the safe cooking temperatures that the solar cooker should be able to reach and maintain and why it's important to consider this factor when designing a solar cooker.
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20-21 | Use the acronym D.A.R.E to guide the discussion of how a solar cooker functions. Explain each step of the acronym: - D: Discuss how the reflective surfaces direct sunlight onto the cooking area.
- A: Discuss how the black materials absorb all wavelengths of visible light and transform it into heat energy.
- R: Discuss how insulation, lids, and other methods are used to retain heat inside the cooking space and minimize heat loss.
- E: Discuss how solar cooking is a healthy and sustainable way to cook food and eat it using only the power of the sun.
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22 | Introduce the concept of radiation, convection and conduction, as well as the related concept of conductivity. - Heat can be transferred by three mechanisms: conduction, convection, and radiation.
- Convection is the transfer of heat through a fluid by the combined effects of conduction and fluid motion. Convection can occur in fluids such as gases and liquids. In the example, convection happens when the water in the pot is heated up. Heat is transferred from hotter parts of the liquid to colder parts.
- Radiation is the transfer of heat through electromagnetic waves, and is independent of any medium. Radiation can occur in a vacuum or in a gas, liquid, or solid. In the example, radiation happens when heat is transmitted from the electrical heating coil to anything you place near it. That’s why your hand feels hot when you place it close to a heating coil.
- Conduction is the transfer of heat through a material without any net motion of the material itself. Conduction occurs within a solid or between solids that are in contact with each other. In the example, conduction happens when heat is transferred from the handle of the pot, to the hand in contact with the handle.
- The thermal conductivity of a material is a measure of its ability to conduct heat. Does the pot handle have high or low thermal conductivity? (A: Low - it is a thermal insulator)
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23 | Explain the concepts of reflectivity and absorptivity as it applies to radiation. - Reflectivity: how effective a material is at reflecting radiation. Ask students if a mirror has high or low reflectivity (A: High).
- Absorptivity: how effective a material is at absorbing radiation. Ask students if a sweater has high or low absorptivity (A: High).
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24-25 | Explain that knowing what materials to use in the solar cooker requires an understanding of their properties. Selecting the right materials will enable the solar cooker to function optimally. Invite students to fill up Activity 1 in their worksheet. Sample answers are below. Property | Description | Example of material that has high levels of this property | Example of material that has low levels of this property | Absorptivity | How well a material absorbs radiation | Metals (copper, aluminum, zinc…) Black surfaces | Wool, cotton, newspaper | Conductivity | How well a material conducts heat | Metals | Insulators | Reflectivity | How well a material reflects radiation | Polished or shiny surfaces | Black surfaces | Get students to share their responses and address any misconceptions which occur. |
26-28 | Get students to form groups of 4-5 students each. Set up four stations, one for each component of the solar oven: - Reflector
- Absorber plate
- Cover
- Insulator
Students will circulate between each station, reading the information presented there and completing Activity 2 in their worksheet. Answers are presented below: Once students have completed the worksheet, provide the answers on the screen and invite groups to check against their own answers. Address any questions or misconceptions which come up. |
29 | Consolidate learning by sharing that using materials with the appropriate thermal properties is crucial to building an efficient solar oven. |
30 | Invite students to complete the exit ticket and hand the worksheet in for checking. |