Generate Renewable Energy With Wind Turbines

Renewable energy sources are on the rise globally as we work to combat climate change and man-made pollution across our planet. Through this lesson, we look at how Wind Turbines generate electricity as students are challenged to create their own renewable energy sources!

Through the utilization of an engineering design process, students will brainstorm different wind turbine designs based upon the specifications and constraints of the challenge. Students will then apply prototyping techniques to design and build their very own wind turbine!

Once built, students will be able to test and evaluate the performance of their wind turbine as we continue to make connections to the real-world. We will also discuss the importance of redesign as we reflect upon the performance of our solutions and work to make improvements using what we’ve learned.

There are countless ways to adapt and modify this lesson to suit the needs of elementary, middle, or high school learners based upon prior experiences and abilities. There are also endless adaptations that can be based upon available resources, time, and focus of your course’s objectives.

Lesson Objective

• Students will be able to identify the differences between renewable and nonrenewable energy sources
• Students will be able to identify how electricity can be created
• Students will understand how wind turbines work
• Students will utilize an engineering design process to develop their own solutions to a real-world problem
• Students will utilize computer aided design (CAD) software to create a 3D model that can be produced on a 3D printer
• Students will understand how 3D printers work and how they are used in industrial settings
• Students will be able to safely apply prototyping techniques to construct designed solutions to real-world problems

Essential Questions

• How do we consider trade-offs when choosing a technology, product, or system?
• How can energy be created?
• How can we use technology to design a solution to a real-world problem?

Click here to view the full lesson plan here for alignment to standards, pacing, and additional details for lesson implementation and instruction

Materials

This is a list of materials each student will need to complete this lesson:

• Computer or tablet with Internet access
• Computer Aided Design (CAD) software
• 3D Printer and Filament
• DC Motor
• Voltmeter (or multimeter) per student or per group
• Paper, pencils

Additionally, the following resources can be utilized to aid in instruction and engagement:

• Click here for sample 3D models shown throughout this lesson
• Click here for the One Page Brief for student project planning
• Click here for a thumbnail sketches planning document to assist with the research stages
• Click here for a technical drawing planning document to assist with the design stages

Modifications

In addition to this lesson plan, see our One Page Brief that can be used to guide students through the lesson. These are additional examples as to how this lesson could be modified:

• Additional tools and materials to construct prototypes such as cardboard, popsicle sticks, styrofoam, or hot glue to combine with 3D printed parts
• LED bulbs can be attached to the motor as they will illuminate with generated electricity from turbine
• If DC motors used are 5v, a 5v USB adapter can be connected so the motors (generators) will charge mobile devices (if enough electricity can be produced based on performance of the turbine)
• Incorporating a microcontroller, like a Micro:Bit or Arduino, to interact with wind turbine prototypes could add elements for computer science

Assessments:

Opportunities for formative assessments will take place through observations and discussions between students as they interact with the content in this lesson. For summative assessment, we recommend utilizing a rubric to assess how a student was able to apply the engineering design process to solve an open-ended problem. Click here for our Example Assessment Rubric.

Where Does Electricity Come From?

In today’s world, we rely heavily on electricity. We need it for our homes, for our hospitals, to cook or to travel, even non-electronic things were made and delivered to us using electricity. But do we know what electricity is?

Electricity is phenomenon that exists in nature, but can also be created, stored, and used. This generated form of electricity is comprised of atoms that contain a positive or negative charge. These charged atoms are moving, or flowing, and we use this energy to power all of our electronic devices!

To create electricity for our homes, we have used power plants. A power plant typically uses fuels like coal or natural gas (fossil Fuels), or nuclear energy to create heat. This heat is then used to boil water to make steam. Through a series of pipes, steam is directed to a turbine or fan which is connected to a generator. Generators use magnetism to create electricity which is then sent to your homes through our power grids.

Power plants like these are considered to be nonrenewable energy sources because the fuel cannot be reused after being converted into heat to create steam. This process of burning fuel also creates a byproduct of harmful greenhouse gases that pollute our ecosystems.

Teacher Notes: Adapt key phrases, concepts, and terms to best fit your students’ needs. Allow students to offer ideas as to how we interact with electricity. Additionally, utilize graphics and videos as visual aids when introducing how electricity and power plants work. Demonstrations with static electricity or magnetism may also assist in instruction and engaging your students’ interests.

What is Renewable Energy?

Now that we’ve learned how typically power plants burn fossil fuels like coal or natural gas to create heat, lets discuss a cleaner way to make electricity! Renewable energy are methods of creating electricity with fuel, or energy that can be reused. Renewable resources include natural energy forms like wind, water, or solar, as well as geothermal, biofuels, or even biomass waste. Unlike nonrenewable energy, renewable energy does not directly create greenhouse gas pollutants and use methods that will not run out.

There are different methods to creating renewable energy, but many of them use generators just like a typical power plant. Hydroelectric power plants use flowing water to turn the turbines of a generator and while wind turbines use wind. Some methods like geothermal or solar thermal use heat to create steam which turns a turbine, while photovoltaic cells, or solar panels, use sunlight to create electricity through flowing electrons.

But with of the different forms of renewable energy available, and with the clear benefits for the environment, why does renewable energy account for less that 15% of electricity created in the United States (in 2018)? Open discussion about the benefits and drawbacks of renewable energy.

Teacher Notes: Adapt key phrases, concepts, and terms to best fit your students’ needs. Key thoughts are that while renewable energy sources have many benefits, there are also drawbacks as with any technology. Identify the variety of renewable energy, how they are similar and different to nonrenewable sources, and why renewable sources are still vastly a majority in providing electricity to the US, compare globally.

Identify the Problem

As wind Turbines account for approximately 24% of the renewable energy created In the United States (which is only about 11% of total energy produced), they are one of the most widely used forms of renewable energy worldwide. While there are many benefits to wind energy, there are also many challenges. The first of which is cost, wind turbines are expensive and as they only create electricity when there’s wind, many companies can’t afford to produce wind turbines that may only be used part of the time. Wind turbines are also often considered to be ugly, loud, and can impact local wild life negatively.

Using an engineering design process, can we design and create our own prototype wind turbines that combat the drawbacks of typical wind turbines such as cost, looks, noise, and or wildlife impact?

Challenge Constraints include but are not limited to:

• You must address at least one of the defined drawbacks for wind turbines
• You have 1 day to brainstorm, 3 days to build, and 1 day to test & evaluate
• You must design your prototype to support the provided DC motor that will act as your generator
• Your 3D Model build volume may not exceed 36 in3
• You must incorporate at least three different materials

Teacher Notes: The main idea is that there are different forms of wind turbines which all may be more widely used if there were fewer drawbacks to wind energy (cost, looks, noise, wildlife impact). Discuss the concept of prototyping and how we will be using an engineering design process to attempt to solve this problem.

Why Solutions and Not Solution

The second step of our Engineering Design Process is “Brainstorm Possible Solutions.” A key part of this step is solutions being plural, meaning more than one. Why do designers and engineers think of more than one way to solve a problem?

Teacher Notes: Adapt key phrases, concepts, and terms to best fit your students’ needs. Main idea is there is NEVER any one solution to a problem. If possible, provide an example that relates to your students’ lives, like all of their different shoes, or phones, or video game consoles. Emphasize the importance of variety and why we must, as designers, think of as many ideas as possible.

Brainstorming Our Solutions

As we work to think of different ways to solve this problem, there are a few things we can consider to assist in our design. The first is learning from existing wind turbine styles. Wind turbines can have either a vertical axis (VAWT) or horizontal axis (HAWT) with different blade configurations for each. Take time to research and learn about the benefits and drawbacks to each type. Which do you think would best suit our needs and why? Remember, we must address at least one of the defined drawbacks for wind turbines in our designed solutions. The drawbacks are: Cost, Aesthetics, Noise, and Negative Impacts on Wildlife

After researching the various types of turbines, blades, and drawbacks, begin to brainstorm different ways you could construct your own turbine under the specifications and constraints of the challenge. Thumbnail sketches are a great way to think of many ideas quickly without getting caught up on the details. Once you’ve completed the thumbnail sketches, narrow your choices down as you create your final design.

For your final sketch, create a clear design that is neat and labeled. Consider drawing your design from multiple views (front, top, side, or isometric) to better portray your ideas. Utilize the lesson's one page planning brief to collect your ideas and develop your design.

Teacher Notes: Emphasize coming up with as many ideas as possible as students will tend to want to go with their first idea. Also reiterate the constraints and ensure students are factoring them into their designed solution. The detail in technical drawings can be modified based on age and prior skill of students.

Developing Our 3D Models

Now that we’ve brainstormed our wind turbine designs, it is time to begin to fabricate them! But before we can 3D print our parts, we need a 3D design. To create this, we will use computer aided design software, or CAD. There’s plenty of great free CAD programs out there, we recommend Tinkercad, FreeCAD, Fusion360, or OnShape for students.

When designing your model, there’s a few things to consider that will best prepare it for 3D printing:

• Size - Make sure you are keep track of your dimensions, or measurements as you design
• Base - Try to design a model with a flat base so it is supported while printing from bottom up
• Overhangs - When possible, avoid overhangs to reduce the amount of support material needed
• Tolerances - Where parts fit together or fit with something else, leave some “wiggle” room or a tolerance as the plastic will shrink during printing.

Teacher Notes: Students may better understand the purpose of CAD after being initially introduced to rapid prototyping production machinery. For beginners, experimentation is key when learning the basics of CAD software. Encourage patience and offer tutorials or techniques to support learners. Working with a USB mouse often makes CAD easier to use.

Utilizing 3D Printers

One of the key prototyping machines used by today’s professional designers, engineers, and scientists is a 3D printer. There are a lot of different types of 3D printers out there, but all 3D printers create physical objects you can touch and hold based on a 3D design or digital model. Some 3D printers melt rolls of plastic into the model, while others use light to harden a liquid resin. There are even 3D printers that can print concrete, metal, or living cell tissue!

Once students have completed their designs, it’s time to download and prepare them using Cura. Cura is not a CAD program in that it allows you to design your models. Instead, Cura “slices” models layer by layer to create a program file, or Gcode file, for the 3D printer to read. This Gcode file is a set of directions that the 3D printer follows as it prints your model.

In general, we recommend PLA filament for most classroom uses as it’s a safe plastic to print in schools and prints easily in nearly any setting. PLA works well for most applications, but if you need your prototype to be exceptionally strong, or able to resist the sun or high temperatures, consider looking into other materials that may better suit your needs.

When printing your student’s models, a “high speed” setting will probably be best to get all the models printed quickly at good quality. The default layer height for high speed is 0.38mm. If the models are small, detailed, or delicate, consider using a “standard” or “high detail” print setting which uses a smaller layer height. The smaller the layer height, the slower the print but the smoother and more refined the finished model will be. If you students have any overhangs, you should use support material. Support material is automatically drawn by Cura and it fills any gaps or structural flaws. After the model is printed, support material can be carefully removed by peeling it off of the model. When possible, avoid needing supports in your model design as it adds time, uses additional material, and may reduce the quality of the finished print. However, sometimes support material is unavoidable and needed to print designs.

Discussing Gcode is a good lesson in itself! Gcode is a list of directions for the machines to follow and can be read using a basic text program. Did you know early CNC machines required people to write Gcode manually? Luckily we have Cura for that now!

Teacher Notes: Depending on your student age group and classroom resources, the teacher may need to slice the models for the students. Ensure proper settings are chosen for selected filament and model quality. Reference LulzBot guides and tutorials for assistance in choosing filament and using Cura with your LulzBot 3D Printer.

Constructing Our Prototypes

In the final part of this stage in the engineering design process, we must construct our prototypes after all parts have been 3D printed. Depending on available resources and the specifications and constraints of the challenge, this step may involve assembling 3D printed parts together, or gluing other materials like popsicle sticks or skewers to parts that have been 3D printed.

Time will vary based on how many materials and resources students have to build with.

Ensure turbine blades have been securely fastened to the DC motors. Avoid using hot glue, as glue around the motor shaft could prevent the motor from spinning. A hot air gun or blow dryer allows PLA to be softened which may help in installation if some tolerances are a little tight.

Remember, proper safety procedures should be introduced to students when working in any maker space or lab environment. When students are around machines such as 3D printers, or using tools to cut or glue materials, students must be informed of potential hazards and taught how to use these resources safely. For reference, see the safety resources in the full lesson plan.

Teacher Notes: Safety is key. Ensure all students have been trained to use any available tools or resources and organize your room to ensure these resources can be monitored accordingly.

Testing Criteria

Before we test our solutions, we need to determine how we can test and evaluate them! First, we need a source of wind. Large circular fans or box fans work well for creating wind in a classroom, but remember lab safety procedures when testing your solutions! In addition to observing how our turbines turn in the wind, we can also measure how much electricity is being creating using a voltmeter or multimeter set to DC Volts. Connect the leads of your voltmeter to the wires of your turbine to monitor its output as you test!

If your turbine struggles to turn, don’t give up yet! Can something be added or modified to make it perform better? Consider adding cardboard or notecards to the blades to increase their surface area. Or elevate the base to make the turbine taller and catch more wind. No design is perfect, something we will discuss further in the next step!

Test each turbine for 2-3 minutes, moving the turbine around to find the best possible angle and air flow. Record the amount of volts measured during testing. Also make notes of any changes or modifications you made, as well as where your turbine best performed.

In addition to using a voltmeter to measure voltage, LED lights can be connected to the DC motors to show generated electricity by illuminating. Additionally, larger 5V motors may generate enough electricity to charge a phone using a 5v USB adapter.

Teacher Notes: Safety is key during any testing and experimenting stages of the engineering design process. Ensure a safe lab environment is created and no students are at risk during testing procedures. Have spare materials like notecards, tape, and cardboard ready for students to add to turbines that perform poorly. Remind students that these are PROTOTYPES, not finished models and that failure or room for improvement is expected and good when designing solutions to real-world problems.

Evaluating Criteria

In addition to testing the performance of our wind turbines, we also must evaluate how well they addressed the defined drawbacks of real wind turbines. Remember, your turbine prototype must address at least one of the defined drawbacks. These drawbacks are; cost, looks, noise, and negative wildlife impact.

Analyze your wind turbine prototype. Compare your design to the real wind turbines you research in an earlier step. How do you think your wind turbine compares to existing solutions? Do you think it would work well? Why or why not? Record your findings for a later step.

Teacher Notes: Create connections between the constructed prototype solutions and wind turbines out in the real-world. Encourage students to think critically as to how their turbines compare to professional designs. See the full lesson plan for additional modifications and considerations as to how to engage your students in this learning experience.

Redesign

No design is perfect, nor is it ever truly finished. As new technology is developed improvements like cost, speed, performance, or aesthetics can always be made. Consider your findings from testing and evaluating your wind turbine solutions. What worked well? What could be improved?

Create a sketch of an improved wind turbine design with changes you would make to allow your wind turbine to perform better, or better meet the evaluation criteria and solve our real-world problem. Your sketch should be neat, and label the changes you are making to improve your turbine’s performance. Include why you’ve chosen these changes and how you think they will improve your turbine. Utilize the one page brief document to assist in collecting your thoughts and reflection during this step.

Teacher Notes: Stress the importance of failure in design and engineering. No one enjoys failing, or not doing well, but the redesign step is a chance to reflect on both the good and bad of our designed solutions. Additionally, we can use observations made from other solutions as we create a proposed redesign with everything we’ve learned. Drawn and written redesign activities both work well with varying learning styles, we recommend a combination of the two. If time permits, students may use CAD to make a 3D model of their redesigned solution.

Collaborate and Share What We Learned

Create a presentation to share with your classmates that includes the following information:

• Name of your Turbine and what type of turbine it is
• Initial ideas from your brainstorming stage and why you chose the final idea you constructed
• Any key features or design characteristics
• Which defined drawback does your turbine address and how?
• How did your turbine perform during testing? What worked well and what could be improved?
• What changes would you make to your turbine if you were to complete this project again?

Where possible, included sketches and visuals to share your ideas with your classmates during your presentation. Record and share feedback to your classmates on their designs as you discuss similarities and differences between your designed prototype solutions.

Teacher Notes: Presenting and collaborating on what we’ve learned is important for students. Encourage the use of sketches, models, and visual representations from earlier steps to aid in students sharing their designs and results of their wind turbines.