Activity 1: Renewable and Nonrenewable Energy Sources

1. Organize the class into small groups. Provide each group with a set of Energy Cards. Instruct the groups to read the definitions of renewable and nonrenewable energy and the information on each energy source card. They should determine if the energy source is renewable or nonrenewable and place each card under the correct term.
2. To check and see if their energy sources were correctly sorted, show the students the Differences between Renewable and Nonrenewable Resources video. Allow time for the students to sort their cards again if necessary.
3. As a class, discuss the advantages of renewable energy: 
   • Renewable energy can protect the environment by helping to reduce pollution and global warming.
   • Renewable energy can decrease our dependency on other countries for imported fuels.  
   • Renewable energy can create new jobs.
   • Renewable energy is a reliable source of power.
4. View the Renewable Energy 101 video to discover more about the advantages and challenges of renewable energy.

Activity 2: Harnessing the Power of Wind

1. Read The Boy Who Harnessed the Wind (Picture Book Edition) by William Kamkwamba and Bryan Mealer. Use the following questions to discuss the story:
   • What were some of the challenges Malawi faced?
   • How can weather impact crops?
   • How did Malawi's curiosity help him?
   • How did Malawi harness the power of the wind?
   • Why did Malawi want to harness the wind?
   • What would your life be like with no electricity? 
2. Project the Engineering Design Process Graphic onto a large screen and discuss the elements with the students:
   • Ask to identify the need and constraints. Engineers ask critical questions about what they want to create: What is the problem? What do we want to design? Who is it for? What do we want to accomplish? What are the project requirements and limitations? What is our goal?
   • Research the problem. This includes talking to people from many different backgrounds and specialties to assist with researching what products or solutions already exist, or what technologies might be adaptable to your needs.
   • Imagine possible solutions. Work with a team to brainstorm ideas and develop as many solutions as possible. Encourage wild ideas and defer judgement. Stay focused on the topic, and have one conversation at a time. Good design is all about teamwork.
   • Plan by selecting a solution. Revisit the needs, constraints, and research from the earlier steps, compare your best ideas, select one solution, and make a plan to move forward.
   • Create a prototype. Building a prototype makes your ideas real. Early versions of the design solution help your team verify whether the design meets the original challenge objectives. Push yourself for creativity, imagination, and excellence in design.
   • Test the prototype. Does it work? Does it solve the need? Communicate the results and get feedback. Analyze and talk about what works, what doesn't, and what could be improved.
   • Improve and redesign. Discuss how you could improve your solution. Make revisions. Iterate your design, continuously improving it, to make your product the best it can be within your design constraints.¹
3. View the Wind Power 101 video.
4. Organize the students into small groups and challenge each group to design and build a wind turbine that will generate electricity for either a poultry, dairy, pig, horse, or sheep barn. (See the Let's Raise a Barn lesson to learn more about different types of barns.)
5. Provide each group with a Wind Turbine Diagram. Lead a discussion about how a wind turbine works:
   • The rotor blades catch the wind and spin.
   • The generator converts the kinetic energy of the wind into electricity.
   • The power cable carries the electricity down the tower to the transformer.
   • The transformer increases the voltage.
   • The switchyard delivers the electricity to consumers.
6. Explain to the groups that they will need to construct a barn, using paper or cardboard, and create a wind turbine that produces electricity for the barn (lights up an LED light) using the materials provided. The wind turbine will need to include:
   • A rotor with blades spun by wind from a fan
   • A motor
   • Positive and negative wires
   • A tower
   The barn will need to include:
   • Four walls
   • A roof
   • At least one window through which an LED light powered by the wind turbine can be seen
7. Provide each group with a mini DC electric (hobby) motor, 1 positive wire, 1 negative wire, an LED light, and access to materials such as paper, cardboard, paper towel rolls, paper cups, plastic cups, 2-liter soda bottles, Legos, wood dowels, popsicle/craft sticks, corks, paper plates, wood skewers, push pins, paper clips, toothpicks, tape, etc. Keep handy a drill with a drill bit that matches the size of the motor shaft and a hot glue gun for adult use.
8. Allow time for students to design, build, test, and improve their wind turbines. (The following wind turbine designs are useful for teacher reference: Build a Simple Wind Generator; Designing a Wind Turbine; Working Model of Wind Turbine to Generate Electricity; Wind Turbine Design and Testing Tutorial)
9. Have each group present their wind turbine to the class.
10. Discover more about how farmers use renewable energy by reading My Family's Wind Farm, a story about a family in Iowa who produces corn, soybeans, and electricity.

Activity 3: Running on Sunshine

1. Show the students the School Crossing Sign image. Ask, "How does the sign get power to light up?" (The sign is powered by solar energy—sunlight.)
2. Read Running on Sunshine: How Does Solar Energy Work? by Carolyn Cinami DeCristofano. Use the following questions to discuss the story:
   • Where does electricity usually come from? (Power stations. Electricity is generated from steam.)
   • What problems can power stations create? (The smoke from the fires used in power stations can create unhealthy air and changes in weather patterns.)
   • What do solar panels do? (They catch energy from the sun.)
   • Do solar panels always produce electricity? (No, they do not produce electricity when the sun is not shining, like at night or during a storm.)
   • Who are the people working on ways to store solar energy for times when the sun is not shining? (Engineers) 
3. Watch the What is Solar Power? video.
4. Have the students rejoin their groups from Activity 2 and challenge each group to add a solar panel to their barn that will generate electricity to power a fan.
5. Provide each group with a Solar Panel Diagram. Lead a discussion about how solar panels work.
   • Sunlight hits the solar panel and generates an electric current (DC).
   • The electric current flows to the inverter, which converts DC electricity to AC, the most commonly used form of electricity.
   • The AC electricity flows from the inverter to the electrical panel, which directs the current to any appliance in the building that is using electricity.
   • When the solar energy system produces more electricity than is needed, electricity flows through a utility meter to the grid. The utility meter records the amount of electricity that is sent from the solar energy system to the grid.
   • When the solar energy system produces less electricity than is needed, electricity flows from the grid, through the utility meter, to the electrical panel, which directs the current to any appliance in the building that is using electricity. The utility meter also records the amount of electricity that is sent to the building from the grid.
6. Provide each group with a solar panel, 2 test leads, a mini DC electric (hobby) motor, and a fan blade.
7. Allow time for the students to build and test their solar panels outside with sunlight.
8. Have each group present their barns with a working wind turbine and solar panel to the class.
9. Discover ways solar energy is used on farms by viewing the Solar-powered Well Pumps and/or Solar-powered Poultry Farm videos.

Activity 4: Biomass

1. Project the Biomass Image onto a large screen. Ask the students, "What do corn, algae, manure, and sugar cane have in common?" After listening to their responses, clarify that they can all produce energy like electricity and fuels.
2. Explain that an energy resource that comes from plant or animal materials is called biomass. One source of biomass energy is manure. View the Pig Poop Power video.
3. Have the students complete the Methane Digester activity sheet. Use the information from the video and activity sheet to discuss how a manure digester works: 
   • Manure from farm animals is collected and pumped into the digester.
   • Microorganisms break down the organic material and produce biogas and digestate.
   • The energy in the gas is converted to heat, electricity, and fuel for vehicles.
   • The digestate is used as animal bedding and fertilizer.
4. Use the following steps to create a small-scale model to demonstrate the science that is taking place in a methane digester:
   • Add 1 and 1/2 cups of warm water to an empty clear, plastic water bottle.
   • Add 3 tablespoons of yeast and 3 tablespoons of sugar.
   • Mix the water, yeast, and sugar together, and place a balloon over the end of the bottle.
   • As you perform each step, narrate the simulation. Manure from farm animals is flushed from the barn to covered lagoons (the water bottle). The manure is biomass (represented in the simulation with sugar). Anaerobic bacteria (represented by yeast) is mixed with the manure, resulting in a biogas that can be used to power generators and create renewable electricity.
   • Observe the changes that take place over the next 30-60 minutes.