We live in a world that is made possible by the energy around us. While we cannot always see or touch energy, energy is everywhere and its usage has become as vital to human life as food, water, and shelter. We depend on energy for essential services, such as to warm or cool our homes, to grow and cook our food, to purify and deliver freshwater, to provide transportation, and to enable us to communicate. All of them are essential to life as we know it. Energy is an important topic and scientists and researchers are still working on finding better solutions to meet the global demand for energy that is affordable, dependable, and won’t cause more harm than good.
This unit is designed to strengthen the teaching of the 4th grade Next Generation Science Standards (NGSS) related to the topic of energy by providing a close look at the science behind how a wind turbine can be used to generate electricity. It is inspired by the story of William Kamkwamba, a 15-year-old farmer from Malawi who built a windmill in his village to bring electricity and water during a time of famine.
Kamkwamba’s story rose to fame in 2006, when a local newspaper wrote about the boy who created a windmill to power his home and irrigate his family farm. He was featured in a 2007 TED talk, where he nervously told his story. This inspired several benefactors to sponsor his education at the African Bible College Christian Academy in Lilongwe, the capital of Malawi. He went on to receive a scholarship to the African Leadership Academy and in 2014 graduated from Dartmouth College in New Hampshire with a degree in Environmental Studies. He followed up with an additional TED talk in 2009, as well as wrote a memoir about his experiences entitled “The Boy Who Harnessed the Wind: Creating Currents of Electricity and Hope” that has been adapted into several easy-reader versions and biographies. It is also the basis of a 2019 Netflix film and several poignant documentaries, all of which I will reference in the teacher resources section. He was named one of Time Magazine’s 30 People Under 30 in 2013. He now works with the WiderNet Project in Chapel Hill, NC to develop technologies and curricula that help young people bridge the gap between ‘knowing and doing’ in Malawi, and across Africa. 1
Kamkwamba’s story is just one of the millions in the global quest for energy. On one side, it is a simple tale of a boy who built a windmill out of junkyard parts so he could listen to some music and light his home. I believe most students can connect to that idea no matter their age. Upon looking deeper, it also inspires some profound questions about humanity’s relationship with energy. Kakwamba’s ingenuity as he worked with local resources to meet a demand for energy during a time of famine will give learning about wind-turbine generated electricity a personal face and a global connection. I was inspired by his story, and I believe my students will be as well.
This curriculum unit is the result of my work in the 2019 Yale National Initiative seminar titled Energy Sciences. This two-week intensive, teacher-led summer institute was led by Dr. Gary Brudvig, Yale Professor of Chemistry and Molecular Biophysics & Biochemistry and director of the Yale Energy Sciences Institute. I have 18 years of experience as an elementary teacher at the time of this writing, and for the past five years, I have been developing STEM lab curricula and teaching STEM to K-4 grade students in New Haven, CT.
New Haven demographics reflect those of many urban areas, with more than 80% of the local student population receiving free or reduced-price lunch. In addition to meeting the full educational requirements of the Connecticut State Standards, our "Communications" themed magnet school includes specialized programs in public speaking and debate, Chinese and American Sign Language, and communication technologies such as photography, video production, and a robust K-4 robotics program. The STEM lab is a hub of discovery and learning and is where many of the technological elements of our magnet program come to life. It is also where much of the "hands-on" Next Generation Science Standards (NGSS) teaching takes place and where this unit will be taught to several classes of 4th-grade students.
As it turns out, energy is an incredibly huge and diverse topic. This unit will not help you teach everything there is to know about energy in the 4th grade NGSS standards. It will, however, serve as a supplement that will help students develop a deep understanding of the process of generating electricity
The timing of this unit should take 8 1 hour lessons, but these lessons lend themselves to be readily customizable in complexity and scope. The first three lessons are background information (learning what Kamkwamba learned) as well as introducing Kamkwamba’s story.
The end-product of this project is to design and construct a scale replica of Kamkwamba’s windmill from the ground up. They will create “electric wind" like Kamkwamba. His original windmill was about 14 feet high, and I built a 1:2 scale model as a demo piece (7 feet tall, photos and instructions included). Students will work together to create a scale model (1 to 3 feet tall) of a windmill. They will need to design the tower, the blades with a shaft and rotor, an electrical generator to power an LED or a buzzer, and a circuit to transmit power.
In a K-12 education based on the current Next Generation Science Standards (NGSS), students learn about energy from the sun starting in kindergarten. First graders learn about light and sound waves, while in third-grade students are learning more about forces and their interactions. It is not until fourth grade that students learn about how energy can be transferred from place to place by sound, light, heat, and electrical currents, as well as that energy and fuels are derived from natural resources that impact the environment. A typical ten-year-old fourth-grade student should also have some background knowledge based on their experiences. They usually know electricity travels from an outlet to a device, and that a switch can control the flow of electricity. They know fuels such as gasoline are a source of energy to make vehicles move. They know batteries store energy, come in different sizes, and that some batteries can be “recharged” (technically batteries are not recharged, they are re-energized). They may also have misconceptions about energy such as “batteries have electricity inside them”, or that “energy can be created”. It will be important to build on what students already know, as well as to challenge their thinking on misconceptions as they arise.
Tackling an engineering task of building a working windmill is going to take an understanding of several scientific ideas first, beginning with some background on the essential questions “What is energy?” and “How do we get the energy we need?” The following background information takes the topic of energy that is very large in scope and although it is general, it will be sufficient understanding to prepare an educator for teaching 4th graders about energy.
What Is Energy?
Perhaps the simplest answer is that energy is the ability to do work, and work is what makes things happen. Without energy, nothing would ever change. We can observe energy as it interacts in various ways, such as producing movement, heat, or light for example.2
We classify energy in two ways. First is potential energy, which is the amount of energy something has stored inside it. Anything can have potential energy. A battery has potential energy stored by a difference in ionic concentration. A book on a table has potential energy as well, how much depends on the mass of the book and its height. A great deal of energy is also stored in chemical bonds.
The second is classification is kinetic energy, which is the energy of an object in motion. Anything that is moving has kinetic energy. Mechanical objects, such as a clock, have kinetic energy, but so do light, sound, wind, and water.
Energy cannot be made or destroyed; it can only be changed into different forms. Those forms include:
Chemical energy: energy stored in the bonds of chemical compounds (atoms and molecules). Chemical energy is released in a chemical reaction, often in the form of heat. We use the chemical energy in fuels like wood and coal by burning them.
Electrical energy: the energy carried by moving electrons in an electric conductor. It is one of the most common and useful forms of energy. Other forms of energy are also converted to electrical energy. For example, power plants convert chemical energy stored in fuels like coal into electricity.
Mechanical energy: the energy a substance or system has because of its motion. Machines use mechanical energy to do work.
Thermal energy: the energy a substance or system has related to its temperature, i.e., the energy of moving or vibrating molecules. We use radiation to cook food.
Nuclear energy: the energy that is trapped inside each atom. Nuclear energy can be produced either by the fusion (combining atoms) or fission (splitting of atoms) process. The fission process is the widely-used method. Even mass is a form of energy, as Albert Einstein’s famous E = mc² showed.
We know energy is not lost because the law of conservation of energy, also known as the first law of thermodynamics, states that the energy of a closed system must remain constant—it can neither increase nor decrease without interference from outside. The universe itself is a closed system, so the total amount of energy in existence has always been the same. The forms that energy takes, however, are constantly changing. For instance, chemical energy is converted to thermal and light energy when a candle is lit. If one adds up all the forms of energy that are released in the combustion, in this case, both thermal and light, one will get the exact decrease of chemical energy in the fuel source.
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