Photovoltaic Cells and Renewable Power for Middle School

Photovoltaic Cells and Renewable Power for Middle School Math Students Lars Hondorf, Jefferson Middle School, Oak Ridge, TN Investigating Photovoltaic Cells A lesson and activity exploring the voltage and current produced by photovoltaic cells to engage middle school math students with PV cells and power generation. OBJECTIVES 7 th Grade Math, Algebra 1 • • Students will explore the relationship between photovoltaic cells and the voltage or current generated. Students will solve real-world problems involving the four operations using measured voltages and currents from photovoltaic cells. Students will analyze proportional relationships between the number of PV cells and generated voltage and currents, using them to solve real-world charging situations. Students will build a linear function that models a relationship between the number of PV cells and the voltage or current supplied. OVERVIEW Students will explore photovoltaic cells, examining the voltage and current generated from single and multiple cells. Students will be introduced to the PV cells, wires, light bulbs and socket and multimeter being used. They will create a circuit with a single PV cell. Students will be challenged to create and measure the most voltage and current using multiple PV cells. Throughout the lesson, vocabulary will be introduced as it is needed/used to allow for clear communication about PV cells, circuits, voltage and current. Students will be asked if it is possible to create a circuit that provides the voltage and current needed to charge a cell phone. MATERIALS • • • Multimeter with leads Photovoltaic Cells (2 or more per group) E 10 mini bulb mounts E 10 filament bulb, low voltage Wires with alligator clips Light source (as needed). PROCEDURES 1. Students carefully examine each component supplied, discussing names and usage within their group. 2. Student led discussion to build correct knowledge and vocabulary of materials. 3. Correct settings of multimeter displayed and explained. 4. Students explore methods of using the multimeter to measure voltage and current using only one PV cell, 2 wires, bulb and socket (light source if needed). 5. Student led demonstrations of measuring voltage and current after exploration. ENGINEERING CONNECTIONS While working in groups, the students will build and test circuits for voltage and current. They will then apply this information as they build and test additional circuits trying to maximize voltage and/or current. This will be followed by a presentation of the results. Utilizing what they have learned, students will discuss whether it is possible to use PV cells to charge a phone. LESSON OUTCOMES Students will be able to explain how to use a multimeter to measure voltage and current in a circuit, how using multiple PV cells in parallel or series in a circuit affects the voltage and current generated. They will discuss how multiple PV cells can be used to charge cell phones. 6. Challenge students to measure as much voltage/current as possible using only the provided supplies. 7. Student led demonstrations to show most voltage and most current generated. 8. During student discussions about the circuits with most voltage or current, support with additional vocabulary as needed. 9. Students will develop relationships (linear functions) between the number of PV cells used and the voltage or current measured. 10. Utilizing their relationships to support their answers, students will discuss whether PV cells can be used to charge a phone. REFERENCES “Solar Panel Series and Parallel Wiring. ” PVEducation. com, pveducation. com/solar-concepts/series-and-parallel-wiring/. Stearns, Philip. “Solar Charger Tutorial–Part 1. ” Voltaic Solar Blog, 21 Feb 2018, www. voltaicsystems. com/blog/solar-charger-tutorial-part-1/. “Teach. Engineering. ” Teach. Engineering, www. teachengineering. org/k 12 engineering/designprocess.