Lesson 2 – Exploring Solar as an option for electricity
Grades 7 (6-8/middle grades)
Earth ScienceSPI 0707.7.7 Analyze and evaluate the impact of man’s use of earth’s land, water, and atmospheric resources.
SPI 0707.Inq.1 Design a simple experimental procedure with an identified control and appropriate variables.
Engage: Hold up a solar panel and ask the kids what it is and what it does. Once it has been identified that it is a solar panel and that it uses sunlight to make things work as students to think of different things in their life that they know use solar panels. Ask students if they have seen solar panels around town or anywhere else. (I will have some pictures from around the area of things that use solar panels that the students may have seen at some point in time to help them out).
Ask students to explain how they think a solar panel works. Have students draw a solar panel or write what they believe happens when the sunlight hits the surface of the solar panel.
Ask students if the amount of light would influence the amount of voltage the panel would produce. Have students explain why they have that belief; what is the reason or basis for their thinking.
Inform students that they are going to be investigating the amount of voltage a single solar panel will produce under a variety of conditions. Remind them that it is very important to keep accurate data since they will be using this data to complete their assessment task for this lesson.
Explore:
Activity 1: Testing solar panels in variable conditions
Materials: 3 way lights, multimeters, solar panels, black construction paper, data logs, protractor.
1-Indoor: test solar panel to determine affects of different amounts of light (3-way lightbulb), different angles of panel to direct light as well as distance from direct light, and shadow(colored paper) on amount of volts produced.
2-Outdoor (weather permitting): amount of voltage produced outside in direct sunlight, situated at different angles, different locations around the campus (on the track, in the garden, parking lot) and in the shade. Each class period will gather data that will be shared in all classes to determine “peak hours”. This could potentially turn into a yearlong project with students gathering data throughout the year in different conditions, temperatures, seasons, etc.
3-parallel and series: Students will connect solar panels in parallel and in series to determine what affect this has on voltage.
Explain: Once students have gathered their data they will return to their table groups to complete the data analysis questions. The data analysis document will help students see the changes in voltage and current so they will be prepared to complete the final task for this lesson. I make sure to go over all the calculations and answer questions at this time to help students understand what is going on.
Evaluate: Miss Lawrence wants to run her Christmas lights in the classroom using solar power. For 1 strand of lights determine how many solar panels she would need to use, how they should be arranged (series or parallel), and the best location on campus that would allow her to have her lights on the majority of the day.
Math connection: Students can complete analysis of % increase along with making predictions for 4 and 5 solar panels in series and parallel. Students can graph their data and test their predictions in their science class.