Earth & Environmental Sciences, K-8
March 21, 2017
Have your students ever wondered why solar panels on a row of houses all face the same direction? If you approach the topic from the right angle with the right stuff you can easily create a hands-on investigation. That’s right, no waiting, waiting, waiting for the sun. The question really comes down to which angle will be most effective at collecting light and, therefore, power? You will just need a small flashlight fastened with a rubber band to a ruler to keep the distance from the sensor to the flashlight constant, and a protractor to vary the angle— and a Wireless Light Sensor.
Looking at the data, your students should see that the sensor was blinded by the light at 900. That’s correct, a right angle is indeed the right angle.
Ready to take the activity outdoors? Here comes the sun, so investigate the different ways the sensor— our model of a solar panel— can be positioned for optimal exposure. Sets of students could compare the light intensity of sunlight when different sensors are propped at different angles relative the sun.
Students will get different results depending on the time of day. In this case, the propped-up sensor was facing east during the morning hours. Based on the data, it was catching more rays than the sensor that was flat on the table.
Solar panels on houses in the northern hemisphere are typically positioned for southern exposure on the roofline. At this direction and angle, they get the most power over the course of the day and year. Another application of the relationship between light and angle occurs when studying objects in space. When making measurements of celestial bodies, astronomers will use telescopes that move with the object in space to this minimize the effect that a changing angle might have.
Now that your students have some basing understanding of why the angle is so important, you could take the opportunity to have them design their own experiments. They could determine the relationship between distance from sensor to the source, or explore the effectiveness of different materials at blocking light intensity. They could even set the Wireless Light Sensor into logging mode and analyze the patterns that emerge over days or weeks!
As your students gain in understanding of this and other core topic, you can rest assured that their future will be so bright, they’ll have to wear shades.