This week, we had another experiment related to sustainability, energy, and technology, but it specifically focused on the solar energy. In order to make this lab we needed to use the appropriate materials such as a flashlight, a small solar panel, ruler, and some transparent color papers. This time the lab took us two classes because the experiment was divided into two measurements.
For the first half of the observation, the experiment investigates how changes in light intensity, (distance from the light source) affects the amount of current and voltage a solar cell can produce. My classmate and I were asked to put the light at various distances and then see how much light reached the panel. Later on, we recorded the voltages for each distance with the aid of the excel sheet. After collecting all the data needed, we made a graph to explore the measurements that we got. We concluded that the distance from the flashlight will affect the solar cell output. The intensity of light on the solar panel will decrease, due to its distance from the cell. This occurs because many waves including light will travel away from the filament in a circular motion and not straight lines directly towards the solar panel. As a conclusion, the further away the light is, the fewer rays will hit the panel, and the less voltage will be generated.
In the second half of the experiment, we kept the distance constant but utilized different colors. It was revealed that changing the colors of light would affect the solar cell output as each color of light has a different frequency. We could determine this from Einstein’s theory of photons being directly proportional to frequency. The theory states that Energy=(Planck’s constant*speed)/Wavelength.All the colours have the same speed, but various wavelengths, which, according to the equation above, modifies the value for energy (solar output). As long as the wavelength is the denominator of the equation, we can say “the larger the wavelength, the lower the energy” (Such as the red light in the experiment. See chart below). However, lights that have large energy photons must have low wavelength such as the green color.
The chart confirms that the voltage output from the green light is greater than the red light.
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