Objective

The objective of this experiment is to determine if changes in intensity of light affect the output of solar cells.

Materials and Equipment

To do this project you will need:

• a small solar cell,
• a volt meter,
• an LED (light emitting diode),
• a switch,
• a reflector light socket, and
• 5 light bulbs (15 watts, 40 watts, 60 watts, 75 watts, and 100 watts).

Experimental Procedure

Wire the volt meter and the LED together. Then wire those to a solar cell. Next, place a light bulb in a reflector lamp and shine it on the solar cell. Finally, measure voltage and current. Be sure to keep the reflector a constant distance from the solar cell. Each light bulb produces a different number of lumens of light. What is the relationship of lumens to the voltage output by the solar cell?

Variations

• Test solar cell power output as a function of the angle of the incoming light. Keep the distance and brightness of the light source constant, but vary the angle of the incoming light.
• Another variation would be to measure the power output of the solar cell as a function of the ambient temperature (see the Science Buddies project: A Cool Way to Make Electricity: Solar Cell Power Output vs. Temperature. To vary the intensity of the light, you could use light bulbs of the same size and shape, but different wattage. For a more advanced project, you could do background research to learn how to measure the intensity of the incoming light, perhaps using a photographic light meter.
• A more advanced project idea would be to measure the power output of the solar cell as a function of the color of the incoming light. You should do background research to learn how light energy varies with wavelength. You will also need to know the spectral characteristics of your light source. For this reason, it would be a good idea to use sunlight for this project. You can get a booklet with 100 color filters for about $10 plus shipping. A search on "color filter booklet" should turn up multiple sources.

Credits

Nicole L. Corlett

Last edit date: 2006-01-09 19:40:24