Solar Cells and Clouds

  • What is the effect of clouds, shade or hazy skies on the performance of solar cells?

Recommended Items:

  • Digital multi meter
  • Solar cell
  • Gauzy fabric
  • Cardboard

Concepts used:

  • Solar cell performance

Background:

Solar cells are able to absorb light energy and convert it to electrical energy. The flow of this energy is called current. The greatest disadvantage of solar cells is that they cannot produce electricity when there is no light incident on them. It is interesting, therefore, to observe the effects of shade on solar cell performance.

In this experiment cloud cover and shading is looked at as it relates to the performance of the solar cell. Take a solar cell and expose it to either full sun or to bright light from a lamp. Attach the output of the cell to a digital multimeter to monitor the current produced by the cell. Next, shadow different parts of the cell and observe the effect on the cell output. Try shadowing increasingly more of the cell surface from left to right and right to left, from top to bottom and from bottom to top. Observe the effects of shadows on the solar cell output. Record the voltage output at different points of shading. The effect of hazy skies can be simulated by covering the solar cell with increasing thicknesses of gauzy fabric. In this case record the current output of the solar cell as more layers of fabric are added. What relationships do you see regarding the effect of hazy skies versus solid shadows on the performance of the solar cell? Which condition has a worse impact on the cell output? What does this mean in terms of building a solar panel system to power a home?