2004 Science Fair
Purpose:
The purpose of this project is to see what effect, if any, the position of solar cells have in determining the amount of energy produced.
Materials:
3 2x4cm solar cells
red and black 20-gauge wire
3 dowels
wooden base
6 screws
solder
soldering iron
black paint
glue gun
screwdriver
digital multimeter
data log and penQuestion: Which is most efficient, a solar cell that is at a 45-degree angle, a solar cell that is level (facing up), or a solar cell that is at a 90-degree angle.
Hypothesis: I believe that the solar cell that is level will get the most sunlight and so it will be the most efficient.
Constructing the test equipment:
- Drill three holes in the wooden base, each the diameter of the dowel rods.
- Cut the end of one dowel rod to make a 45-degree angle.
- Insert dowels into the holes.
- Paint the base and the dowels black so reflected light won’t influence results.
- Use screwdriver to put two screws in front of each dowel rod.
- Solder one red wire and one black wire onto the backs of the solar cells.
- Attach the solar cells to the top ends of the dowel rods with a hot glue gun.
- Attach each wire coming from the solar cells to one of the two screws in front of it.
Testing procedures:
- Set a digital multimeter to the voltage setting.
- Touch the red lead to the screw with the red wire and the black lead to the screw with the black wire for the first solar cell.
- Check and record the reading along with the date and time of day.
- Repeat for the other two solar cells.
Results:
The results between the 45-degree angled solar cell and the level solar cell were close. Both positions were better than the solar cell placed at at 90-degree angle. The highest test result for the 90-degree solar cell was below the lowest readings for the other two solar cells.
In two tests the level solar cell tested higher than the 45-degree solar cell. The first time was a partly cloudy day and I had trouble getting good readings. The second time it tested higher was at noon.
One time the 45-degree solar cell and the level solar cell gave the same test results. During that test the sun was at a 46-degrees, so both solar cells were getting sunlight at almost the same angle.
Tests done later in the day when the sun’s altitude was below 10-degrees showed the widest range of results.
Conclusion:
My hypothesis that the level solar cell would have the highest readings was incorrect. Although it tested high at noon, overall the 45-degree solar cell tested higher throughout the day. I was surprised at the results and think that the level solar cell might still do better if the tests had been done closer to the equator.
I would have liked to have taken more readings but I had two problems. In the beginning my testing was delayed when my cat knocked the test equipment off a table and broke one of the solar cells. The first day I tried a test was partly cloudy and the readings kept changing. After that, I decided to only take readings on clear days so bad weather lowered the number of days I could test.
My conclusion is that for my latitude (N85.491845), the solar cell fixed at a 45-degree angle was the most efficient at converting sunlight to electricity. My second conclusion is not related to the experiment itself. It is that I shouldn’t leave test equipment with dangling wires where my cats can reach it.