Our hypothesis was that the electrical output of a solar panel would decrease as the cloud cover increased. Our independent variable was the weather condition while the dependent variable was the electrical output. Our hypothesis was accepted. For the condition of precipitation we took measurements on four different days with an output ranging from 8.58 volts to 15.96 volts and light intensity ranging from 150 to 1250 foot candles. For overcast weather we took measurements on three different days with an output ranging from 12.35 volts to 17.30 volts and light intensity ranging from 750 to 1750 foot candles. For partly cloudy conditions, we took measurements on two different days with an output ranging from 16.61 volts to 19.36 volts and light intensity ranging from 1600 to 2750 foot candles. Finally, for sunny conditions, we took measurements on four days with an output ranging from 20.30 volts to 21.27 volts and light intensity ranging from 3750 to 4750 foot candles. Thus, we found that as the light intensity decreased, the electrical output decreased significantly.
We also calculated the standard deviation for each of the weather conditions. Using the ANOVA method (p<0.05) we determined that our results were not due to chance alone, but to the manipulation of our independent variable. We can state with 99.99% confidence that our results are statistically significant.
Furthermore, we calculated the efficiency for each weather condition. We found that as the light intensity increased, the efficiency of the solar panel to generate electricity decreased.
Finally, our highest energy output was 21.27 volts which is 89% of the solar panel’s stated maximum output of 24 volts.