I'm helping my son with his 7th grade science project. We've had a good deal of fun with our experiments with Solar Arrays and charging 12 volt UPS batteries! But, I am not sure how to interpret the data! Our original hypothoesis was that the lenght of the wire between the solar panel and the battery would effect the voltage charge the most. We do NOT think that was true! We just need to get some good charts out of the data to show something that we learned!
As per my observation, you need to visualize different configurations. WEKA can be used to visualize this type of things where it automatically stack multiple Graphs side by side to find trends. There are other features as well.
Yo can further explore here