How Many 12 Volt Batteries Will It Take to Effectively Power My Room With a 20 Watt Solar Panel for Two Consecutive Sunny Days?
James
C.
6th
Grade, Calvary Chapel Christian School, West Melbourne
Florida
Teacher: Bob Akers
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Hypothesis: A twenty watt solar panel and two twelve volt batteries will power my room for two consecutive sunny days.
Summary: My science fair problem was: How many batteries will it take to effectively power my room for two consecutive sunny days? I chose this problem because I was interested in how efficient solar energy really is.
My hypothesis was: A 20 watt solar panel and two 12 volt batteries can power my room for two consecutive sunny days. I compared my batteries to the rating of my solar panel. Based on the information on the battery cover, the batteries together have 210 amp hours. The solar panel would need to produce enough amps to allow the batteries to recover so that they could power my room the next day. My goal was to do this on sunny days but the weather did not cooperate. This variable did not affect the outcome of this project but did change how well the batteries recovered based on the voltage readings. In order to make the testing fair, I ran the same electronics daily that used the same amount of energy for the same amount of time. This experiment was performed three times which confirmed I had accurate results.
My testing confirmed that the solar panel and batteries could power my room for 2 hours on 2 consecutive days. This proves my hypothesis correct. One observation that I made was that the weather does affect the state of charge of the batteries. The cold weather made my batteries lose power more quickly making them less efficient. I have learned through this experiment how efficient solar energy can be. My family as well as others can reduce energy consumption through a small investment of time and money.
If I were to repeat this project, I would use three batteries to be able to increase my storage capacity. Even though my data supported my hypothesis, the data did show a steady drop in voltage which would eventually result in damage to the batteries. I would also be interested in building my own solar panel which would be able to produce more watt hours.
Conclusion: Testing concluded that the 20 watt solar panel and two 12 volt batteries could power my room for two consecutive days, proving my hypothesis correct.
