I am in 7th grade and doing a science fair project using different solar panel arrays. I have 3 different configurations with 6 mini panels connected. For each configuration, I have all the positive wires connected and all of the negative wires connected. I am using a multimeter to measure the voltage and the amps. If I multiply the amps times the voltage, will this give me an accurate indication of the output for each of the three configurations? Thank you in advance for your assistance!
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Unfortunately, it's not that easy.
If you connect different loads to a cell, the voltage and current through the load will (of course) be different. If you draw a curve of all that current vs. voltage points, it will look like the violet one on this picture:
If you measure the voltage with a multimeter (no other loads connected), no current is flowing through it, and you get Vmax.
Now, just multiplying Vmax and Imax gives the light blue rectangle (partially overlapped by the yellow one). But this is no correct value because as said, the current at Vmax is zero, and so is the power!
If you take your measurements with the loads and draw a curve of (voltage * current) vs. voltage, you get the green curve. It shows what power is delivered by the cell at what voltage. You can clearly see there is a maximum, and the according power is the yellow rectangle.
So, the yellow rectangle shows the real maximum power, which is much smaller than what you calculate by Vmax*Imax.
I think you can measure Vmax and Imax for all your configurations of the cells, and it gives sort of hint which one gives the most power. But it may also be interesting to apply several different resistors and to this voltage and current measurement.
By turning the knob, you can change the resistance between one of the outer and the middle terminal. It would be best to have two multimeters, one to measure voltages and one to measure currents. Connect it like this, leaving one of the outer terminals unconnected:
and you can easily turn the knob a little, read current an voltage, and enter it into an excel sheet to generate curves similar to mine.
The potentiometer must be able to handle the maximum power your cells may deliver, which can be estimated by Imax * Vmax (per cell). I'm also not sure what resistance to recommend, may be you use two, one in the range of 100kOhm to 1MOhm, an one in the range of 1-10kOhm, to be able to measure with low and high loads. May be, you have someone to ask for this stuff, like a teacher?
Further thinks you could measure (with one cell):
As said in the other answer: It's really nice to hear that you are interested in this stuff at that age, and I really encourage you to keep on. May be, you can show us your results later on?
dont forget that your panels can be in series and then in parallel.
i think the way you have your setup it is considered "parallel".
just my 2 cents worth.
btw glad to see that someone in 7th grade is actually trying to be smart and learn about science. if i had it to do all over again, I would take every single advanced class(math, science, english, etc...) whats the worse that could happen ? you learn ?
You may want to try a reasonable number of combinations of series and parallel for the 6 panels to see which one produces the most interesting results (you may be surprised by the answer). The options are:
In my "pictures", () means to connect wires, so (++) means 2 reds together and (--) means 2 blacks together and (--++) means 2 reds and 2 blacks of different panels together. I also attempted to drawn the panels as numbers, +1- is panel one with a red wire "+" and a black wire "-".