Solar energy, what exactly is it? I’m sure we’ve all heard of it but do we really know what its all about and who is works. Well thanks to my in class solar call lab I now have a better understanding of solar energy.
Solar energy is radiant energy emitted by the sun. Its the energy received by the earth from the sun. This energy is in the form of solar radiation, which makes the production of solar electricity possible. Seems quite simple to understand right?
Our lab put solar energy to the test! Our goal for this lab was to find the relationship between light intensity and voltage and also between light’s wave length and voltage. To prove that greater distance results in a decrease of both light intensity and voltage.
Current-is a moving charge
Voltage- is the amount of energy per charge required to move charge around a circuit
The common denomenator between current and voltage is that it is seen in an electrical circuit, it is voltage that drives current. Go figure
photovoltaics (which are solar cells) I just wanted to use that word so I sounded smarter. These cells provide a direct current of constant electricity. The amount of voltage and current of them is dependent on wavelength of light which is the length of a single cycle of the wave. Higher intensity means greater current and voltage because of the increase in the amount of generated photons.
Stuff we used :
• One voltage probe
• One NXT adaptor
• NXT with light sensor
• One light source
• Labview VI
• Ruler
• Colored film filters (red, orange, purple, blue)
• Excel sheet & one solar cell
Instructions:
1. With no light
2. With light 0 cm away
3. Distance 1 (varied by student groups): 5 cm
4. Distance 2 (varied by student groups): 10 cm
5. Distance 3 (varied by student groups): 15 cm
Part II: Repeat with 4 colored filters – we used red, orange, purple, and blue
Part III: Graph Results – voltage vs. intensity (varies by distance)& voltage for 4 different filters
Ok so here comes the intering stuff, our results! yay!
our results with no filters
No Light 0 cm 5 cm 10 cm 15 cm
-0.01469 0.47285 0.46002 0.42153 0.30606
-0.02752 0.54983 0.42153 0.39587 0.30606
-0.04035 0.47285 0.4087 0.47285 0.25474
-0.04035 0.51134 0.4087 0.48568 0.30606
0.06229 0.51134 0.46002 0.42153 0.24191
-0.01469 0.47285 0.4087 0.38304 0.37021
-0.02752 0.537 0.44719 0.39587 0.42153
-0.02752 0.51134 0.42153 0.48568 0.34455
-0.02752 0.46002 0.4087 0.44719 0.35738
0.01097 0.49851 0.39587 0.39587 0.44719
avg:-0.01469 avg:0.499793 avg:0.424096 avg:0.430511
avg:0.335569 (15 cm)
The first column shows voltage with no light. You can see that results are mostly negative in number. This means that when no light is present, voltage is at its lowest because light is not as quckily detected.
The second column shows results when light is 0 cm away, we held the flashlight directly against the solar cell. Here, voltage, and light strenth, is greatest. This is evidence that the closer/more direct light is to the cell, the greater voltage/light intensity will be. With the following three sequences, voltage/light intensity decreases with increased distance away from the solar cell. So this proves the theory that greater distance results in a decrease of both light intensity and voltage.
Here are our results when we used colored filters
Red Orange Purple Blue
0.4087 0.49851 0.34455 0.39587
0.39587 0.47285 0.39587 0.37021
0.49851 0.47285 0.31889 0.37021
0.51134 0.48568 0.34455 0.35738
0.47285 0.46002 0.2804 0.26757
0.48568 0.42153 0.31889 0.25474
0.4087 0.46002 0.35738 0.26757
0.39587 0.47285 0.29323 0.2804
0.46002 0.47285 0.30606 0.29323
0.39587 0.48568 0.29323 0.29323
avg:0.443341 avg:0.470284 avg:0.325305 avg:0.315041
Filters show voltage/light intensity from greatest to least: orange, red, purple, blue. From these results we found that the darker the color value of the filter, the less light it will let through. The solar cell let through most light from the orange and the least from the blue. This means that bright/lighter light is more easily detected when passing through lighter/brighter color values than through darker/deeper color values and that is why the voltage/light intensity was greater for orange and red than it was for purple and blue. Filters only transmits one wavelength of color to pass through when no filter allows all wavelengths to pass and that is why voltage/light intensity is greater with no filter versus with a filter regardless of color.
See you on the next lab post my fellow blogers!
What I liked about this post is how unbiased it is. You give both sides of the arguments and the pros and cons of each. Your post makes readers more able to construct their own views on the matter because they are aware of all the facts.