On our make-up class day, at 9:30 in the morning, my group began experimenting once again with NXT and the LabView program. This time, our purpose was to look at light energy. Much has been made of the sustainable possibilities of solar energy as a totally green, efficient alternative to fossil fuels. To better understand the concepts at work in solar energy, we took to the lab.
It was discovered not so very long ago that light is actually energy, as well as a particle. This weird phenomenon of light has led to light particles as being referred to as “photons.” Most of the photons that we would use for energy to power our cities and machines would come from the sun, if the technology became more developed. However, on the cloudy Friday in Archer where we conducted the experiment, sun-photons were simply not an option. We relied on photons from a weak flashlight to generate energy, and though the magnitude of the energy was nowhere near what the sun could have provided, at least the flashlight served to illustrate the basic concepts of solar energy.
The experiment was two-fold: in part one, our group moved the flashlight various distances from the solar cell connected to LabView. This mini-solar cell was our “receptor,” measuring how much energy we were providing it with from the flashlight every 30 seconds. Our hypothesis was that the closer the flashlight was to the solar cell, the greater the energy would be. This proved sort of right, as a few of our trials didn’t support this theory. Likely the result of human error anyway, we threw out the suspect data and ended up with the following results: with no light, there is no energy. At 1 inch away from the panel, the flashlight provided 0.331V, and decreased the further away we shone the flashlight. We made a chart and graph in Excel to show this trend:
The second part of the experiment required us to keep the flashlight at a constant distance from the cell, and place over the light a colored filter. Using three different color filters, placed 2 inches away from the cell, we measured what effect this had on the energy produced. Here is a chart of our findings.
It would seem that these filters have the ability to filter out certain wavelengths of the visible spectrum. Allowing only one portion of the visible spectrum through, we saw which colors had higher wavelengths and therefore more energy than others. Green was the weakest, blue was stronger and the pink-ish magenta filter gave the most energy. This makes sense and is in keeping with our knowledge of the visible spectrum.
