Objective: The objective of the experiment we performed was to test the correlation between the intensity of the light shone at the solar cell and the output of the cell. The test was then repeated with different colored pieces of transparent plastic applied to the surface of the solar cell. The results were used to compare how different wavelengths of light received by the solar cell affect the output value.

Materials used: Lego Mindstorm Voltage Sensor, Solar Cell, Flashlight, Ruler, Pieces of Colored Transparent Plastic.

Experiment and data:

In a small group we set up the equipment:

1. We turned over the solar cell, so it faced down to measure the base voltage without any light applied (10 measurements);
2. The flashlight was then set at a particular height and 10 measurements of voltage output were made (this part was repeated for different heights);
3. The above-described procedures were then repeated for the solar cell covered with different colored transparent pieces of plastic (10 measurements without any piece of plastic applied at a certain height, then 10 measurements for each different color at the same height).

Analysis of the data:

The data we obtained support our thesis that the intensity of light affects the output. The graph shows that the data follows a polynomial trend-line of second order with R^2 value of 0.97 (extremely close resemblance). This result is also in accordance with our theory as we would expect the distance squared to be inversely related to the output value.

The colored light component of the experiment did not prove our thesis that altering the wavelength of light affects the output. The highest output was for the white light. The second highest output was surprisingly enough for the red light, which happens to have one of the highest wavelengths or, in other words, the lowest energy. The blue light, which has the highest energy among all lights we tested, resulted in the output smaller than the output for the green light, which has a higher wavelength and a lower energy. The mistakes in the results we have gotten can be attributed to the qualities of the plastic we used or other unknown variables.

Applications of the experiment in the real world:

The solar cells are gaining popularity across the world with Bangladesh taking the lead in number of individual units served (Yee). Thanks to the simplicity of the technology, international subsidies, and micro-financing companies, Idcol (private for-profit company, main distributor of solar cells in Bangladesh) is able to provide thousands of poor and off-grid people with electricity. The management techniques, accessible loans, and trust-worthiness coupled with reputation of small micro-credit companies (local distributors of the solar cells) made this unique phenomenon possible. In this example of solar cells applications, we can see how clean energy from the renewable sources is sometimes more profitable and accessible to low-income people than that from the fossil fuels.

Yee, Amy. “In Rural Bangladesh, Solar Power Dents Poverty.” The New York Times. The New York Times, 04 Oct. 2016. Web. 10 Oct. 2016.