How clean is solar power?
Solar panels does not emit green house gases like carbon dioxide while generating electricity, producing no harms to the environment at all like fossil fuels. However, in process of melting and purifying the slicon, significant amount of heat is needed for it to transduce and absorb sunlight. (melting point of slicon: 1414 celsius) Although energy is needed in forming panels, the environmental benefits of installing solar panels are enormous as it replaces electricity that would otherwise be generated by burning coal or gas. A team of researchers found that solar panels made today are responsible for around 20 grams of carbon dioxide per kilowatt-hour of energy they produce over their lifetime. Compared to 1975, there has been a significant decrease from 400-500 grams. Likewise, the amount of time needed for a solar panel to produce as much energy as was involved in its creation has fallen from about 20 years to two years or less. As more panels are made, the manufacturing process becomes more efficient. The team found that for every doubling of the world’s solar capacity, the energy required to make a panel fell by around 12% and associated carbon-dioxide emissions by 17-24%. This shows that solar power is becoming the most efficient and productive energy source for replacing fossil fuel, not only having envirnonmental benefits but also having great efficiency and production. References: http://www.economist.com/news/science-and-technology/21711301-new-paper-may-have-answer-how-clean-solar-power World's largest solar power plant in India:
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Based on the our plans, my mentor and I took the solar panels to the physics classroom to try exposing it to different light sources. Like the photo below, we connected it to the logger pro and the voltmeter probe. As soon as we connected the voltmeter probe, the logger pro showed the number 6V, which is the electricity (voltage) solar panel has when it is placed in the classroom without any direct light source. We then placed the panel below the light stand and the logger pro went up to 10V. We also placed the panel near the window for it to directly get the sunlight but the logger pro again showed 10V. A major problem showed up as we realized that the maximum voltage the voltmeter probe could go up to was only 10V. This meant that every value exceeding 10V could be only shown as 10V in the logger pro because of the voltmeter probe. As we encountered this unexpected problem, we weren't able to measure the accurate voltage. So we asked Mr Evans for other voltmeter probes that has higher maximum voltage and we are planning to continue our experiment with a different probe for more accurate results later on.
My mentor and I are planning to set up a small experiment in order to fully understand how solar panels work before getting on to our actual series of experiments. By using the solar panel we bought, we are testing it by exposing to various light sources. We are planning to connect it to the logger pro and voltmeter probe in our school to see the immediate voltage changes that would be graphed in logger pro as we move the solar panel around to different places. For example, we would start off by just leaving the solar panel where it is, not directly facing any light sources. Then, we would move it up to the light stands or even near the window where the sun shines through to gradually increase the light intensity it gets. I assume that the voltage would increase and show drastic changes as soon as we change the light source.
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Irene Jeong's signature project:Conducting various experiments using school's solar panel to find out the optimum environment for maximum efficiency of photovoltaic cells Archives
May 2017
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