ABSTRACT: For my long term science experimentation project, I compiled data on alternative energy sources. After reviewing previous studies done on renewable energy, I found that solar and wind sources were the most widely used, so this project compares those two specific fields. Using a small photovoltaic solar panel and one wind meter, I collected data on the two aforementioned fields on a regular-as-possible basis. After a two month period of data collection, I graphed the data and used it in comparative analysis. Since the data for the two sources was collected using different units, the high-output consistency, and thus efficiency of the two was compared. After studying the data it becomes clear that my hypothesis was correct, that in fact solar energy is more efficient and better suited for widespread use.
INTRODUCTION: Although alternative energy sources have not yet caught on in mainstream America, many advancements in the field are currently being made. The largest study sponsored by the government is the National Renewable Energy Laboratory, (NREL). The NREL conducts many large scale tests in order to make renewable energy devices more accessible to the common man, especially in respect to solar and wind energy. One experiment which is extremely relevant to this project is the NREL's Outdoor Test Facility, which is used to test photovoltaic devices much like the one used here. A photovoltaic device uses semiconductor material to convert sunlight directly into energy. This technology has a large advantage over other solar energy equipment in that the sunlight is turned directly into heat. Many other solar devices have the sunlight stored in liquid, or stored as latent heat, extending the process. Also, photovoltaic panels are very thin, can be very small and so can be used in many different situations. In fact, photovoltaic solar panels are already being used to power satellites, emergency highway call boxes, traffic signs, street lights, and calculators. The list will not stop there, however, because as the technology is further developed, so will the uses. With the work that the Outdoor Test Facility is doing right now, it is predicted that in the near future photovoltaic devices could provide all the daytime energy for a home, at half the current cost. Like solar technology, wind power is also starting to be utilized in some places. The flat lands of places like California, North Dakota, and much of South America are ideal spots for wind "farms". The major problem with wind energy, however, is that to get a usable amount of energy from the wind, extremely large metal turbines are required. For these immense machines to be powered, the breeze needs to be above 15 mph (on average). Fifteen miles per hour may not seem like a lot, but in many places natural land forms prevent the wind from reaching that standard very often.
PROBLEM: As we move into the twenty-first century we need to start conserving our natural resources, yet a definitive stand on renewable energy has not yet been taken. What form of alternative energy is more efficient, solar power or wind power?
HYPOTHESIS: I believe that solar energy would be more efficient than wind energy. I feel this way because some sunlight always hits the earth's surface and can be harnessed, but there needs to be fairly heavy winds for wind power to be used. By conducting this experiment, I will prove my theorey.
MATERIALS: The materials used in this experiment were: one 3/4 in. by 1 3/4 in. photovoltaic solar panel, one 12-range electrical multi-tester, and one wind meter. The photovoltaic panel is connected to the electrical tester.
PROCEDURE: At 3:30 pm, the solar panel (connected to the electrical tester) is placed on the deck of my house. The panel is faced in a westward direction, and tilted at a forty-five degree angle. The electrical tester is set on "50 DC mA", and the output is read. After this, the wind meter is used to determine the wind speed, while standing at the same spot from whic the solar data was taken. The results from both operations are then recorded. The experiment is conducted as regularly as possible over a period of two months (January-February).
DISCUSSION OF RESULTS: Although there is heavy fluctuation on both the solar and wind power sides, the data (graphic representation especially) clearly show that solar energy comes out as the more efficient choice. There was high-output (15+) for solar energy on Jan. 1, 8, 12, 15, 23, 26, and 29, and on Feb. 2, 6, 9, 15, 18, 20, and 23. While for wind energy, the only high-output (15+) days were on Jan. 7 and Feb. 21, 22. This staggering difference of 14:3 high-output days is truly amazing and clearly proves the hypothesis to be correct. The line graph shows the large margin between the two sources over a long period of time (two months). While the solar energy line does have it's peaks and valleys, there is still a semi-consistent area of high-output for the photovoltaic panel. The wind speed was more consistent, but not in a positive way. This experiment clearly shows that the wind speed is simply not high enough on average, to support wind energy equipment in this area.
CONCLUSION: This experiment has proven very clearly, that solar power is a better alternative energy source for this area. While the wind is more consistent, only three out of the twenty-six test days would actually provide usable energy. Solar energy is much more practical for people in the north-eastern part of the country, mainly as a result of the abundance of trees. Trees hinder both the flow of wind and sunlight, but the result is not catastrophic for solar energy. With wind power, there needs to be at least fifteen miles per hour winds, or else no usable amount of energy can be gained. With solar energy, however, some sunlight always reaches the surface of the earth, and that "some" can still be turned into energy, even if it is not too great an amount. Also, the treeline doesn't affect the sun's rays that much, as the branches and leaves do not block out the sun completely. An even greater reason why solar energy is more practical, is the proximity of the equipment to the home. With wind power, the large turbines are stationed far away, in wind "farms". The farms must then be connected to the home through an intricate system of wires, etc., which drives up the cost of the entire system. Photovoltaic panels, however, are located right at the home of the user. The panels are very small, thin, and can be placed on top of the roof as shingles - with a direct connection to the house. The data of this experiment, plus the simple logistical facts all prove the hypothesis to be true: that solar energy is more efficient than wind energy.
SOURCES OF ERROR: The fact that not all the data was collected at exactly 3:30 pm could have caused a slight variance. The wind meter that was used was not incredibly precise.
BIBLIOGRAPHY: NREL. "Advancing Photovoltaic Technology." Online. Available HTTP: 4 Dec. 1996. NREL. "Converting Sunlight into Electricity." Online. Available HTTP: 4 Dec. 1996. "Renewable Energy: Photovoltaics." Online. Available HTTP: 4 Dec. 1996. "Renewable Energy: Solar Thermal." Online. Available HTTP: 4 Dec. 1996. "Renewable Energy: Wind." Online. Available HTTP: 4 Dec. 1996. "Solar Heat Storage." Online. Available HTTP: 4 Dec. 1996. "Solar Energy Breakthrough." Online. Available HTTP: 4 Dec. 1996.