Walker Renewable

Purpose: The purpose of this lab is to learn how to build a solar collector and to also measure the results and to determine the efficiency of the thermal collector. Another purpose is to learn about solar collectors and renewable energy sources. Hypothesis: If the solar thermal collector is built correctly and placed in the right elements then the collector will operate with above 50 percent efficiency. Experiment: In this experiment I built a solar collector and placed it in sunlight. Then I funneled a liter of water through the solar collector continually filling up a cup on the output end. When that cup became full I poured the water back into the top collector. Every five minutes I recorded the temperature of the top part and recorded the information. I was able to use all this information to figure out the efficiency of the solar collector. For the second exercise, I used a multimeter and a silicone solar cell to analyze its collection of the Sun’s rays. I angled the solar cell horizontal to the Earth, perpendicular to the Earth and perpendicular to the sun to evaluate how those different angles showed different wattage.

Exercise 1: Building and Analyzing a Solar Thermal Collector Data Table 1. Measurements for the Solar Thermal Collector. Mass (g) of 50 mL of Density of water (g/mL) Beginning temperature Ending temperature Beginning air temperature Ending air temperature

water of water of water 48.5 .97 21.3 42.5 20.8C 26.4 Data Table 2. Water Temperature. Time (min) Temperature (°C) Weather changes 0 21.3 Slight breeze 5 25.5 No change 10 27.9 No change 15 29.8 No change 20 31.4 No change 25 33.0 Slight breeze 30 34.5 More wind 35 35.9 No change 40 37.4 No Change 45 38.5 No Change 50 39.4 Slight breeze 55 40.8 No Change 60 41.5 No change Questions A. Graph the data from Data Table 2 . Place temperature on the Y-axis and time on the X-axis. 0 10 20 30 40 50 0 5 10 15 20 25 30 35 40 45 Temperature of Water Time(minutes) Temperature(Celcius)

by the watt-hours the collector received in one hour and multiply by 100 to determine percent efficiency. 400(.07)=28 24.091/28=0.8604 .8604(100)=86.04 The solar collector operated with 86.04 percent efficiency. D. What are the sources of error that exist for calculating the percent efficiency of your solar water collector? The sources of error that exist for calculating the percent efficiency of my solar water collector is trying to pick a value to use for a decently warm fall day. I chose to use Sunny winter/ partly cloudy summer for mine. Another error can be making sure no water is lost during the experiment and eliminating wind. E. How would you make the collector more efficient? I could make the collector more efficient by spending more time making sure the solar collector is sealed as much as possible. I would shorten the tubing to allow for better flow of water as well.

Exercise 2 : Analyzing a Silicon Solar Cell Data Table 3. Voltage, Amperage, and Wattage Data from a Silicon Solar Cell. Solar cell parallel to Earth Solar cell perpendicular to Earth Solar cell perpendicular to Sun’s rays Voltage .55 .59 .59 Amperage .0069 .0155 .1537 Wattage .003795 .009145 .090683 Data Table 4. Calculated Values from Using a Silicon Solar Cell. Maximum Wattage/Power (W) Area of PV cell in m 2 Power density (W/m 2 ) 0.090683 0.0004m 2 226.7075 Questions A. What difference, if any, was there among the different positions of the solar cell? What does this tell you about the optimal way to position solar panels for highest electricity production? There was a significant difference between the different positions, parallel to the earth was the least efficient, perpendicular to the Earth is more efficient but the most efficient was perpendicular to the Sun’s rays. This shows that solar panels should be positioned perpendicular to the Sun’s rays for best electricity production. B. How many solar cells of the type you worked with would it take to light a 100 W bulb for one hour? (Assume that the bulb is used during the middle of the day, or that you have a way to store the energy the solar cell produces during the day for use at night or when it is cloudy.) How many square meters would that require? This would require .4411m 2 to power a 100 watt lightbulb for an hour. 100/ (.090683)=1,102.743(0.0004)=.4411 Evidence: It takes 100 watts to power a 100 watt lightbulb for an hour. The maximum wattage of the solar cell I used was .090683 W when perpendicular to the sun’s rays. I took 100 watts divided by maximum wattage and then multiplied the result by the area of our solar cell to discover how many square meters of our solar cell would be needed to power the lightbulb.

Source: Solar . Energy.gov. (n.d.). https://www.energy.gov/solar Solar energy . Education. (n.d.). https://education.nationalgeographic.org/resource/solar-energy/ Encyclopædia Britannica, inc. (2023, October 30). Solar energy . Encyclopædia Britannica. https://www.britannica.com/science/solar-energy