biology lab report week 4

biology lab report week 4
Lab 4 Energy Sources and Alternave Energy 44 Energy Sources and Alternative Energy Concepts to Explore  Energy  Non-renewable sources  Passive solar energy  Active solar energy  Photovoltaics  Wind energy Introduction Energy i s es s en ti al f o r li f e t o ex i st i n an y en v i r o n m ent . As h u m an s , w e c o n s um e h u g e q u an t i ti es o f energy every day. This, however, comes with many consequences. Although energy is abundant every-where, useful energy is much more difficult to produce and less efficient for our daily activities. Over 90% of produced energy comes from non-renewable resources. These include oil, natural gas, coal, and uranium. Not only are our sources of fossil fuels and other non-renewable energy sources depleting, but many of these sources produce toxins that are harmful to our bodies and the environment. Fossil fuel depletion, deforesta-tion, pollution, and global warming are just a few negative effects that come from the combustion of many non-renewable energy sources. Non­Renewable Sources Oil is derived from the remains of plants and animals that lived in aque-ous environments millions of years ago. Over very long periods of time, the heat from the Earth’s core and the pressure from the sand, silt, and rock that deposited on top of it turned the remains into crude oil. Scien-tists and engineers explore areas to find rocks that indicate the pres-ence of oil underneath and drill through them to tap into the reservoir holding the yellowish-black substance. After the oil is drilled, it is sent to a refinery to be separated into usable petroleum products, most of which are used to produce energy. These include: heating oil, jet fuel, heavy fuel oil, liquefied petroleum gases, and gasoline. Coal is another non-renewable energy source that is derived from sedi-mentary rock comprised mainly of carbon and hydrocarbons. It takes millions of years to create and form from dead plants that became trapped under dirt and water. There are four main types of coal: anthra-cite, bituminous, subbituminous, and lignite. Coal is classified into these groups based on the amount of car-bon it contains. When coal is buried less than 200 feet underground, surface mining technologies can be ? Did You Know… The following products are made from petroleum?  Ink  Deodorant  Crayons  Dishwashing liquid  Eyeglasses  CDs and DVDs  Tires  Ammonia  Artificial heart valves 45 Energy Sources and Alternative Energy used to extract it. However, it if is deeper than 200 feet, underground mining is performed to reach and ex-tract the coal. More than 90% of the coal mined in the US is used for generating electricity. Even though coal is an inexpensive fuel source, it is important to remember that mining alters the topography and also can cause secondary pollution to waterways and the air. Similar to oil and coal, natural gas is produced from decaying plant material over very long periods of time. It is used in industrial and residential arenas for heating and electricity. Although natural gas is a relatively clean-burning fossil fuel, it is not without harmful environmental impacts. While products from oil, coal, and natural gas help do many things, finding, moving, and using them can harm the environment through air, water, and other secondary pollution. There are many ways that we can reduce the amount of energy consumed in our daily lives. Proper use of insulation, energy efficient light bulbs, pro-grammable thermostats, carpooling, and driving the speed limit can all help conserve energy, the environ-ment, and money! Two major forms of renewable energy are also being utilized – solar and wind energy. Earth receives most of the sun’s energy through forms of light, which can be used to minimize dependence on non-renewable sources. Solar energy can be converted into heat and other forms of energy, such as elec-tricity.The sun’s light is Earth’s most abundant source of energy and is also free of cost. For these reasons, scientists have studied ways to convert and harness the energy of the sun for centuries. There are four major forms of solar energy: passive, active, photovoltaic, and solar thermal electric energy. Each form of solar en-ergy has its unique set of advantages and disadvantages, but used properly can help in the conservation of energy and our planet. Passive Solar Energy When the sun is the only moving object and source of light and/or heat in energy transfer, the process is called passive. This means that no electricity is produced and only the sun is used to transfer energy to an-other object or group of objects. Passive solar energy is utilized in many households and buildings. Window placement, insulation, and ventilation are key components to properly utilize the sun’s power in order to keep cool in the summer and warm in the winter. Proper construction planning is key for these situations. Active Solar Energy Active solar energy, al s o k n ow n as act i ve so l ar h eati n g , i s si mi l ar t o it s p as s i ve c o u n t erp ar t i n t h e way that it captures energy from the sun. However, it goes one step further and uses a liquid to store and transfer the energy. Active solar heating systems often use the sun to heat an enclosed fluid, such as water. Once heated the fluid can be stored for later and used the next time someone needs to take a hot shower! These systems often use pumps to move the fluid during the heat transfer process and can become much 46 Energy Sources and Alternative Energy more complicated. This makes active solar heating less efficient because pumps require additional power to run. Photovoltaics When electrical energy is produced directly from the energy of the sun, photovoltaic (PV) cells are used. These cells are very common and often found on top of street lights, used in solar powered calculators, resi-dential homes, and watches. PV cells consist of tiny strips of semiconductors, such as silicon, which are joined together. When the sun strikes these strips the material becomes excited. If there is enough energy present, electrons are emitted from the excited atoms. This flow of electrons produces an electrical current, which can then be used as energy. Photovoltaics can be very expensive in large applications, but cost has continuously fallen as the technology is enhanced. Focusing solar energy using mirrors can help intensify heat transfer. This ancient technology has recently Figure 1: Several different designs of wind turbines exist, but the most common looks like an oscillating fan or wind mill. All of the different styles of turbines try to maximize the efficiency of the turbine at different wind speeds. 47 Energy Sources and Alternative Energy been utilized in large scale projects to produce electrical energy. In this process, reflected sunlight is focused on pipes of oil, which are then heated. Oil is used because it is much more conductive than water and can be heated with greater ease. The heat in the oil is then transferred to water and creates steam. This steam spins a turbine to create an electrical current. Converting the sun’s energy in this manner requires larger areas of land but is very useful. Solar thermal electric energy can even be used to increase the efficiency of heat pumps and power plants. Wind Energy Solar energy is what drives our planet. Almost every living organism converts the sun’s rays into a useful form of energy. At a quick glance, there seem to be very few drawbacks to using solar energy. However there are some big issues with using solar power for energy. First, solar energy can only be used in places where sun-light is abundant and when it is available. Solar energy is not available at night and it would be pointless to put PV cells in an area where the sun rarely shines. Clouds can also create a problem when trying to capture energy from the sun. If you need power but have no light, you are just out of luck. Second, storing solar ener-gy is difficult and inefficient. This means that if you do not need the energy at the time it is converted, it will be wasted. Finally, the equipment involved in many solar devices is expensive and tough to maintain. With this being said, advancements are being made every day and solar energy continues to expand. Like solar power, wind power has many advantages. Unlike fossil fuels, wind power is clean, abundant, and free. Wind is even more abundant than energy from the sun since it can potentially be harnessed 24 hours per day. Wind energy uses a turbine to convert kinetic energy from the wind into mechanical energy, which in turn produces electricity. Just like solar energy, wind has its disadvantages. The major disadvantage is that wind is unpredictable. Alt-hough unreliability can be reduced by choosing proven locations, no one can precisely predict wind speeds over large areas of land. This uncertainty requires the use of backup energy sources and storage devices. Wind farms are also by nature very large and expensive. Their size makes them unappealing near populated areas, which means that they must be a great distance from the area they are actually supplying power to. Large wind farms can also disrupt radio, television, and phone reception. Although there are problems with wind energy production, the global power output due to wind has increased exponentially over the years. This statistic emphasizes the need for future development in alternative energy sources in order to maintain the planet we live on today. 48 Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining Note: This experiment takes 1 hour to prepare and 48 hours to observe. Please plan accordingly. Coal mining, particularly surface mining, leads to large areas of land being temporarily disturbed. Mines col-lect and conduct water that is in contact with pyrite, a mineral that produces iron and sulfuric acid when ex-posed to air and water. Limestone is often used to mitigate the effects of pyrite on water. In this lab, you will see first-hand the reasons why mine drainage can be harmful to the local drainage system if left untreated. Procedure 1. Record your hypothesis in post-lab question 1. Be sure to indicate what differences you expect to observe between the pure water, crushed pyrite, and the limestone. 2. Label the three 250 mL beakers, “Water,” “Pyrite,” and “Limestone.” 3. Pour 100 mL of water into each beaker using the 100 mL graduated cylinder. 4. Label the three 100 mL beakers, “Water,” “Pyrite,” and “Limestone.” 5. Remove 25 mL of water from each 250 mL beaker using the 100 mL graduated cylinder. Place the water in the corresponding 100 mL beaker. Add 5 mL of Jiffy Juice with a pipette to each 100 mL beaker and record the initial pH of each beaker in Table 1. 6. Place 1 heaping teaspoon of the crushed pyrite and the limestone into their corresponding 250 mL beak-ers. 7. Set the 250 mL beakers in a warm place for 48 hours. Be sure to thoroughly wash and dry the 100 mL Materials (3) 250 mL Beakers (3) 100 mL Beakers 100 mL Graduated cylinder 1 tsp. Crushed pyrite Limestone Jiffy Juice Permanent marker Measuring spoon Pipettes *Water *You must provide 49 Energy Sources and Alternative Energy beakers for use in Step 8. 8. After 48 hours, remove 25 mL of water from each 250 mL beaker using the 100 mL graduated cylinder. Place the water in the corresponding 100 mL beaker with 5 mL of Jiffy Juice. Record the pH after 48 hours in Table 1. Jiffy Juice pH Color Chart pH 1-2 3 4 5 6 7 8 9 10 11-12 50 Energy Sources and Alternative Energy Experiment 2: Solar Energy The sun’s energy is free, plentiful, non-polluting, and can be converted into electricity with the use of photo-voltaic cells. Also called a solar cell, these panels capture sunlight and emit a current that can be used to power many things, including the small motor attached to the solar panel in your kit. In this experiment, you will investigate how the amount and wavelength of light affect the generation of electricity. Procedure 1. Record your hypotheses in post-lab question 1. Be sure to indicate what differences you expect to ob-serve when the light sources, filters, and blockers are applied to the solar cell. 2. Record the weather of the day in the top of Table 2. 3. Draw a dot on the disk using the permanent marker, near the outer circumference of the circle. This will help you to visualize the rotation of the motor once it starts spinning. 4. Find an incandescent light source. Observe the efficiency of the solar cell as you hold it under the incan-descent light source. Vary the distance between the apparatus and the light source by moving the appa-ratus back and forth. Note: Incandescent light sources refer to light bulbs that contain a filament wire. They are typically shaped like an upside-down pear and screw into table lamps. Do not use a fluorescent or halogen light source. 5. Observe the efficiency of the solar cell as you hold it in Direct Sunlight. Record your observations in Table 2. Circle the option that best represents the speed of the rotations as follows: very fast (VF), fast (F), me-dium (M), slow (S), or no motion (NM). Materials Solar cell, motor, and rotating disk Permanent marker Red, green, blue and yellow filters (cellophane) Black construction paper Aluminum foil Protractor *Incandescent light source (fluorescent and halo-gen light sources are not suitable for this experi-ment) *You must provide 51 Energy Sources and Alternative Energy 6. Observe the efficiency of the solar cell when it is struck by sunlight at a 45 Degree Angle. Use the protrac-tor to measure the angle of the solar cell from the ground and record the speed in Table 2. 7. Use the black construction paper to shade the solar panel in three different configurations: 25% Shaded, 50% Shaded, and 75% Shaded. Observe the efficiency of the solar panel at each configuration and rec-ord your observations in Table 2. 8. Use the aluminum foil to create a Reflector that reflects sunlight onto the solar panel. This should not cov-er the panel, but enhance the amount of sunlight that hits the panel sur-face. Observe the efficiency of the solar panel with the Reflector and rec-ord your observations in Table 2. 9. Use the aluminum foil to create a cover for the solar panel. This should be placed near the top of the solar panel, but below the horizontal silver bar (see Figure 2 for a picture of the foil/panel set-up). 10. Fold a piece of the red cellophane over two times so that you have a piece of cellophane that is four-layers thick (it should be one quarter of the origi-nal size). 11. Hold the red cellophane over the exposed portion of the solar panel, and observe the motor for any change. Repeat this process with the yellow, green, and blue cellophane. Observe the efficiency of the solar panel when each color filter is used to cover the solar panel and record your observa-tions in Table 2. Figure 2: Step 9 reference. Note, your local weather cli-mate will affect the amount of coverage your solar panel needs. In general, more direct sunlight requires greater cov-erage. Figure 3: Each cellophane sheet should be folded into quarters to create the desired rotational effect.
biology lab report week 4
Lab 4 – Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining Coal mining, particularly surface mining, leads to large areas of land being temporarily disturbed. Mines collect and conduct water that is in contact with pyrite, a mineral that produces iron and sulfuric acid when exposed to air and water. Limestone is often used to mitigate the effects of pyrite on water. In this lab, you will see first-hand the reasons why mine drainage can be harmful to the local drainage system if left untreated.   POST-LAB QUESTIONS Develop hypotheses predicting the effect of pyrite and limestone on water acidity? Why would you predict these effects? Pyrite hypothesis = Limestone hypothesis = Table 1: pH of Water Samples Water Sample Initial pH Final pH Pyrite Limestone Water Based on the results of your experiment, would you reject or accept each hypothesis that you produced in question 1? Why? Pyrite hypothesis accept/reject = Limestone hypothesis accept/reject = Based on your data, what effect do you predict coal mining has on the environment? Answer = Based on your data, why would you use limestone to treat acid mine damage? Utilize at least one scholarly resource to support your suggestions. Answer = Experiment 2: Solar Energy The sun’s energy is free, plentiful, non-polluting, and can be converted into electricity with the use of photovoltaic cells. Also called a solar cell, these panels capture sunlight and emit a current that can be used to power many things, including the small motor attached to the solar panel in your kit. In this experiment, you will investigate how the amount and wavelength of light affect the generation of electricity.   Post-Lab Questions Develop hypotheses predicting the efficiency of solar energy from direct sunlight against the four variables tested. Direct vs indirect (at an angle) hypothesis = Direct vs reflected (using aluminum foil reflector) hypothesis = Direct vs shaded (covering the solar panel) hypothesis = Direct vs filtered (using color filtration) hypothesis = Table 2: Solar Energy Experiment Results Environmental Descriptor/Variable Observations (Each should be compared against direct subnlight) Weather Motor speed in direct sunlight VF F M S NM Motor speed at 45 degree angle VF F M S NM Motor speed with 25% shaded VF F M S NM Motor speed with 50% shaded VF F M S NM Motor speed with 75% shaded VF F M S NM Motor speed under reflectors VF F M S NM Motor speed under red filtration VF F M S NM Motor speed under blue filtration VF F M S NM Motor speed under green filtration VF F M S NM Motor speed under yellow filtration VF F M S NM Based on the results of your experiment, would you reject or accept each hypothesis that you produced in question 1? Explain how you determined this. Direct vs indirect accept/reject = Direct vs reflected accept/reject = Direct vs shaded accept/reject = Direct vs filtered accept/reject = Does increased exposure to the sun’s light produce more current? Explain how you know this based on your data? Answer = How could you increase the electricity generated by a solar cell during the day when the sun’s angle is constantly changing? Answer = Based on your data, could adding filters to solar panels increase the solar energy produced? Explain how you know this. Answer = References Any sources utilized should be listed here. © eScience Labs, 2016