MY OWN DESIGN OF HYDROPOWER”STATION” O KA TIRA ENGMY OWN DESIGN OF HYDROPOWER”STATION” O KA TIRA ENG? WATCH THIS SPACE…… AIM/ OBJECTIVE To determine the best location on a dam to generate electricity by investigating how the height of water above a hole in the dam wall affects the length of the stream flow from that hole. Introduction Electricity is a big part of your life. Can you imagine not being able to turn on a light, the TV, the computer, or your video game console? What about having no way to easily wash and dry your clothes, or keep your food cold? When the power goes out in a big storm, it's a big deal! It is always a high priority for power workers to get it turned back on. From where does all that electricity come? Electricity is a secondary energy source, meaning that it has to be made from some other source of energy, like coal, natural gas, oil, nuclear power, wind, or water. When electricity is made from the force or energy of moving water—water that is flowing or falling—it is called hydroelectricity (hydro means "water"). Hydroelectricity has been around since the late 1800's. Today, hydropower is a popular way to generate electricity, supplying the world with nearly one-fourth of what it needs, and reaching more than 1 billion people. Hydroelectric power has several advantages. Unlike fossil fuels, water is a source of renewable energy, meaning that it can be naturally replenished at a rate faster or similar to the rate that people use it up. Hydroelectric power is also low-polluting, dams to harness it can create recreational lakes, and the power can help with flood control and irrigation. Its disadvantages are that it can damage animal habitats or ecosystems, and in a failure, can cause flooding, such as the Teton Dam and Johnstown flood catastrophes, which you can read about in the Bibliography. Engineers weigh all these advantages and disadvantages before deciding whether or not to build a hydroelectric power plant. Hydroelectricity is made through the flow or fall of water. A big, fast-flowing river, for instance, contains a lot of moving energy that provides enough water pressure to turn the blades of a turbine and run an electric generator. This same water pressure can also be created though through the fall of water from a great height. A dam is the way we store water and raise it to a great height to create water pressure. Dams are among some of the biggest manmade structures ever built. Figure 1. This photo shows the Hungry Horse Dam in the state of Montana. (Bonneville Power Administration United States Department of Energy, 2003.) got this picture from internet you can to look more on your own. by Thabang modiba Dams block the flow of a river or stream and create a lake or reservoir behind them, which acts as a source of stored energy (a battery is another example of a reservoir of stored energy). The dam raises the surface water up to a great height, giving it potential energy, the potential to do work. Water flows from the reservoir and through a dam by way of a special intake gate called a penstock. It's kind of like one of those water tunnels you slide through at a water park in the summer. Water rushes down the penstock and turns the blades of a turbine, which is connected through a metal shaft to an electric generator. As the turbine turns, giant magnets inside the generator rotate past copper coils and alternating current is made. This current is then transformed in a transformer to a higher-voltage current so the electricity can be sent over long distances to homes in cities far away from the power plant. Figure 2. This animation shows how a hydroelectric power plant makes electricity. (United States Geological Survey, 2008.) Thabang’s images What determines how much electricity a hydroelectric power plant can produce? There are several factors, but two of the most important are the water flow rate through the dam, and the distance from the surface of the reservoir to the penstock. These determine how much energy can be released when the water is lowered, in a controlled way, from the reservoir. You can approximate the hydroelectric power production of a dam with this equation: Equation 1: Power = Water Flow Rate × Acceleration Due to Gravity × Reservoir Height × Coefficient of Efficiency Power is in kilowatts (kW). Water flow rate is in cubic meters per second (m3/s). Acceleration due to gravity is 9.81 meters per second squared (m/s2). Height is in meters (m). Coefficient of efficiency ranges from 0 to 1, with modern power plants having the highest efficiency. In this power and energy science fair project, you will investigate how the distance between the surface of the reservoir and the penstock affects the flow out of the penstock. Do you think a deeper reservoir will create a different flow than a shallow reservoir? It's time to find out! Terms, Concepts and Questions to Start Background Research Hydroelectricity Hydropower Generate Fossil fuel Renewable energy Habitat Ecosystem Water pressure Dam Reservoir Potential energy Penstock Turbine Electric generator Magnet Alternating current Transformer Voltage Bernoulli equation Questions What are the advantages and disadvantages of hydroelectric power? What are the parts of hydroelectric power plant? How does a hydroelectric power plant make electricity? What factors are important in determining how much electricity a hydroelectric power plant can produce? What are the different types of dams? Bibliography( I USED THE FOLOWING SITES MFAN) These sources describe the parts of a hydroelectric power plant and how it makes electricity: Bonsor, K. (2009). How Hydropower Plants Work. Retrieved February 13, 2009, from http://science.howstuffworks.com/hydropower-plant.htm Energy Information Administration. (2008, October). Energy Kid's Page: Hydropower—Energy from Moving Water. Retrieved February 17, 2009, from http://www.eia.doe.gov/kids/energyfacts/sources/renewable/water.html Perlman, H. (2008, November 7). Hydroelectric power: How it works. Retrieved February 17, 2009, from http://ga.water.usgs.gov/edu/hyhowworks.html These articles describe two historic dam failures: Wikipedia Contributors. (2009, February 13). Teton Dam. Wikipedia: The Free Encyclopedia. Retrieved February 17, 2009, from http://en.wikipedia.org/w/index.php?title=Teton_Dam&oldid=270481818 Wikipedia Contributors. (2009, February 22). Johnstown Flood. Wikipedia: The Free Encyclopedia. Retrieved February 22, 2009, from http://en.wikipedia.org/w/index.php?title=Johnstown_Flood&oldid=272408495 This source discusses the Bernoulli equation, which describes the way liquids move and provides an equation for calculating the velocity of the stream flow from the height of the reservoir: The Millennium Mathematics Project Contributors. (2009). Testing Bernoulli: A Simple Experiment. Retrieved February 17, 2009, from http://plus.maths.org/issue2/bottle/index.html Visit these pages, from PG&E, a California power, gas, and electric company, for more information about electricity: Pacific Gas and Electric Company. (2002). Electricity Generation and Distribution. Retrieved March 4, 2009, from http://www.pge.com/microsite/pge_dgz/more/electricity_gen.html Pacific Gas and Electric Company. (2002). Alternative Energy Sources. Retrieved March 4, 2009, from http://www.pge.com/microsite/pge_dgz/more/alternative.html For help creating graphs, try this website: National Center for Education Statistics (n.d.). Create a Graph. Retrieved February 17, 2009, from http://nces.ed.gov/nceskids/CreateAGraph/default.aspx I did not use your school fake library……..is to cheap for this project but just go and have try on it….I can fed spoon you. Materials and Equipment Plastic milk jug, 1-gallon Permanent marker Ruler, metric Small nail, 1 inch long Duct tape Tape measure Stepping stool, or bricks or blocks of wood Timer Lab notebook Graph paper Experimental Procedure Note: Your milk jug will serve as a model of a reservoir, with one side of the milk jug acting as a model of a dam wall. Preparing Your Milk Jug Rinse the milk jug out so that it's clean. Throw away the jug cap. With the ruler and the permanent marker, make three marks on the wall of the milk jug that is opposite the handle: Make the first mark in the center of the wall, 3.5 inches up from the bottom. Make the second mark 1 inch to the left of the center mark and 1 inch up from the bottom. Make the third mark 1 inch to the right of the center mark and 6 inches up from the bottom. Press the nail into each mark until it pokes through the wall of the milk jug. Once the nail pokes through, rotate it in a circle a few times, to help make a well-defined, circular hole. Be careful with the sharp nail. Cover the three diagonal holes with a strip of duct tape, as shown in Figure 4, pressing on the tape gently to seal the holes. Take your milk jugs to the area where you plan to do the testing, such as a bathtub, a garage, or an outdoor area where it is safe to experiment with slow-flowing water. Ask your parents where to test if you are unsure about where a good area might be. Testing Your Milk Jug Write down in your lab notebook/Journal what you think will happen when you fill the milk jug up with water and remove the piece of duct tape. Do you think any of the streams from the holes will be longer than the others? What do you think will happen to the length of the streams over time? Make three data tables in your lab notebook, like the one shown below. Stream Lengths Data Table 1 Time (min)Lowest Hole Stream Length (cm)Middle Hole Stream Length (cm) Highest Hole Stream Length (cm)Reservoir Height (cm) 0 1 2 3 Place your milk jug in the test area on top of the stepping stool, stacked bricks, or blocks. Extend a tape measure from the base of the milk jug out about 18 inches and lock it so that it stays in place in front of the milk jug, as shown in Figure 5. Figure 1 Figure 1. THABANG MODIBA PHOTOGRAPHING NOKIA 1680 Fill the milk jug up to the top with tap water. Get your timer ready and reset it to zero. Remove the duct tape from the milk jug and immediately start the timer. This will be your starting time (time = 0 min). Measure and write down the length of each water stream in your data table. Then immediately, with the ruler, measure and record the height of the reservoir (from the bottom of the milk jug to the surface of the water), and record your measurement in the data table. Repeat step 8 each minute, until the level of water in the milk jug reaches the level of the lowest hole. Repeat steps 5–9 two more times for your two other data tables. Analyzing Your Data Table Make three line graphs (one for each data table) that show time (in minutes) on the x-axis and stream length (in cm) on the y-axis for all the holes. You can make the line graph by hand or use a website like Create a Graph to make the graph on the computer and print it. Go to your data table and calculate the difference between the reservoir height and the hole height for each hole when the stream length went to zero. Is this difference the same for all the holes? Looking at your line graphs, do the shapes of the line graphs look the same for all three trials? Which hole produced the longest stream length? Did this hole produce the longest stream length over the entire test time? Which hole produced the shortest stream length? Did this hole produce the shortest stream length over the entire test time? Based on your results do you think the water pressure on a dam wall is greatest at the bottom of a dam, the middle, or near the top of a dam? If you were building a dam, where would you make the dam the strongest? Where would you place the penstock? At which hole depth do you think the most electricity can be produced? Based on the results of your experiment, can you predict what would happen if you made a horizontal row of holes, all at the same height, in the dam wall? Would the stream lengths all be the same? Give it a try and see! Variations Investigate how hole size affects stream flow for a given hole height. Develop a way to calculate the peak water flow rate out of each hole. (The Bibliography above will give you hints on how to do this with the Bernoulli equation.) Assume an efficiency of 0.9 (common for today's modern power plants), and calculate the power that can be produced with each stream, using Equation 1 in the Introduction. CAN YOU NOW SEE MY SECRET WHEN I AM AT HOME? GUYZ YOU CAN PUT YOU OWN IDEA ON THIS PROJECT FOR MORE HELP ON THIS CONTACT A SO CALLED ORIGINAL THINKER”THABANG MODIBA” CELL; 076 178 1245 EMAIL; T.M.MODIBA@VODAMAIL.CO.ZA FACEBOOK; THABANG MODIBA MXIT; THABANG”HIP2B2 BA” ON 076 178 1245 THIS IS HOT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! HAVE FUN JOO!! You don’t have to be genius in science but hard worker