Science Day 2014: Alternative Sources of Energy “Expand students’ minds though applied science” 4 Parts 1. 2. 3. 4. •
Wind Energy Solar Energy Biomass Energy Hydroelectric Energy Everything the student builds is theirs to keep and take home.
Philosophy: a child’s education is a colaboration between the parents, teachers and student. Science projects are a great way to involve parents and this is encouraged. Have fun learning together.
When: Wednesday, April 30th, 2014. Schedule: 8:45 to 9:00 Arrive and registration 9:00 to 9:05 Science Day Introduction 9:05 to 10:30 Wind Energy: test Wind Power 10:30 to 11:15 set up Solar Energy : set up. 11:15 to 12:00 Solar Energy: test for fastest car 12:00 to 12:45 Lunch break heated with Biomass Energy
12:45 to 2:00 Hydroelectric Energy: build hydroelectric power station 2:00 to 2:30 Hydroelectric Energy: test most powerful hydroelectric power station 2:30 to 3:00 Prizes* Prizes (from Zerotoys.com) presented at 2:30 pm.
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Table of Contents Location/Map ……………………………………………………………………………………
p. 3
Introduction ………………………………………………………………………………………
p. 4
1. Wind Energy …………………………………………………………………………………..
p. 6
p. 7
Experiment 1: Wind Turbine ……………………………………………………
2. Solar Energy …………………………………………………………………………………..
p. 11
Experiment 2: Solar Car …………………………………………………………..
p. 13
3. Biomass Energy …………………………………………………………………………......
p. 14
Experiment 3: Lunch ……………………………………………………………….
p. 14
4. Hydroelectric Energy ……………………………………………………………………..
p. 15
p. 17
Experiment 4: Design, Build and Test a Pelton Wheel ……………….
Just a joke. Here we expect lots of parent help.
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Location: Fraser Valley Distance Education School 46361 Yale Road East Chilliwack, B.C. V2P 2P8
Parking
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Introduction. Your alarm goes off. You turn on the lights, make toast and throw a load of laundry in the washing machine. At school and work, lights and equipment is turned on. When you go home, the stove and TV are turned on and you throw your load of laundry in the drier. During the night while you sleep, your cell phone is charging, the refrigerator is keeping food cold, the furnace is warming the home and all those little LEDs and circuitry running on chargers, TVs, alarms and computers are drawing energy. You take it for granted. Our electrical provider, BC Hydro responds to the these constant and varying electrical loads 24 hours a day. In the cold of winter, many people use electrical space heaters and in the summer, many people use air conditioners. BC Hydro has to balance these loads with their electrical capacity which peaks in the spring when the winter snow melts and wanes in the summer-‐to-‐fall dry season. BC, prior to 1993 always had excess energy, so that even during the lowest water flows, we could produce enough energy. Since 1993, growth in BC electrical energy consumption has exceeded our growth in electrical energy production. During the spring melt, we export electricity (unfortunately there is market glut then so prices are lower) and import electricity other times of the year (when prices are higher). BC’s consumption has increased to the point now, we are a net importer of electricity. Most of this imported energy comes from Alberta. More than 90% of Alberta’s electrity is generated from fossil fuels, the vast majority of which is coal. The result: basically every new electrical load, including LED TVs, heat pumps, and electric cars, is being powered by coal to some degree. Conclusion: BC needs to increase production of electricity from renewable and clean sources of energy. We will explore some of these.
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All the apparatuses you build and use are yours to keep. This would be the wind generator, solar car, and pelton wheel.
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1. Wind Energy Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electrical power, windmills for mechanical power, windpumps for water pumping or drainage, and sails to propel ships. Large wind farms consist of hundreds of individual wind turbines which are connected to the electric power transmission network. In BC there two large commercial wind farms: Bear Mountain near Dawson Creek and Dokie Ridge west of Fort St. John. Wind power, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation and uses little land. The effects on the environment are generally less problematic than those from other power sources. In British Columbia, because of mountainous and often remote conditions, the levelized cost for most sites is 9¢ to 15¢ per kWh. As of 2011, Denmark is generating more than a quarter of its electricity from wind. BC is currently capable of producing 2% of its electricity from wind.
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Experiment 1: Wind Turbine Purpose: design, build and test a wind turbine. You will have to optimize power by varying diameter of rotor, size and shape of blades and blade pitch. *You build this at home with materials supplies in a kit. Materials provided: plywood base
hub
tower (long dowel)
blade dowels
generator
flat wood for blades
nacelle (generator housing)
glue, sandpaper
*Inspect the nacelle inside and out so you are familiar with all the holes.. Materials not provided: scissors
nacelle
blades
base
knife tower
saw
blade dowels
clamp or clothes pin paint
hub
paint brush tape
generator
zap strap
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Procedure: make sure you only complete this in the presence of a parent or guardian and be careful with any sharp tools. 1. Gently feed the wires through the large hole in the nacelle so they feed out the smallest hole in the bottom.
2. Pull the wires through until the generator is a few cm from the large hole. 3. Carefully press generator all the way until it is seated. nacelle on flipped on side
bottom view of nazelle
4. Add a little glue in the ½” hole in the bottom of the nazelle for the tower. Insert the tower into the hole 5. Add a little glue in the hole in the base. Insert the bottom end of the tower in the base. Rotate the nacelle so it points forward.
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6. Build blade-‐spar assemblies. You can choose either to have 2, 3, 4 or 6. Shape the blades and glue them to the dowel spars. Glue blades to flat part of spar. Use clothespins or books to press dowel and blade together for glueing. Things to keep in mind: • blades need to identical = same length, weight and shape • blade edge should be sharp to “cut the air” so use sand paper for this. • think of an airplane: the more you emulate (fancy word for “copy”) the shape of a wing (curved top and rounded-‐tapered edges, the more efficient your blades will be. • a smooth surface with high gloss paint reduces aerodynamic drag
7. Mount completed blade-‐spar assemblies to hub. Make sure all blades-‐spar assemblies are identical before. Loosen of the screw in the middle of hub by turning the knurled knob. Pull the two halves of the hub apart. Insert the blade dowels. It is easiest if you do this on the table
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pitch The dowel is a friction fit on the hub. Make sure each blade is tilted (this is called pitch) the same angle. If it is too flat you will get little torque (force to spin hub) and it is too angled, the hub will not turn fast. On modern ships, airplanes and wind turbines, they variable pitch on their propellors. The pitch is steeper when the ships and planes are accelerating to cruising speed. As they approach cruising speed the pitch decreases allowing for the increased velocity of water or air.
Test: First spin the blades by hand so check for balance. Remove a small amount of wood from the heavy side. Test wind turbine tests at home, either outside in the wind or in front of a powerful fan. If there is a wobble or vibration, make adjustments. Observations: on Science Day, we will place your wind turbine in front of a large fan and place an electrical load with a multimeter. The wind turbines will be rated by electrical energy output and attention to detail in engineered construction.
Points: power ranking (1st = 10 points, 2nd = 9, 3rd= 8, etc.) …………...… construction quality (blade symmetry, blade shape, smoothness, paint, wiring, attention to detail, etc.) ………………
/10 /10
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2. Solar Energy: is harnessed two ways, as radiant heat and photovoltaics. Radiant Heat: We are more accustomed to radiant heat as that is what you feel on your skin on a warm, sunny day. Solar radiation in when short wave radiation from the Sun imparts its energy onto a non-‐reflective, dark surface. Anyone who has attempted to walk barefoot on black pavement on a hot summer day can attest to the immense heat potential.
Relatively inexpensive to build, is basically a flat box with pipe painted black covered by an old patio door glass. A pump then circulates the heat water to a heat exchanger on the hot water tank or a large insulated storage tank.
Though not common in Canada, except for the odd backyard pool, 90% of the homes in Cyprus and Israel heat their water and homes this way.
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Photovoltaics is when the short wave radiation from the Sun is absorbed by a semi-‐ conductors, made of impure silicon, which in turn knocks electrons loose. This movement of the electrons is electricity. From 1954 when it started and used extensively in the space program in the 1960’s and 1970’s, it common on low power consumers such as calculators and yard lights. The cost of the silicon photovoltaic panels (approximately $1000/watt), battery storage and conversion to AC current (type of current your home) with an inverter prevents wide spread use, except with large government subsidization.
How does photovoltaics work? Tiny sub-‐atomic particles from sun called photons break up the negative-‐positive pairs. The electrons (negative particles) move in to fill the holes (positive particles) creating an electric field in the p-‐n junction. Some electrons are knocked out towards the top layer and into metal conductor strips, thus generating electricity.
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Experiment 2: Solar Car Car number: ______________ Purpose: design, build and test a solar reflector. You will have to optimize power by varying the size, shape and reflectivity of a solar reflector. You will position the reflector so that it beams its’ light on the solar panel of a solar car. The more light energy the car receives the faster it goes. It is sort of the same thing when I was your age, I used a pocket mirror to reflect sunlight in my older sister’s face and eyes to torment her. Of course I immediately stopped when she threatened to break my fingers. The solar power on my sister’s face increased her energy levels of inflicting sibling pain. Materials provided: • paper • tape • coloured felt pens • solar car (not this one, this one.) • cardboard • aluminum foil • hot glue gun • glue • scissors Procedure: 1. Get your materials
2. Try your car out and see how fast it moves as is. You want it to be faster. 3. Design the shape of your reflector. Preferably you want a very slight parabolic shape (curve like a satelite dish) but the curve has to be much less since your focal point (solar car solar panel) is going to be much farther away (approx. 3-‐4 meters).
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4. Carefully cut the carboard to the size and shape you want. Use tape to get fasten it together. 5. Cut aluminum foil to size. Remember to keep the shiny side up, glue other side down. Use hot glue to fasten it to the cardboard. Ouch!!! The heat from the hot glue will travel right through the aluminum foil so use an oven mitt to puch down on the foil. 6. Test it. Practice shining sunlight on your solar car to make it go faster. Fine tune your reflector and position for maximum speed. 7. Make this car your own. Use paper board, felt pens and tape to make decals to say this is your car. You will be assigned a number for your car.
Points: race ranking (1st = 10 points, 2nd = 9 points, etc.) …………………….….. solar reflector construction quality (symmetry, strength, image) ... race car decoration …………………………………………………………………….
/10 /5 /5
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3. Biomass Energy A biofuel is a fuel that contains energy from geologically recent carbon fixation, unlike coal or oil (mllions of years). These fuels are produced from living organisms. Examples of this carbon fixation occur in plants and microalgae. These fuels are made by a biomass conversion (biomass refers to recently living organisms, most often referring to plants or plant-‐derived materials). This biomass can be converted to convenient energy containing substances in three different ways: thermal conversion, chemical conversion, and biochemical conversion.
Fuel pellets from wood (logs, sawdust, chip), paper, cardboard and straw.
Part of our lunch on Science Day will be cooked with biofuel. Experiment 3: Eat
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4. Hydroelectric Energy: The use of water for energy has been used for centuries , first exployed by the Romans to remove water from flooding mines.
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Overtime the shape of the water wheel improved. The vanes on the water wheel became spoon-‐shaped known as the Knight Wheel.
Lester Pelton working as a millwright and carpenter in the Californai gold fields (1870s) increased the efficiency more by splitting the spoon in two to create the Pelton Wheel. A decade later a generator was added and hydroelectric power was born.
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Experiment 4: Design and Build Pelton Wheel Purpose: design, build and test a pelton wheel for hydroelectric generation. You will have to optimize power by varying diameter of pelton wheel, size/length and number of blades. Materials provided for build: axle
pelton wheel mount frame
spoons for buckets
utility knife
wheel for one ½ of shaft coupler
cutting board
hot glue gun
side cutters
hot glue sticks Materials provided for testing: water tank
drills and drill bits
pump and nozzle
multimeter and electrical load
generator and other ½ of shaft coupler
splash shield
Procedure: 1. Decide number of buckets your pelton wheel will have (ie.e 3, 4, 6, etc.) Centre the cork on the marking guide on the template. Then mark off equally spaced lines around the circumference of your cork.
Turbine marking guide
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2. Place the cork wide-‐end down on a cutting board. Use the utility knife to cut shallow slits on the lines into the cork where the spoons will be inserted. USE CAUTION! 3. Obtain the required number of plastic spooons. Using side cutters, cut the spoon handles leaving about a 1 cm stem on the bowl of the spoon. 4. Be sure your glue gun is warmed up and that you have a glue stick or two handy. 5. Insert the first spoon into the cork slit. Push the stem of the spoon to a depth of 1 cm. 6. Repeat step 5 with the remaining spoons. Adjust the angle and depth of the spoons so they are evenly spaced and all
project from the cork at the same angle. 7. Glue each spoon into place. Best results are if you temporarily remove a spoon fill the slit with glue and quickly re-‐ insert it to its original position. When all the spoons are glued in place, gob glue around the base of each spoon for extra measure. 8. Press the dowel shaft (pointy end) through the hole in the centre of the cork. Slide the dowel so about ½ the dowel protrudes on either side of the cork.
Complete a test run. Position your pelton wheel in the turbine housing. Make sure it spins freely. Engage generator on coupling. Close valve from pump. Turn on pump. Slowly open the valve and ensure water spray is centred on the middle of the spoon bowls for maximum power. The brighter the bulb (and the greater the voltage), the more power it is producing. Points: power ranking (1st = 10 points, 2nd = 9, 3rd= 8, etc.) …………...… construction quality (wheel symmetry, attention to detail, etc.) ..
/10 /10
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