Tracking the Sun Solar Tracker A solar tracker

Tracking the Sun

Solar Tracker • A solar tracker is device that orients a solar panel toward the sun. • Solar panel trackers are used to reduce the angle between the incoming light and a photovoltaic panel. • This increases the amount of energy produced 2 http: //en. wikipedia. org/wiki/Solar_tracker

Trackers are used on most large solar farms http: //www. justmeans. com/editorial/wp-content/uploads/2010/02/mil_solar_farm_nellis_afb_lg. jpg 3

Power Lost Due to Panel not Facing the Sun • 15° 3. 4% power lost • 30° 13. 4% power lost • 45° 30% power lost 4 http: //en. wikipedia. org/wiki/Solar_tracker

Discussion on sun position http: //www. byexample. com/library/illustrations/seasonal_sun/illustration_sun. jpg 5

Reasons for the Seasons 6

Earth Rotation http: //astro. unl. edu/naap/motion 1/animations/seasons_ecliptic. html 7

Direct versus Indirect 8

Direct versus Indirect 9

Direct versus Indirect 10

• What causes seasons? • Why do we have “shorter” days during the winter and “longer” days during the summer? • http: //astro. unl. edu/naap/motion 1/animations/s easons_ecliptic. html (Shows Earth’s rotation and orbit throughout the year)

Solar Tracker Design Challenge Indiana Solar Power Company needs your help. They are interested in using solar panels to obtain as much energy as they can from the sun. In order to maximize the amount of solar energy collected by the solar panels, the panels must be positioned such that they face the sun at all times of the day and during all seasons. The company is asking you to develop a solar panel system that can be easily moved to track the sun so that the panel can collect as much solar energy as possible. It should be able to move horizontally to track the sun throughout the day and vertically to capture the angle of the sun as the seasons change. The solar panel does not have to move on its own (motors are not provided). However, you can assume that the final product would use a motor or other system to move the solar panel.

Problem Scoping Identifying the problem • What is the problem? – Indiana Solar Power Company is trying to find a way to obtain as much energy as they can from the sun. • What is the goal? – Design a solar panel system that is able to track the sun so that the panel can collect as much solar energy as possible. • Who is the client? – Indiana Solar Power Company • Who is the end user? – Anyone who uses electricity

Problem Scoping Identifying the problem • What are the design criteria (desired features)? – The solar panel should be able to move horizontally to track the sun through the day. – The solar panel should also be able to be moved vertically to capture the angle of the sun as seasons change. – The solar panel does NOT have to move on its own (motors are not provided). However, students can assume that a product would use a motor or other system to move the solar panel. • What are the design constraints? – Materials provided

Components used by Engineers Ball Bearings http: //static. ddmcdn. com/gif/how-to-maintain-a-skateboard-1. jpg http: //skateboarding-tricks-01. webs. com/skateboarding-tricks. jpg

Components used by Engineers Ball Bearings • Things roll better than they slide. • Rolling friction has less resistance that sliding friction. • These balls or rollers “bear” the load.

Ball Bearings • Most common type • Very small contact point

19 http: //www. mdguidelines. com/images/Illustrations/hip_repl. jpg

Components used by Engineers Four Bar Linkage �Consists of 4 bars connected to form a loop. �Can be designed to make a wide variety of movements. 20

Examples of Mechanisms Lift platform Front loader Can crusher Hany A. Sherif, Qassim University http: //www. docstoc. com/docs/74748705/introduction-College-of-Engineering-Qassim-University# 21

Examples of Mechanisms Lift platform Microwave carrier to assist people on wheelchair Hany A. Sherif, Qassim University http: //www. docstoc. com/docs/74748705/introduction-College-of-Engineering-Qassim-University# 22

Idea Generation Individual Plan • Do you have enough information? • What questions do you still have? • In your design notebook, label “Individual Design” on one page • Draw a sketch of your design → Include labels, perspective, scale

Materials Material Cost Marbles $2 Each Plastic Cups $10 Each Vinyl Corner Bead Pieces $5 Each Bendy Straws $15 Each Duct Tape Free Round Plastic Plates $10 Each Golf Balls $4 Clay $20 (As much as needed) Brass Paper Brads $1 Each Small Solar Panel $100

Idea Generation Team Design • In your design notebook, label “Team Design” on next page. • Share your plan with members of your design team. • Agree on one design. Draw a sketch of your team design and create a list of materials you will need (and cost).

Solution Production and Performance Construct and Test • You will have 20 minutes to construct • Keep in mind: – You must follow your team design – Use only the materials provided – Note any modifications you wish to make to your design

Solution Production and Performance Construct and Test • How are we going to test our designs? Test Conditions • Attach multi-meter to solar panel. • Mount flashlight on tripod. • Record change in voltage output as move solar panel.

Data Collection Team # Multimeter Reading Summer Angle Multimeter Reading Winter Angle Cost 1 90 25 $145 2 90 20 $132 3 100 60 $168 4 90 30 $150 5 100 30 $167 6 100 65 $174 7 100 60 $134 8 100 40 $117 9 100 50 $213 10 100 50 $129

Communication Share Results • What were your results? • Did your team’s design meet the client’s needs? • In what ways did your team use what you know about the angle of the sun and direct/indirect rays to inform your design?

Optimization Improve and Re-design • In what ways could you improve your design? • What is one feature you could re-design? • To what extent could your re-design improve your results?

Student Work

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Cross curricular connections • Mathematics – Estimation – Computation (use of equations) – Cost analysis • Literacy – Writing – Persuasive writing – Narrative writing • Literacy - Reading

Assessment Formative • Review design notebooks • Use an observation checklist to record observations of students’ testing of their predictions of simple circuits Summative • Designs (artifacts) • Review responses to key questions in design notebooks • Rubrics

Real life connection Smartflower POP https: //www. youtube. com/watch? v=Nf. YW 97 GMu. WQ

Contact Info • Heidi Vance, Taylor Middle School hvance@taylor. k 12. in. us • Laura O’Shaughnessey, Lafayette Christian loshaughnessey@lafayettechristian. org Chell Nyquist, SLED project engineer nyquist@purdue. edu