Where Does Energy Come From?

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Where Does Energy Come From?
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Read page D-78
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Activity 68

• Title Photovoltaic Cells
• Problem How can you use solar cells to produce
  the most energy possible?
• Hypothesis If _____________, then
  ____________________________.

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Background Information Solar photovoltaic cells

• A solar photovoltaic cell absorbs light energy
  from the Sun (or other sources) and transforms it
  directly into electricity.
• Light is composed of photons, or packets of
  energy. When photons strike a solar cell, they
  may be reflected, absorbed, or transmitted
  through.
• Photovoltaic is made of two root words
• photo, meaning light
• voltaic, meaning related to voltage

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Roof with photovoltaic cells
The largest photovoltaic solar power plant in the
United States is becoming a reality at Nellis Air
Force Base
http//www.brainpop.com/technology/energytechnolog
y/solarenergy/
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Procedure Part A Making a One-cell Circuit
1. With your group, set up a circuit that uses
the photovoltaic cell to run the motor, as shown
in the diagram below.

• Use the questions on page D-79 to help you design
  your investigation. Discuss a procedure with your
  group (4-5 people) and how you might gather your
  data. Answer the questions on the bottom of your
  template.
• The procedure should change only one variable at
  a time
• Measurements should be taken consistently
• Minimize human error
• Hint look at your equipment

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Todays Challenge

• Find the best angle to the sun to produce the
  most energy.
• Start with the cell flat on the ground and
  increase the angle in 10 increments.
• Answer the analysis questions as you work.

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Analysis Questions
Answer the analysis questions on the back of
your template. Read the questions first and
gather any information you need to answer them.

• For the solar single-cell setup that made the
  motor spin the fastest
• Sketch and describe the setup, including the
  position of the solar cell relative to the Sun.
• Explain why you think this setup worked the best.
• For the two-cell setup
• Sketch and describe the setup.
• Compare and explain the effect of having two
  solar cells in series to having one.
• In most of the United States, why dont solar
  cells provide enough electricity to run a house
  through a full day or a full year? Use evidence
  from this investigation to explain.

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Homework

• Make a list with explanations of advantages and
  disadvantages of photovoltaic cells (5 to 6 of
  each)
• Fold a sheet of notebook paper in half
• Title it, Photovoltaic Cells Advantages
  Disadvantages