1. Where Does Energy Come From?

2. Read page D-78

3. Activity 68 Title: Photovoltaic Cells
Problem: How can you use solar cells to produce the most energy possible?
Hypothesis: If _____________, then ____________________________.

4. 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

5. Roof with photovoltaic cells
The largest photovoltaic solar power plant in the United States is becoming a reality at Nellis Air Force Base

6. Part A: Making a One-cell Circuit
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

7. Today’s 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.

8. 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 don’t solar cells provide enough electricity to run a house through a full day or a full year? Use evidence from this investigation to explain.

12. 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”
Photovoltaic Cells: Advantages & Disadvantages
Advantages
Disadvantages