Where Does Energy Come From?
Read page D-78
Activity 68
Title: Photovoltaic Cells
Problem: How can you use solar cells to
produce the most energy possible?
Hypothesis: If _____________, then
____________________________.
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
The largest photovoltaic solar power
plant in the United States is becoming a
reality at Nellis Air Force Base
Roof with photovoltaic cells
http://www.brainpop.com/technology/energytechnology/solarenergy/
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
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.
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.
1. 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.
2. 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.
3. 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.
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