Teacher : Carlos Fukunaga / FIU - Florida International University
SOLAR CELLS : NEW HORIZONS
Subject Area(s) Mathematics /Engineering
Associated Unit Renewable Energy Demonstration
Lesson Title Photovoltaic Cells
Header
Image 1
Image file: https://en.wikipedia.org/wiki/Solar_cell
ADA Description: Photo showing a module of a photovoltaic cell
Source/Rights: Copyright © en.wikipedia.org
Caption: Photovoltaic Concept of .Nanotechnology is behind the
Improvements in Photovoltaic cell production.
Grade Level 11 - 12
Time Required 45 minutes
Summary
Solar cells known technically as Photovoltaic Cells (PV) are used to convert photons from
solar rays to electricity. The use of this renewable energy has been emerging rapidly due
to the necessity of use alternative energy resources for massive consumption at worldwide
level. Students will have the opportunity to analyze the chances and benefits of
using solar cells and to lead into a discussion regarding this renewable energy with
engineering applications at greater scale to call for their interest in this area.
Engineering Connection: Like Engineers students will be exposed to :
1. Conversion of energy in different steps: From Electro-chemical energy reaction to create a
light that will illuminate the photovoltaic cell which will be connected to a small fan.
2. Students will analyze the use of renewable energy with different resources.
3. Minds from scholars will start working on the application of this engineering concepts in
areas where resources are not reachable such as far away from cities and where energy is
in demand and in need.
4. Mathematically is the calculation of type of energy needed to produce a certain needed
capacity.
5. Unit Conversions using mathematical basic concepts.
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Engineering Category = (1) Relating science and math concepts to engineering application and
demostration
Keywords
1. Alternating Current (AC), the movement of electric charge periodically reverses
direction. AC is the form of electric power delivered to businesses and residences. The
usual waveform of an AC power circuit is a sine wave.
2. Conductor : Material that has a very high electrical conductivity
3. Current : Flow of electrons
4. Direct Current (DC) is the unidirectional flow of electric charge. Direct current is
produced by sources such as batteries, thermocouples, solar cells. Direct current may
flow in a conductor such as a wire, but can also flow through semiconductors,
insulators, A term formerly used for direct current was galvanic current
5. Electric Current is a flow of electric charge. In electric circuits this charge is often
carried by moving electrons in a wire. It can also be carried by ions in an electrolyte,
or by both ions and electrons such as in a plasma
6. Energy: A property of objects which can be transferred to other objects or converted
into different forms, but cannot be created or destroyed. Energy exists freely in nature.
Some of them exist infinitely (never run out, called renewable), the rest have finite
amounts (they took millions of years to form, and will run out one day, called nonrenewable).
7. Non-renewable Energy: Energy from fossil fuels (coal, crude oil, natural gas) and
uranium. Fossil fuels are mainly made up of Carbon. Probably fossil fuels were
formed over 300 million years ago.
8. Photon: A photon is an elementary particle, the quantum of light and all other forms
of electromagnetic radiation coming from sun for instance.
9. Photovoltaics (PV) is the name of a method of converting solar energy into direct
current electricity using semiconducting materials that exhibit the photovoltaic effect.
Photo means photon and voltaic is voltage
10. Renewable Energy : Any naturally occurring, theoretically inexhaustible source of
energy, as biomass, solar, wind, tidal, wave, and hydroelectric power, that is not
derived from fossil or nuclear fuel
11. Semiconductor : Material that has a moderate electrical conductivity
12. Voltage: Electrical pressure that exists between two points and is capable of
producing a flow of current when a closed circuit is connected between the two points.
Educational Standards (List 2-4)
NGSS Standard (strongly recommended)
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CCSS Standard (strongly recommended)
Mathematics
Domain: ALGEBRA: REASONING WITH EQUATIONS & INEQUALITIES
Cluster 1: Understand solving equations as a process of reasoning and explain the reasoning
Algebra 1 - Major Cluster Algebra 2 - STANDARD CODE
STANDARD
MAFS.912.A-REI.1.1
Explain each step in solving a simple equation as following from the equality of numbers
asserted at the previous step, starting from the assumption that the original equation has
a solution. Construct a viable argument to justify a solution method. Cognitive
Complexity: Level 3: Strategic Thinking & Complex Reasoning
MAFS.912.A-REI.1.2
Solve simple rational and radical equations in one variable, and give examples showing how
extraneous solutions may arise. Cognitive Complexity: Level 3: Strategic Thinking &
Complex Reasoning
Chemical Reactions:
HS-PS1-2. Construct and revise an explanation for the outcome of a simple chemical reaction based on the
outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical
properties
HS-PS1-4. Develop a model to illustrate that the release or absorption of energy from a chemical reaction syst
depends upon the changes in total bond energy
HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are
conserved during a chemical reaction.
Energy
HS-PS3-4. Plan and conduct an investigation to provide evidence that the transfer of thermal energy when two
components of different temperature are combined within a closed system results in a more uniform energy
distribution among the components in the system (second law of thermodynamics).
Pre-Requisite Knowledge
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Student should be familiar with the conversion of units from Celsius (C ) to Fahrenheit ( F)
degrees and vice versa from Fahrenheit (F) to Celsius (C ) applying basic mathematical concepts.
Formulas are as follows:
C=5/9(F−32) and F=(9/5)C+32
Derived from table of Temperature chart as follows:
F - 32
C
--------- = ------180
100
Learning Objectives
After this lesson, students should be able to:
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
Senior Classes :The main objective is to wake up the interest in the engineering field and its
application in the real world: how the things can be moved, created or built up for the benefit of
humanity

Another main objective is to realize the use of renewable energy instead of non-renewable one

Drive the senior students to fulfill the needs of Science students at a higher levels.

Flashing the minds of students with the new technologies.
Introduction / Motivation
What would happen if you are in areas that you do not have access to power or light to cover your needs in
a case of emergency?
What would you do in the middle of a blackout (power outage) for a longer time that you expected,
if you do not have a flashlight handy?
If you were in camping night and you runout of batteries, how do you create light if there is not
even a moon light?
Did you know that you can use salty water to make a light bulb shine? It sounds crazy, but it's true!
This is because salty water is a good conductor of electricity.
Salt molecules are made of sodium ions and chlorine ions. (An ion is an atom that has an electrical
charge because it has either gained or lost an electron.) When you put salt in water, the water
molecules pull the sodium and chlorine ions apart so they are floating freely. These ions are what
carry electricity through water. Watch it work in this project!
Lesson Background & Concepts for Teachers
Process of Electrolysis (Figure 1 below)
The key process of electrolysis is the interchange of atoms and ions by the removal or addition of
electrons from the external circuit. The desired products of electrolysis are often in a different
physical state from the electrolyte and can be removed by some physical processes. For example,
in the electrolysis of brine to produce hydrogen and chlorine, the products are gaseous. These
gaseous products bubble from the electrolyte and are collected.[3]
2 NaCl + 2 H2O → 2 NaOH + H2 + Cl2
A liquid containing mobile ions (electrolyte) is produced by:


Solvation or reaction of an ionic compound with a solvent (such as water) to produce
mobile ions
An ionic compound is fused by heating
An electrical potential is applied across a pair of electrodes immersed in the electrolyte.
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Each electrode attracts ions that are of the opposite charge. Positively charged ions (cations) move
towards the electron-providing (negative) cathode. Negatively charged ions (anions) move
towards the electron-extracting (positive) anode.
In this process electrons are either absorbed or released. Neutral atoms gain or lose electrons and
become charged ions that then pass into the electrolyte. The formation of uncharged atoms from
ions is called discharging. When an ion gains or loses enough electrons to become uncharged
(neutral) atoms, the newly formed atoms separate from the electrolyte. Positive metal ions like
Cu++ deposit onto the cathode in a layer. The terms for this are electroplating electro winning and
electro refining. When an ion gains or loses electrons without becoming neutral, its electronic
charge is altered in the process. In chemistry the loss of electrons is called oxidation while electron
gain is called reduction.
On next process the lightbulb will radiate energy (simulating solar energy) to a photovoltaic cell
(solar panel) that will be connected to a small fan.
How does a Photovoltaic cell work? (Figure 2 below)
A typical silicon PV cell is composed of a thin wafer consisting of an ultra-thin layer of
phosphorus-doped (N-type) silicon on top of a thicker layer of boron-doped (P-type) silicon. An
electrical field is created near the top surface of the cell where these two materials are in contact,
called the P-N junction. When sunlight strikes the surface of a PV cell, this electrical field provides
momentum and direction to light-stimulated electrons, resulting in a flow of current when the solar
cell is connected to an electrical load
Regardless of size, a typical silicon PV cell produces about 0.5 – 0.6 volt DC under open-circuit,
no-load conditions. The current (and power) output of a PV cell depends on its efficiency and size
(surface area), and is proportional to the intensity of sunlight striking the surface of the cell. For
example, under peak sunlight conditions, a typical commercial PV cell with a surface area of 160
cm^2 (~25 in^2) will produce about 2 watts peak power. If the sunlight intensity were 40 percent
of peak, this cell would produce about 0.8 watts.
The U.S. Department of Energy has produced a QuickTime video of how a PV cell works.
Take a look (Downloadable MPEG file).
Images
Figure 1 : Electrolysis
Figure 1 : Electrolysis
Image file:
http://www.chemistryland.com/CHM130FieldLab/Lab11/Lab11.html
ADA Description: The
conductivity of electrolytes is indicated by the
Brightness of the lightbulb
Source/Rights: Copyright © Copyright © en.wikipedia.org
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Figure 2 : Photovoltaic Cell
Figure 2 : Photovoltaic cell
Image file: http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/how_pv_cells_work.htm
ADA Description: A
typical silicon PV cell is composed of a thin wafer consisting of an ultra-thin layer of
phosphorus-doped (N-type) silicon on top of a thicker layer of boron-doped (P-type) silicon. An electrical
field is created near the top surface of the cell where these two materials are in contact, called the P-N
junction. When sunlight strikes the surface of a PV cell, this electrical field provides momentum and
direction
light-stimulated electrons, resulting in a flow of current when the solar cell is connected to an
AssociatedtoActivities
electrical load
Source/Rights: Copyright © Copyright © en.wikipedia.org
Assessment
Pre-Lesson Assessment
Descriptive Title: From energy to energy with renewable resources with an Introduction to
Nanotechnology.
Teacher opens class with an introduction of energy concept, renewable and no-renewable energy, as well
as the offer and demand of energy in real life, flash the student mind with what would happen if these
resources would be running out some day or become scary or result too expensive to get them for different
reasons? Questions to brainstorm minds and get them to be involved in the topic. Teacher explains to
students about the project to be shown on how to get light from salty water and how this light (working as
solar energy) will feed a photovoltaic cell to generate energy and move a little fan. From energy to energy
using renewable resources. Teacher will also explain with an example how to use mathematical formulas
of temperatures converting from Celsius to Fahrenheit degrees and vice versa. A brief introduction of
Nanotechnology and applications with a video.
Post-Introduction Assessment
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Descriptive Title: Renewable Energies Assessment.
Students will take a short assessment of what they learned in class. Teacher will print and pass out to
students the following questions to be answered in class in 20 minutes:
Topic: Using Renewable Energies and Solar Panels. Post Assessment.
Name:______________________________ Period____________Date___________
1) What is the difference between Renewable Energy and Non-renewable energy?
2) List all the Renewable and Non-renewable energies that you know.
3) Convert 22 Celsius degrees into Fahrenheit degrees.
4) Convert 97 Fahrenheit degrees into Celsius degrees
5) How would be the use Ocean water as a resource of energy?
6) Explain how Nanotechnology application in Solar Panels improve the use of Solar Panels at
home?
7) List the different professionals that you think are involved in energy conversion
8) List the different areas of application of Nanotechnology
Lesson Summary Assessment
Descriptive Title: How did you like the topic of Energy?
Teacher will answer all the questions students have and clarify the doubts of the same, highlighting the
importance of new technology application like Nanotechnology especially in Solar Panels to improve the
massive demand and showing the students of Importance and application of Engineering and others
Science fields.
Homework
Descriptive Title: Imagination
Describe in 200 words:
1) How will be the impact of new and improved solar panels in the future?
2) Explain and give example of Nanotechnology in your own words.
References
https://en.wikipedia.org/wiki/Electric_current
https://en.wikipedia.org/wiki/Electrolysis
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http://www.fsec.ucf.edu/en/consumer/solar_electricity/basics/how_pv_cells_work.htm
http://teams.eas.muohio.edu/solarpower/video/solarcell2.mpeg
http://www.chemistryland.com/CHM130FieldLab/Lab11/Lab11.html
https://en.wikipedia.org/wiki/Electrolysis_-_cite_note-Tilley2004-3
https://www.teachengineering.org/browse_standards.php?submitted=true&state=Florida&lowgrade
Contributors
Carlos Fukunaga, Ms. Kerlyn Prada (MDCPS)
Supporting Program
College of Engineering and Computing – Engineering Center / Florida International University.
Acknowledgements
Dr. Masoud Milani (Florida International University), Dr. Arif Sarwat (Florida International
University), Dr. Patrick Roman (Florida International University), Dr. Nezih Pala (Florida
International University) and Ms. Stephany Strange for her continuous kind assistance and support.
Classroom Testing Information
This lesson plan is prepared basically for senior classes in order to interest them in the areas of
Science and Engineering fields at the University/College levels.
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