HOME LIGHTING in DEVELOPING COUNTRIES
TEACHER TUTORIAL
This self-paced tutorial will help prepare you to implement the Home Lighting in
Developing Countries module of the SAGE project. Teacher tutorials are also available
for each of the other three SAGE instructional modules. It’s recommended that students
complete the Introduction to the Core Concepts of Systems Engineering module prior to
the Home Lighting module.
Tutorial Goals:
o To learn about appropriate technology its possible application in
developing countries
o To learn about solar and LED technologies
o To prepare teachers to implement the Home Lighting in Developing
Countries module of the SAGE project
Many of the products and technologies that are of particular interest to today’s students
are electronic. To be technologically literate and informed consumers they should
develop a working knowledge of the basics of electric circuits such as what is needed to
create a circuit, the differences between series and parallel circuits and the application of
Ohm’s law. Photovoltaic power generation and LED lighting are two of today’s rapidly
advancing technologies. Combining these technologies offers the possibility of providing
safe, reliable and affordable lighting for people in developing countries.
Appropriate Technology
Often the technologies needed to improve life in developing countries are much different
than the latest technologies we are accustomed to using. People in developing countries
need affordable and effective solutions to problems that most of us don’t have, such as
access to clean drinking water and safe home lighting An appropriate technology
approach focuses on understanding the needs of the user as an important first step in
developing solutions to significant social and technological problems.
This four-minute video explains appropriate technology and gives examples of its
application in developing countries:
o http://www.youtube.com/watch?v=0UrxP7cXhbA
Key Electricity Concepts
The basic electronic components needed to construct a solar/LED circuit include solar
cells, resistors, capacitors, diodes and LED’s. The interactive web site below is designed
to introduce high school students to important electricity concepts. It’s also good
refresher for teachers.
http://www.ndted.org/EducationResources/HighSchool/Electricity/workwithelectricity.htm
Reflection Questions:
o
What are the fundamental differences between series and parallel circuits?
o
Why is it important for students to understand series, parallel and series-parallel
circuits as they prepare to construct solar/LED lights.
Solar
Solar yard lights are inexpensive and readily available. They can be disassembled by
students and their components can be used as the basis as for constructing solar/LED
prototype projects. Solar yard lights can also be used to teach about reverse engineering.
Reverse engineering is the process of disassembling a product to discover how it’s made,
what it is made from and how it works. You can learn more about reverse engineering
from the Introduction to Core Concepts of Systems Engineering module and teacher
tutorial (http://www.ciese.org/curriculum/seproject/index.html).

Read: How Solar Yard Lights Work
o http://www.howstuffworks.com/solar-light.htm
Reflection:
o How do the major electronic components (solar cell, resistors, LED’s,
diodes and capacitors) work together in the basic circuit needed for a
solar/LED lighting system?
o If you have an opportunity, disassemble a solar yard light. Compare your yard
light yard to the one described in the How Stuff Works article. How are they
similar? How are they different?
LED’s
LED’s are an increasingly important source of lighting for automobiles, traffic signals, and
commercial lighting. Home improvement stores are beginning to sell them for consumer
applications. The online resource, How Stuff Works, has an article that explains how diodes
work, the advantages of LED’s and links to other articles about LED’s and their applications.

http://www.howstuffworks.com/led.htm
LED’s Magazine (http://www.ledsmagazine.com/main) is an online magazine that focuses on
describing innovation within the LED lighting industry. Each issue includes articles, news about
new products and case studies that describe success stories and the challenges of using LED’s for
new applications.
Combining LED and Solar Technologies
Light Up The World Foundation
 http://www.lutw.org/index.html
The Light Up The World Foundation is an international organization whose mission is to
provide renewable and appropriate energy to communities throughout the world that do
not have access to affordable energy. Their web site provides up-to-date information
about their current projects and products. Share this web site with students to help them
understand how their projects have changed lives by allowing families to purchase food
rather than spending money on batteries or candles.
Final Reflection
Think about how you will introduce your students to appropriate technology through an activity
that introduces them to key electricity concepts as well as solar, LED and other contemporary
technololgies.