Project based learning through the implementation of solar cooking for sustainable development

JOURNAL OF SCIENCE OF HNUE
Interdisciplinary Science, 2014, Vol. 59, No. 5, pp. 77-84
This paper is available online at

PROJECT-BASED LEARNING THROUGH THE IMPLEMENTATION
OF SOLAR COOKING FOR SUSTAINABLE DEVELOPMENT

Tuong Duy Hai1 , Do Huong Tra2 and Jacques Ginestie1
1

2

EA 4671 ADEF, Aix-Marseille Université, France
Faculty of Physics, Hanoi National University of Education

Abstract. In this article, looks at the teaching methods of a grade 12 project-based
learning (PBL) physics course in solar energy as a part of a sustainable
development (SD) curriculum. It was shown that discussions about solar cooking
and natural resources projects put many important ideas into students’ heads
indicating an effective improvement of PBL and education for SD in schools.
Keywords: PBL, solar cooking, sustainable development, learning activities.

1.

Introduction

Knowledge, skill and attitude are basic components of ability that a student should
strengthen and practice in order to connect learning to practical events in real life and help
students obtain employment and be more productive members of society [1]. Knowledge
is built from teaching curriculums; skills are developed, strengthened and cultivated from
learning activities; and attitude is fundamental for a student to make use of the first two

components when dealing with a problem which they may face in real life.
Instilling a proper attitude in students is a principal target of education for SD a
growing practice in global education and an exciting manner of teaching with practical
subjects related to environmental protection and pollution minimization, encouraging
students to act as a team, tying school activities with daily life, fostering interaction among
students and building ideas about a more sustainable future.

2.
2.1.

Content
Experimental process description

PBL includes the teaching method, student action and way of learning, performance
progress, time and duration, teaching facilities and subject composition. To carry out this
Received December 25, 2013. Accepted May 30, 2014.
Contact Do Huong Tra, e-mail address:

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Tuong Duy Hai, Do Huong Tra and Jacques Ginestie

research, it is necessary to discover how students learn and, on the basis of this data,
determine a teaching process suitable for the existing conditions in the schools. With this
in mind, we looked at the process of teaching the subject of solar energy as a part of the
high school Physics curriculum within framework of education for SD in order to learn
how students study in such a teaching framework [2].
This PBL project started by showing edited films about solar energy and practical
ways of making use of solar energy and combining this with a VTV the solar cookers

project in Da Nang city as reported on VTV1. Class discussions then took place with a
teachers acting as observers. Discussions took place about solar cookers and potential for
solar cooking in the local community [3].
The student groups were then given the task of designing and making a solar
cooker. Three weeks later a project presentation and report was held and both teachers and
students assessed their learning progress and project products. This project is to be used by
Physics teachers to create an objective, true database for future analysis. The entire project
process was video and audio recorded, entered into project logbooks, and interviews were
done at the end of the project. The project involved 109 12th grade students in three
schools: Đội Cấn, Đại Cường and Thanh Oai B (DOC, DAC and TOB). The experiment
took place in September, 2012.

2.2.

Analysis of results
Table 1. List of materials used by the project groups

Group
DOC1 DOC3 DOC4 TOB1 TOB2 TOB3 DAC1 DAC2 DAC3 DAC5
Carton
X
X
X
X
X
X
X
X
X
Wood frame

X
X
X
Sheet metal
X
X
Soft box
X
X
X
X
Glass
X
X
X
X
X
X
X
Plastic board
X
X
Rice husk
X
X
Silver paper
X
X
X
X

X
X
X
X
Mirror
X
Steel wire
X
X
Iron bar
X
X
Wood bar
X
X
Wastepaper
X
Bamboo
X
frame
Beer can
X
X
Black paint
X
X
X
Newspaper
X

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Project-based learning through the implementation of solar cooking for...

Resulting from this project was 10 solar cookers that could sterilize foodstuffs using
the Pasteur method [4] on sunny days with a temperature of between 60◦ C and 78◦ C.
After analyzing the products, documents and video and audio data, ways to improve
implementation of the project could be ascertained and will influence our suggestions to
improve PBL in education for SD in school.
a. Materials used by students to make a solar cooker
Type of materials to be used were discussed by the students with their concern being
to make use of available materials such as cartons, fruit containers, instant noodle boxes
and easy-to-find materials like glass, chopsticks, bamboo, wood and sheet metal, flower
wrapping, glue, candles, 502 glue and clear plastic which meet the criteria of cheap„ easy
to obtain and easy to work with. For the most part they made use of household waste
products such as rice husk, beer cans, newspaper and wastepaper.
The students’ biggest concern regarding materials to make a solar cooker was cost,
and this was because they themselves bore the cost. For this reason their final products
were made very cheaply, at more than VND 10,000 VND but less than VND 100,000.
Such prices are acceptable for a group of 3-5 students who share those expenses.
Cartoon, silver paper and glass were the most commonly used. Silver paper was
replaced by some with glass plate or beer cans that were flattened to make a reflection
plane. Some replaced the glass with transparent plastic when attempting to create a
greenhouse effect. The cartoon could be replaced with a wood frame, bamboo frame,
or sheet-metal frame with wastepaper, rice husk inside or air space serving as thermal
insulation. Students considered using materials that were environmentally friendly.
b. Time and place of group discussion and product fabrication
Students were given three months to complete the project. This was quite a long
time for a group of three to five 12th grade students to plan and make a solar cooker but

during this time they were busy with their other subjects and chores. Some students were
enrolled in private lessons elsewhere and the group members were away from school at
different times which did affect progress and the quality of the final project. The group
arranged to meet on Sunday, in the evening or at times there were no classes. Evening
meetings were rare because their homes are very far apart. They had to make use of their
free time to organize their individual activities with the project.
Each person sought materials and kept it at home. They met at home of their team
leader or a member that lived near their school when making their product.
Table 2. Place of team meeting
Place
Home
School

DOC1 DOC3 DOC4 TOB1 TOB2 TOB3 DAC1 DAC2 DAC3 DAC5
X
X
X
X
X
X
X
X
X
X
X
X
X
X

c. Mobilize supports for the project

Students asked many people for assistance in getting information and making their
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Tuong Duy Hai, Do Huong Tra and Jacques Ginestie

product. The data shows that the Physics teacher was the greatest help to the students,
followed by workers who help them to finish the most difficult parts of their product by
doing things such as cutting the glass and assembling the wood or sheet-metal frame.
Generally their relatives helped them put together a bamboo frame.
Cell phones were very useful to the students as they sought information. Via a cell
phone Internet connection, they could find images of solar cookers and try to copy one of
them.
Table 3. Who the students ask for help to perform their project
Student
helpers
Physics
teacher
Relatives
Professional
worker

DOC1 DOC3 DOC4 TOB1 TOB2 TOB3 DAC1 DAC2 DAC3 DAC5
X

X

X

X

X

X

X
X

X

X

The table above shows that the project involved teachers, parents, relatives and
skilled workers.
d. Student activities within a group
Each student was involved in various activities in the course of the project. There
was always one student who was the leader and bore the main responsibility for the
product. The leader had to link the various group members, organize group meetings,
allocate duties and attempt to speed up the work of each member. When their product was
defective or unfinished, they had to improve or complete it. The leader played a key role
in the project presentation and answered the project-related questions for his group.
Table 4. Roles of group members
Group has
DOC1 DOC3 DOC4 TOB1 TOB2 TOB3 DAC1 DAC2 DAC3 DAC5
one member
with the most
X
X
X
X

X
X
X
X
contributions
every member
X
X
with the same
contributions

e. Student knowledge in the discussion
In the discussions, students freely expressed their ideas and opinions. Behind
the students’ ideas and opinions, we found the students to be most knowledgeable in
the areas of economy, sociology and the environment; their Physics-related knowledge,
(energy, science and technology) was minimal. Most of the students took an interest in
the environmental aspect of the solar cooker, followed by cost savings and the health of
the cooker users. Hence, SD education is occurring when the students mention backbone
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Project-based learning through the implementation of solar cooking for...

of this education method rather than knowledge from the curriculums they learn in the
school.
f. The attitude of the students

Diagram 1. Fields of knowledge to be applied
by the students in their discussion about solar cooker
By observing the students during their discussions and analyzing the study

sheets and project documents, we found that some students did not take the project
seriously, could not focus on this area of study and indeed even disregarded the study.
When presenting the final project outcome, students sometimes answered a question by
drawing irrelevant pictures, and recorded project documentation differed from the actual
performance of the students. During the interview, we discovered that students filled
in their documents before or after the project implementation and did not update them
regularly.

Figure 1. Picture of students
When rapid-fire or difficult questions were asked of the students, they seemed to
answer perfunctorily in order to avoid actually answering the questions. For this reason
many of their answers were illogical and inconsistent.

Diagram 2. Students joke around and don’t concentrate on learning
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Tuong Duy Hai, Do Huong Tra and Jacques Ginestie

When carrying out the project, the students were interested only in the hands-on
activity in the project, and not project documentation project organization, understanding
the nature of the product that they are to make or understanding the operating mechanism
of the product. Among other inadequacies, the students lacked teamwork and collective
skills.
g. Way of suggesting an idea in the discussion
Before a discussion took place, we gave the students study sheets and asked them
to write what they thought about the project. Comparing what the students wrote with
what they said the results were similar despite a little difference in quantity and content as
per the student’s level, gender and school. Ideas and opinions of the students from project
schools are characterized by:

- The first student to speak reads from his study sheet but does address a number of
ideas;
- The second student to speak also read his study sheet but omitted any ideas that
were similar to the first student’s; he gave only information that differed from that of the
first student;
- The third student to speak and those following usually spoke of something that is
less similar to the previous students but which is ideas inherited from the prior students
and less related to what they had prepared on their study sheet;
- Sometimes the students addressed just one or two ideas, followed by a burst of
ideas;
- The last speaker is always spoke least and closed the discussion.
Despite a difference in student level, gender and school, there was little difference in
the number and content of their ideas. Discussions tended to hide the difference between
the good and the poor students, enabling the students to feel that they are on an equal
level.

Diagram 3. Structure of ideas which are addressed by the students in the discussion
Each moss-green dot symbolizes an idea to be addressed by a student, each row
refers to a student’s speech and each column indicates a discussion. It can be seen that
apart from column 4, the last speaker usually presents one idea.
It is seen that teachers and experts who want to deepen the discussion process
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Project-based learning through the implementation of solar cooking for...

should make suggestions or provide documentation at the knot time to enrich the
discussion. If this is not done, the discussion may remain at a standstill as they run out of
ideas.
h. Product making by the students

After looking at the products and interviewing the students, we compared each
group’s products from the same school, different schools and within the sample. It was
seen that the student’s copy from each other or copy the sample provided. For example,
they made a concave inside the cooker, paint the exterior black, covered the body of
the cooker with newspaper for thermal insulation, punched a hole in the glass plate
and perhaps improved the mirror rotating system. This shows that the students had no
knowledge of the products they made. A solar cooker that is painted black will not work.
They should paint the pot that is put into the cooker so that it absorbs as much heat as
possible. To get the greenhouse effect, a closed glass cage must be made to reduce thermal
energy and heat the pot in the solar cooker, however, the students punched a hole in the
center of the glass plate which allows dissipation of the heat into the environment and
reduces the effectiveness of the cooker. The students improved the mirror rotating system
by appending many large and long reflecting plates on the cooker wall but these plates
prevented the sunlight from reaching the cooker.
Sadly, their unquestioning imitation and haphazard improvement had an adverse
effect and reduced the effectiveness of the study itself.

Figure 2. Several improvements on the student group’s products
It is possible that if that these students were to work with experts and if they had
scientific documents related to the project product provided to them, they might tend to
copy less and they might get creative because they might then thoroughly understand the
operational principles of their products.

3.

Conclusion

Education of the students is according to school timetable, private tuition and
project budget. Project outcomes have no impact on the study results of the students, hence
the unserious attitude of the students. The students enjoy making the product but discount

organizing for effective study. They attach too much importance to the appearance of the
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Tuong Duy Hai, Do Huong Tra and Jacques Ginestie

product rather than coming to understand the operational principles in order to improve
their products. The students took the simplest path which is to copy without significant
creativity.
The proposed learning process meets the requirements on education for SD in that
it made film clips on solar energy and cookers for the students. Their understanding of
solar cookers and how they can help meet economic, social and environmental needs have
changed for the better.
REFERENCES
[1] UNESCO, 2009. Report of Education for Sustainable Development. Conference,
Boon City, Federal Republic of Germany.
[2] Tuong Duy Hai and Do Huong Tra, 2010. Education for sustainable development
through project-based learning by integrating solar cooker research projects into
Physics curriculum. Education Magazine, no. 241.
[3] Tuong Duy Hai, Jacques Ginestié, Do Huong Tra, 2012. Quelques éléments de
réflexion sur des stratégies de projet d’élèves vietnamiens dans le cadre d’une
éducation au développement durable. JIES International Conference, Chamonix,
Republic of France.
[4] Chillet, 2012. La pasteurisation, in Opérations unitaires en génie biologique. Scérén.

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