After completing this project, students will be able to:

• design and build a working solar oven;
• use the oven to heat food;
• measure specific heat;
• measure temperature in different temperature scales;
• explore changes of state;
• use computers for information exchange;
• use measurement devices with accuracy;
• research solar energy via the Internet and the library; and
• debate the issues surrounding the use of solar energy vs. fossil fuels.

We have been learning about energy and heat and discussing a variety of uses and sources of energy. One of the problems we have identified is the consumption of fossil fuels and the need for alternative sources of energy. One of these sources is solar energy. Your assignment is to construct your own solar oven employing the concepts related to energy we have covered in class. You will work in groups of three to four students.

The following elements must be included in your project:

1. A list of materials needed to construct your oven and an explanation for your choices.
2. A design or "blueprint" of how the oven will be constructed. The plan should include a written description and a graphic illustration. The description should discuss environmental requirements for optimal operation of the oven, i.e., lighting, temperature, etc.
3. A written report.
4. An oral presentation.

Activities that you will perform following the construction of your oven are listed below:

1. Melt cheddar cheese on nachos.
2. Use thermometers of different scales.
3. Measure and record the temperature within the oven over time.
4. Measure the rate at which an ice cube melts.
5. Calculate the specific heat of water.
6. Compare the effect of colors on absorption of heat.
7. Compare heat absorption among different types of metal.

The written group report should include the items listed below:

1. A discussion of the problems encountered during construction and operation, how the problems were resolved and changes you would make for future construction.
2. Observations, measurements, calculations, results and conclusions of experiments. Data must also be represented using graphs.

An individual written essay should address the questions listed below. Other questions will be part of a class discussion.

1. In which geographical areas would a solar oven work best and why?
2. How do conventional ovens work? What are the advantages and disadvantages of these ovens? How do microwave ovens work? What are their advantages and disadvantages? What are the advantages and disadvantages of solar ovens? Which do you think is best and why?
3. Are there any other cooking methods you would like to compare?
4. Why aren’t solar ovens used on a wider scale in the U.S.? Do you think this will change in the future? Why? Are there other areas in the world where their use is more common or could be in the future?

Each group will deliver a presentation to the rest of the class. Each group member must speak. Presentations will be limited to a discussion of the construction and operation of the oven and results of experiments. Total presentation time should be 10 minutes.

Today your groups will decide on a list of materials and a design plan and submit them at the end of this class period. Materials and design plans will be reviewed before you begin construction.

During the two weeks you are working with your ovens, you will wok on the individual research questions. One class period will be provided to work in the library. These written reports will be due the day following group presentations.

Summary of Events:

Day 1: List of materials and design plan.

Day 2: Revisions and final plan due.

Day 3: Construction of ovens.

Days 4-7: Observations, experiments and compilation of group report.

Day 8: Research in library.

Days 9-10: Group presentations.

Day 11: Individual reports due.

Sample Performance Assessment

Materials list (10 pts.)

______Materials are well suited to the project (5)
______Choice of materials is supported by scientific reasoning (5)

Design plan (20 pts.)

______Written description (10)
______Contains enough detail so that instructions can be followed by others (5)
______Evidences of accurate scientific reasoning (5)

Graphic illustration (10 pts.)

______Includes illustration of all parts of design (5)
______Is neat (5)

Quality of the solar oven (30 pts.)

______Oven is sturdy (10)
______Construction accurately corresponds to design plan (10)
______Oven is operable (10)

Written Report, group (30 pts.)

______Content (10)
______Discussion of problems of construction and operation (5)
______Laboratory data is accurate and complete (5)
______Writing is organized and focused(2)
______Appropriate vocabulary and complete sentences are used (2)
______Proper spelling and grammar (2)
______References are properly cited. (4)

Oral Presentation (18 pts.)

______Content (6)
______Discussion of problems of construction and operation (3)
______Laboratory data is presented (3)
______Eye contact with audience (2)
______Speaks clearly with good volume (2)
______Demonstrates understanding in responses to questions (2)

Written Report, individual (12 pts.)

______Content (4)
______All questions are addressed (2)
______References are included (2)
______Writing is organized and focused (2)
______Appropriate vocabulary and complete sentences are used (1)
______Proper spelling and grammar (1)

Total ______

Math, Science, Technology and Everyday Connections

The project is to construct a working solar oven. This process involves scientific inquiry, imagination, application of scientific knowledge, manipulation and trial and error, brought together to achieve a solution which must work. Mathematics is essential in the project, as it is vital to compute various measurements of the product and analyze heat and temperature parameters. Technology is involved in the design and completion of the product that may be used for a specific purpose by mankind. This leads to its everyday use by people who choose to use an alternative source of energy for their cooking requirements. Students may also access and transfer information via the technology of the computer.

Students are expected to have learned concepts, principles and theories about energy, specifically thermal energy. They must be aware of the conversions of solar energy into thermal energy, absorbers and reflectors of heat energy and sources of energy. In their design, students must apply the concepts of thermal energy, energy conversions and conservation, efficient reflectors and absorbers of light and heat energy, insulation, heat and heat transfer. The efficiency of the oven would be examined by the goal to melt cheddar cheese on nachos, a socially satisfying aspect.

Measurements of temperature inside the oven and externally for comparison are recorded daily at appropriate intervals and then graphed. The heat gain is calculated. Calculations of benefits to costs in comparison with other energy sources may be performed. At each step, students analyze and interpret the data.

Final assembly of all the materials, energy and information to form a useful product based on a blueprint is the technological aspect of the project. Also important are suggestions for its possible improvement.

In designing the solar oven, students connect the common themes of mathematics, science and technology. The product meets the everyday social need of cooking food.

Instructional Design/Methods and Strategies

Students participating in this activity benefit from its hands-on nature and the use of inquiry. The hands-on task (building the oven) allows the students to be fully engaged; the inquiry component (design, experiments, observations, research) generates curiosity.

In addition to math, science and technology, students, through the written and oral portions of the project, will have to integrate their communication skills as well. By working in groups, students will experience collaborating as a team to complete a task.

This project is very flexible and with the right amount of planning it can take 2 weeks or up to 6 months. In this outline the project will take place over the course of 2 - 3 weeks. In a physics class this would come sometime within the unit on energy. In environmental science it could be placed at the end of an energy unit when discussing alternatives to energy sources or in the natural resources unit. Depending on the time frame teachers can also have students work on this project individually at home.

It is important that the teacher identify a room that can be used throughout the day for the ovens. The best place would be a room facing the south with large windows. Another option is the roof of the building as long as the students have access to it. If a teacher decides to use an outdoor space it must be at least 35 degrees F outside for the ovens to warm to 200 degrees.

Identifying the change in temperature over the day is important for the students to see and understand. The students will be required to take an initial temperature in the morning as well as at the end of the day. During lab period, or another chosen time slot, the students should take the temperature.

Cross- and Interdisciplinary Links

In addition to physics and math, this project incorporates aspects of earth science, chemistry and biology. The relationship between earth movements and the sun causes the change of seasons, which is responsible for the amount of solar energy that reaches a particular area of the earth at a point in time. The study of energy addresses the change of state of matter when heat is applied. In biology, there are considerations of the homoiothermic and poikilothermic nature of animals. Humans are homoiothermic and it is essential for us to maintain a constant body temperature. Therefore, the type of clothing that we wear during different seasons of the year is of importance for heat loss or gain. This can be extended to the issue of global warming, which has already been predicted to be potentially dangerous, particularly concerning the melting of the ice caps at the earth’s poles.

Art and language skills are also addressed. The project includes a graphic illustration of the product design, which is assessed on clarity and neatness. The written report requires a precise, organized detailed description of the project. A precise, effective oral presentation is also expected.

The student is required to research answers to cultural and technological questions for inclusion in the essays. Answers must address the use of solar ovens in the U.S. and in other areas of the world, today and in the future. This is linked to cooking by various cultures. Historical information on solar cooking must be included.

Gender & Ethnicity Issues

Student groups are heterogeneous and engaged in a universal activity – cooking. Hopefully, students will have seen a stove, oven, toaster, toaster oven, microwave, hot plate, charcoal grill, or wood fire. Some students may have used a solar oven.

Science and MST Standards Addressed

This project addresses the national science standards (1-7) and the New York State MST Standards (1,2,4,5,7).

Implementation Plan

In order for the solar-oven lesson plans to be implemented, three factors will be key:

1. Access to an appropriate room. The optimal lab room faces south and is exposed to the sun.

2. Supervision support. The department must be open to innovation and supportive of change.

3. Convincing the students of the value of the project and their likelihood of success.

Evalution/Assessment Plan

The assessment plan is designed so that the student is aware of the grading criteria at the beginning of the project. Critical thinking is emphasized. For instance, not only is a materials list required, but also a justification for the choices. Also required in the group report is a discussion of the problems that were encountered, solutions to the problems and thoughts on what could be changed, thereby allowing students to reflect on their own work. The design and quality of the oven was weighed heavily when allocating grade points. However, the importance of communication skills is stressed through the inclusion of written and oral presentations. Lastly, an individual component is included to make the students more comfortable if they were not yet accustomed to working in groups.

Bibliography

Hewitt, P. G. Conceptual Physics. Menlo Park, CA: Scott Forsman-Addison-Wesley-Longman. 1999.

Marzano, R.J., Pickering, D. and McTighe, J. Assessing Student Outcomes. Aurora, CO. ASCD Publications. 1999.

National Renewable Energy Laboratory. www.nrel.gov/business/education/pizzabox.html

New York State Education Department. Regents physics syllabus. New York State Department of Education.

Spears, J. D., & Zollman, D. The Fascination of Physics. Menlo Park, CA: The Benjamin/Cummings Publishing Company. 1985.

Zitzewitz, P. W., & Neff, R. F. Merril Physics: Principles and problems. Westerville OH: Glencoe/McGraw-Hill. 1995.