Researching, constructing, and testing (student made) Solar Ovens

This activity is designed for students to understand and use alternative energy sources through research of real-world ovens and design of their own solar oven. Students will also further develop and refine their scientific thinking skills through observing, questioning, changing variables in an experiment, problem solving, and scientific writing. Students will understand the basic function of a solar oven, where solar ovens are used, and how they benefit society. They will also understand the reflection and absorption properties of materials.

Vocabulary:

• solar oven
• reflect
• absorb
• benefit society
• insulation
• variable

This activity can be shortened or lengthened to any desired amount of time. Typically for an 8th grade classroom, 3-4 days (block classes of 88 minutes) is required. I have also modified it to work as a 3 day, one hour per day, project for summer school students.

A day for research of the ovens: collecting information and determining/creating their own design for their ovens. A day for creation of the ovens in class - optional, as the ovens could be required to be made at home. Two days to test the ovens outside: first day's test - then evaluation of what variable to change about the oven and perform that change. The next day of outdoor testing to determine if the change made was successful. A final day could be used to compile data, begin writing rough drafts of the scientific paper - allow for peer reviews of those drafts. This activity can be used at any time during the school year, as students only need a basic knowledge of how to carry out an experiment (scientific method) and basic researching & writing skills. No special equipment is necessary, as the ovens can be constructed out of any material desired (any size box-shoe box, storage, etc, aluminum foil, saran/plastic wrap, tape or glue gun, black paper or paint - the choices are yours!)

This activity can be introduced and used in many different places throughout the Earth Science curriculum. It can be used when discussing the sun as the center of the universe and the main source of energy for us or as an extensive experience with performing an experiment through the proper scientific method steps/procedures - further developing the questioning, observing, creating hypotheses, and writing skills necessary in science. Either way, the time of year is important, as obviously direct sunlight is necessary - thus, winter in Minnesota is not a good time for this activity!

You can begin by discussing proper research techniques and methods for finding information on the web and/or in the media center/library. After students are comfortable with how to research, let them do it---leave the learning about what a solar oven is/looks like/etc up to them. (Obviously, monitoring and facilitating along the way - avoiding the simple pizza box ovens, and guiding them to find more detailed information and designs.) After research, come together as a class to share what the students have discovered and allow for sharing/discussion of their designs for their own ovens. Have students explain WHY they chose the design/model they did, and make sure the proper materials are easily obtained. Students then need to construct the ovens - either in class with you, or as an at home project. Either method works, but I have found that at least giving some class time to begin the construction - possibly finished by few, and then completed at home is the best. Leaving it all to be done at home can end in last minute, lower quality projects. The testing of the ovens is clearly weather dependent, and obviously you should have a "back up lesson" in case of clouds/rain/etc. An entire block schedule day (88-90 minutes) can be used for the very first test and the changing of a variable. The following day can then be used for the second test and the beginning of writing of the scientific paper.

During the testing, students will have a thermometer inside their oven. You will alert them at 4-5 minute increments to record the oven's current temperature in a data table. Continue this data collection for a minimum of 45 minutes. When deciding on a variable to change, it's important to make sure students understand they can only choose ONE variable, not the entire design. For example: Do they want to add more foil, a mirror or black paper/paint. Will they change the angle it was sitting at? Will they place it on blacktop rather than on grass? Make it the class goal to see whose oven will have the highest temperature in the class! Then allow them to make this change right there in class, preparing for the second test the following class period.

Following the actual testing and collecting of temperatures, students are required to write up a scientific paper describing the activity and what they have learned. Emphasize the style of scientific writing and proper grammar, works cited, and paper formats/techniques. They will be combining the research they collected before the creation of their oven with the actual building and testing techniques and results into one paper. Peer editing is a great way to refine and complete this paper, as many students may struggle with this part of the activity. Again, a rubric is the most clear and easiest method to asses/grade the paper!

Again, this activity can be modified and changed to fit the needs of your students. The paper could be an optional or extra/challenge opportunity for select students. The type of ovens can be made very basic or pushed to a more complex level depending on materials available, time, and student interest. I originally thought the pizza box style was the easiest and best model for students to use, but giving them more freedom and allowing their own unique designs - steering them away from the pizza box style proved to be much more exciting for everyone - and had higher overall temperatures! Make sure students realize they need to keep their ovens air tight, but still have a way to put the thermometer and food in. The final day of testing - after changing a variable - I allow my students to bring in food to "cook" in the oven - remind them that nothing raw or frozen will typically be cooked enough to eat - keep it simple: s'mores, nachos, etc.

Give the students the basic guidelines, but then let them go - see how creative they can be - that's the exciting part!

A great additional resource - to truly connect this activity to "real life" - is to look at the Solar Oven Society's webpage. http://www.solarovens.org There are current articles about ovens made and sent to developing countries, information/questions about solar ovens, recipes and more. A great addition to the activity!

Students will be assessed on a variety of parts within this activity. Students are required to complete a "research notes sheet" where they will compile the information they find, diagrams, etc about 3 different models of solar ovens used worldwide. Students must participate in the actual creation and testing of their own individual oven. The final scientific paper will be assessed using a rubric format, which the students will be given prior to the start of the activity, along with tips and an outline of the project. http://rubistar.4teachers.org/index.php is a great website for creating rubrics!

8.I.B.1 Scientific inquiry (making observations, investigations, changing variables, etc.)
8.III.C.1 Earth & space, the universe (sun is principle energy source)