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 The majority of people using solar cookers (also known as solar ovens) live predominantly in 3rd World countries; especially India, China, Africa and.

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Presentation on theme: " The majority of people using solar cookers (also known as solar ovens) live predominantly in 3rd World countries; especially India, China, Africa and."— Presentation transcript:

1  The majority of people using solar cookers (also known as solar ovens) live predominantly in 3rd World countries; especially India, China, Africa and Tibet.  Many women, especially refugees, trek many miles to obtain cooking fuel, and the reliance on wood for fuel has led to deforestation in many areas. SCI and other organizations help impoverished communities gain access to solar ovens to cook food, pasteurize water and sterilize medical equipment.SCI  Tibet and China are the most prolific users of solar cookers due to their limited firewood supplies – there are few trees in Tibet. Approximately 100,000 solar cookers are sold in China every year.

2  Background information on solar ovens.  In two or three bullets record your background information from your readings, class work or any other source.

3  To have your solar oven able to take in light energy and allow it to raise the temperature of water in a container and to see how long you can retain that heat energy. Compare your model to other class models.  Be sure to rewrite the purpose to fit the topic.

4  Why is your design going to work better than others. Give scientific evidence for your reasoning.

5  Independent variable  Dependent variable  Constants (controlled variables)  Control Group

6  Shoe box  Black paper  Aluminum foil  Plastic wrap  Tape  Other materials from home.

7  Draw a diagram of what your solar oven will look like and label all the parts.  Describe step by step how to build your solar oven.  Explain your testing, include all the steps.

8  Starting temperature of the water, before putting the container in the box.  Temperature of the water after it is in the box for 10 minutes, with the light on.  After shutting off the light, wait 10 minutes again and then check the temperature of the water.  Record the increase in temperature and the decrease in temperature.  Record your groups average temperature.  Record data from each of the groups and compare.

9  Graph the data from your group.  You are graphing the temperature gains.  You are graphing the temperature losses.  Graph your groups average.  Graph the data averages from the various groups.

10  Be sure to (1) accept or reject hypothesis, (2) cite the data, (3) explain why the result is important. The conclusion clearly states what you have found out, and answers the original question. DO NOT RESTATE YOUR HYPOTHESIS VERBATIM. You may refer to it by saying “The hypothesis has been proved false (or correct).” Describe the data in detail, using the actual numbers. Possible explanations of why your conclusion is what it is should be given. This needs to be a well developed  paragraph, using new vocabulary and concepts from the chapter. Be reflective! Incorporate your background information! 

11  Validity:  How valid was this investigation?  What were sources of error? Include Human, Systematic and Random Errors.  How would you improve the experiment if you were to do it over again?   Discussion of Error: Use complete sentences. Discuss where error occurred despite your best efforts. Error is different from mistakes. If you make a mistake in the design of your lab or in the execution of your procedure, you need to redo the lab. Error is not the result of sloppiness. Error is the result of circumstances that were beyond your control, of constants you were unable to keep constant, despite your best efforts.

12  Validity:  How valid was this investigation?  What were sources of error? Include Human, Systematic and Random Errors.  How would you improve the experiment if you were to do it over again?   Discussion of Error: Use complete sentences. Discuss where error occurred despite your best efforts. Error is different from mistakes. If you make a mistake in the design of your lab or in the execution of your procedure, you need to redo the lab. Error is not the result of sloppiness. Error is the result of circumstances that were beyond your control, of constants you were unable to keep constant, despite your best efforts.

13  Basics of a Solar Oven  Most solar cookers work on basic principles: sunlight is converted to heat energy that is retained for cooking.  Fuel: Sunlight  Sunlight is the "fuel." A solar cooker needs an outdoor spot that is sunny for several hours and protected from strong wind, and where food will be safe. Solar cookers don't work at night or on cloudy days.  Convert sunlight to heat energy  Dark surfaces get very hot in sunlight, whereas light surfaces don't. Food cooks best in dark, shallow, thin metal pots with dark, tight-fitting lids to hold in heat and moisture.  Retain heat  A transparent heat trap around the dark pot lets in sunlight, but keeps in the heat. This is a clear, heat-resistant plastic bag or large inverted glass bowl (in panel cookers) or an insulated box with a glass or plastic window (in box cookers). Curved concentrator cookers typically don't require a heat trap.  Capture extra sunlight  One or more shiny surfaces reflect extra sunlight onto the pot, increasing its heat potential.

14  Collecting solar energy  Storing solar energy that has been converted to heat energy  Making your system efficient, example well insulated.  Allow light in but keep heat inside  Must be able to open and close your unit to place water container inside and allow for temperature readings with thermometer


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