Teachers TryScience

Solar Cooker

Apr 10 2016

Source: vascsc-tts-guj

Summary Information

Keywords:

Energy, sunlight, cooker, environment, reflection of light

Topic:

Earth Science

Measurement

Physical Science

Physics

Workplace Skills:

Raising Questions

Investigation Design

Discussion

Recording & Reporting

Estimated Time Required:

5-8 hours

Target Grade (Ages):

Grade 5 (Ages 10-11)

Grade 6 (Ages 11-12)

Grade 7 (Ages 12-13)

Grade 8 (Ages 13-14)

Diversity Indicators:

This lesson is suitable for students of Grades 5-8 who are in a multi level classroom.

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LESSON

Goals and Prerequisites

Goals:

1. To enable the students to apply the concept of renewable energy (here, solar energy) conservation.

2. To enable the students to design, construct and evaluate the solar cooker.

Prerequisites:

Knowledge of reflection of light.
Law of Conservation of Energy.

Instructional Objective(s)

At the end of the lesson, the students will be able to:

1. Recall, discuss and explain the concepts of energy conservation

2. Explain & discuss the concepts of reflection of light

3. Design & construct different types of solar cooker

4. Demonstrate the use of the solar oven in conserving energy

Instructional Resources

Background:

India has a tremendous scope of generating solar energy as it receives solar radiation which amounts to 3000 hours of sunshine every year. States like Andhra Pradesh, Bihar, Gujarat, Haryana, Madhya Pradesh, Maharashtra, Orissa, West Bengal, Punjab and Rajasthan have great potential for trapping solar energy due to their location.

Solar Cooker is a device which uses the energy of direct sunlight to heat or cook food. Solar Cookers work on the principle of conversion of solar energy (light energy) to heat energy. Solar energy is considered to be the most economical form of renewable energy.

Types of Solar Cooker:

Solar Oven
Solar Panel Cooker
Parabolic Solar Cooker

The solar funnel cooker usually consists of:

1. A cooking vessel that is painted black.

2. An oven cooking bag (ordinary polyethylene melts too easily) or transparent glass bowl.

3. Reflective panels made from aluminium foil over a corrugated carton / cardboard.

The reflector panels concentrate the sunlight onto the cooking vessel containing the food. Some funnel cookers can achieve relatively high temperatures depending on the pot and the food being cooked. Food cooks faster during the two hours before and after the local solar noon. It is difficult to burn food in a solar cooker.

scooker_-_gujarati.pdf

Materials:

Materials:
Cardboard, aluminium foil, glass jar with a lid, black colour acrylic paint, transparent bag, stapler, cello tape, glue, scissors, compass, a scale and a pencil, pictures of making of Solar Funnel Cooker

Procedure:

Take a rectangular piece of cardboard of minimum length ‘48cm’ and breadth ‘64cm’.
Measure the diameter of your cooking vessel. Use this diameter as the radius to draw a semi-circle along the bottom of the cardboard and cut the edge out as shown in the figures above.

For e.g., if the diameter of the cooking vessel is 7 cm, then the radius of the semicircle should be 7 cm.

Diameter of the cooking vessel = _________ cm

Stick the aluminium foil onto the inner side of the cardboard using glue. Try to smooth out the foil as much as you can.
Join side A to side B using a large stapler and cello tape, to keep the funnel together.
For the cooking vessel, we take a glass jar with a lid and colour it black using acrylic paint.
Place the cooking vessel inside the plastic bag and close the opening to trap the heat.
Place it on top of a wooden block/ brick, inside the funnel cooker.
Place the Solar Funnel Cooker in a way that it gets as much sunlight as possible.
For longer cooking times, readjust the position of the funnel to follow the sun's path.

This finishes the assembly of your solar funnel cooker.

At this stage, you are ready to put food items or water into the cooking vessel or jar, and put the lid on loosely.

Do’s and Don’ts of Solar Funnel Cooker:

- When you are not using your solar cooker, store it away from sunlight in a dry place.

- No matter which type of solar cooker you use, always wear sunglasses!

- Use cooking pads or gloves when handling the hot cooking vessel. It gets very hot!

- For long cooking times (over about an hour), readjust the position of the funnel to follow the sun's path.

Extensions

Extensions:

Students can compare the effect of different intensities of light on the efficiency of the solar cooker.
Students can compare the efficiency of the basic solar oven with one other design.
Students can test the working and efficiency of the cooker using several solar cooking recipes.

Assessments and Rubrics

Solar Cooker Recipes:
1. Solar Baked Potatoes
Inside a dark, covered pot place 2 or three medium size, whole potatoes. Let them bake all day in sun. Set the cooker as per the sun’s direction and just leave it for 3 – 4 hours! Garnish them with salt, pepper and other spices or just eat them plain.

2. Solar Cooked Rice
Take 2 cups of rice, wash it with water. Then, take 3 cups of water and mix both (rice & water) in the black vessel. Put the vessel in your Solar funnel Cooker. Set the cooker around 4 – 5 hours according to the direction of sunlight. Check whether your rice is cooked or not.

3. Solar cooked Popcorn
Initially, heat the vessel using solar cooker and then put the popcorn mix in the vessel. Close the container and keep it in Solar Cooker. Keep checking the corns every 20 mins.

External Resources

http://solarcooking.org/plans/funnel.htm

https://www.teacherstryscience.org/lp/where-theres-light-theres-hot-food

http://www.electronicshub.org/solar-cooker-information/

http://solarcooking.wikia.com/wiki/Recipes

RESOURCES