Energy from the Sun
Upon completing this lesson the students will:
• Measure the amount of solar heat that comes from the sun; and
• Describe ways this energy can be used to help reduce our dependence on traditional fossil fuels and nuclear power.
Lesson Partners: The South Carolina Energy Office
Essential Question
How much energy comes to us from the sun?
Grade(s):
- 6
Subject(s):
Recommended Technology:
Other Instructional Materials or Notes:
This activity works well for small groups of students. For each group performing the experiment, you’ll need the following items.
• 2 Styrofoam Cups
• 2 Thermometers
• Food Coloring
• Aluminum Foil
• A Measuring Cup
• A Metric Ruler
• A Watch with Second Hand
• Insulation Materials (packing foam, shredded newspaper, etc.)
• A Cardboard Box (It should be the same height as the cups. Trim the box if needed.)
Lesson Progression
Engage:
Review with the class the background information on solar energy. Ask How can we measure solar energy? Solar energy is measured as heat or calories.
Explore:
Have the students work in small groups to perform this experiment to measure solar energy. Have each group record their results. To set up the experiment, have the students follow these steps.
• Fill two foam cups with a measured amount of very cold water. Set a standard amount for students to use based on the size of the cups.
• To one of the cups of water, add several drops of food coloring to turn the water dark. Make the water as close to black as possible. Black absorbs sunlight.
• To the other cup of clear water, cover the top with a piece of aluminum foil. This foil will reflect the sun.
• Place the cups in the cardboard box. If necessary, trim the box so that it is the same height as the cups.
• Add insulation material around the cups. See the illustration below.
• Place the box in the sun for 10 minutes. The hottest time of the day is usually between 3 and 4 p.m.
• Have students predict what will happen to the water in each of the cups. Instruct students to write their predictions down in their science notebooks.
• After 10 minutes, stir the water in the cups with the thermometers and record the temperatures in a data table.
NOTE: These measurements should be taken at the same time.
Explain:
Have the students evaluate their predictions. Were their predictions correct or incorrect? Have them construct explanations for why their predictions were correct or incorrect. Discuss how darker colors absorb more heat.
Elaborate:
Use these results to do the following calculation to find out how many calories, or the amount of solar heat, received on 1 square centimeter in one minute at your location.
Area = πd = centimeters 4 Calories = ml of H2 O in 1 cup X difference in temperate of both cups after being in the sun for 10 minutes Area (square centimeters) of water X 10
The calories calculation is the same as the amount of solid heat received on 1 square centimeter in 1 minute at your location. Multiply by 10,000 to get the results for 1 square meter.
Explain to the groups that scientists have measured the amount of solar energy beyond our atmosphere at about 2.0 calories per square centimeter per minute. About 1.5 calories per square centimeter per minute reaches earth after passing through the atmosphere. This is called the Solar Constant. Explain to the students that the Solar Constant is important for the study of heat-exchange processes in the earth’s atmosphere and for the investigation of processes occurring in the sun.
Evaluate:
After the experiment, have students consider how this solar energy might be applied to their everyday lives. What inventions or modifications to existing systems do they see as practical for using solar energy? For example, could passive solar energy be used effectively by schools, since most school buildings are not used at night? What about electric school buses? Have the students explain their idea and how it would save nonrenewable energy resources. Have the students reflect on these questions in their Science notebook. Set time aside to have a large group discussion where the students can share their reflections.
E-Learning Activity:
• Online Solar Games and Activities – www.eia.gov/kids/gamesand-activities/
• Colleton Solar Farm – www.santeecoopersolar.com/Solar-Share/ Colleton-Solar-Farm/Index.aspx (Flash is required to view.)
• Illinois Solar Schools Live Dashboard – www.illinoissolarschools. org/solar-schools/ (Pick a school from the A-Z list and click on “Show Solar Data” to see a live look at their solar.)
Solar Energy Information
View ResourceOnline Solar Games and Activities
View ResourceColleton Solar Farm
View ResourceStandards
- Physical Science: Energy Transfer and Conservation
- 6.P.3 The student will demonstrate an understanding of the properties of energy, the transfer and conservation of energy, and the relationship between energy and forces.
Assessments
After the experiment, have students consider how this solar energy might be applied to their everyday lives. What inventions or modifications to existing systems do they see as practical for using solar energy? For example, could passive solar energy be used effectively by schools, since most school buildings are not used at night? What about electric school buses? Have the students explain their idea and how it would save nonrenewable energy resources. Have the students reflect on these questions in their Science notebook. Set time aside to have a large group discussion where the students can share their reflections.
