Converting Solar Energy To Heat Energy

The albedo effect is a measurement of the amount of solar energy that is reflected back into space. When the sun shines on Earth, some of the sun's energy is absorbed by Earth's atmosphere and Earth's surface. A small percent of the Sun's energy is also reflected by the atmosphere and by Earth's surface. You have experienced this phenomenon while sitting inside of a car that has its windows rolled up. Before the sunlight enters the car's interior, it has a higher energy than it does after entering. Different materials inside the car affect this energy by absorbing some of it and reflecting some of it at lower energy. The reflected energy is usually in the form of infrared radiation or heat. This is why the inside of the car warms up. Many factors determine the ability an item's ability to reflect and absorb energy from the sun.

Objective: This activity will allow you to observe how colors can affect heat transfer through the albedo percent of each color.

Procedure:

1. Create boxes out of several different sheets of colored-paper.
2. Tape a sheet of plastic wrap over the open end of each box.
3. Punch a small hole (large enough for a thermometer) and insert the thermometer into the hole.
4. Tape over any place on your boxes where heat might leak out.
5. Place each of the boxes in sunlight for 15 minutes and record the temperature readings for each box every one minute. Write this information in the data tables provided.
   
6. Graph your data.
   

Analysis:

1. Which of the boxes had the highest final temperature?
2. Which of the boxes had the lowest final temperature?
3. Which of the boxes had the greatest increase in temperature over the shortest span of time?
4. What relationship did you find between the color and the temperature of the box?
5. Identify several variables that you could change to alter your results of this experiment.
6. Besides asthetic values, what are some important uses of color by humans?

Extension:

1. Obtain several cups of different soils and compare the rate at which each warms and cools.
2. Compare the heating and cooling rate of water with that of the heating and cooling rate of soil.
3. Compare the heating and cooling rates of cement and asphalt, grass and sand, air and water, cotton and wool, nylon and cotton, etc.