Solar energy is an environmentally
good source of energy because it is non-polluting. However, it isn't
always practical everywhere around the world. Weather conditions
sometimes prevent full use of solar energy. Solar energy, however, is
Concentrating light causes sunlight
to create energy, making some items work. For example, a solar
calculator or solar heater. In this activity, students will learn how to
capture these light rays to make heat energy. Most children learn sooner
or later that a magnifying lens will make paper burn. Students will
learn how light is concentrated and then discover they can create a fire
if not careful.
- This lab is designed to teach
children safety and the power of solar energy.
- On a sunny day, go outside and
give each student a hand lens, 3 dry leaves and a piece of aluminum
foil. (You can always use a piece of paper instead of leaves, but leaves
are safer). Put the leaves on the aluminum foil over a cement or asphalt
area. These areas help concentrate the heat, but are also much safer
when burning any items. Students should see if one, two, or three loupes
makes the leaf easier to burn. Time how long it takes. (If a watch is
available and your students can tell time).
- The 3 lens together will produce
the most concentrated energy, so it will burn the fastest. Students have
to be sure to focus the light before it will burn.
- Students are sometimes confused
between heat energy and light energy. After they finish burning the
leaves, have students rub their hands and then put them on the fickle
foam. If the hand is warm enough, the fickle foam will turn colors (blue
is warmest, reddish is coolest). This is because of heat energy. Shining
light on the fickle foam will produce no change unless the light is
derived from solar light which will also create heat. Heat energy and
light energy are not always the same. However light, if concentrated,
can create heat energy. Remember light can come from more sources than
the Sun. Energy is a complicated subject.