Did you know that in just one hour the sunlight shining down on the earth could meet the world’s energy demand for an entire year? People have used the sun as a free and easily accessible heat source for thousands of years. For example, ancient Greeks built their homes to get the most sunlight during the cold winter months. In the modern world, solar energy is used for heating water for domestic use, space heating buildings, and generating electrical energy.
Photovoltaic devices, such as solar panels, are able to directly convert solar energy into electricity without consuming any fossil fuels. This operation is based on the photovoltaic effect; an observed occurrence of an electric current being produced when light energy strikes the surface of a certain semiconductor. A semiconductor is a substance with electrical properties, classified between a good conductor and a good insulator.
A semiconductor is a tricky matter to explain to grade-schoolers. However, no one said we have to teach it in scientific terms. If we think outside of the box, we may come up with a child-friendly story about athletic electrons on a circuit track. Let’s imagine a track where instead of a start line, there is a deep trench. The electron athletes all stand on one side of the trench, but to make it even more difficult, they are stuck in glue. The electron athletes become weak from trying to escape the glue and are soon unable to move at all. If only they had enough power to rip their shoes out of that glue and then jump over the trench, they would be free to run a lap. Upon return to the trench, they would see an empty, sticky spot left by another run-away electron athlete. Luckily for them a lightning bolt from the sky occasionally strikes one of the electron athletes, giving them enough power to take off, jump over the trench, and run a lap. When electrons run, we are talking about an electric current. This is how the energy from lightning bolts (or photons) is transformed into an electric current.
A good thing for parents or teachers to do before making up a metaphor of your own would be to first explore the adult-level explanation of the phenomena. Consider checking out these great resources:
Unlike homemade batteries and electromechanical generators, the solar cells are quite difficult to make at home with your child.
However, if you have enough patience and don’t mind a trip to the hardware store, you might want to make your own photovoltaic cell from scratch. Check out this post on scitoys.com.
If you don’t like the idea of soldering or messing with hot glue, go ahead and check out these educational solar panel kits you can easily buy online.
Whichever DIY solar panel project you choose, it is always a great idea to supplement the exploration experience with interactive virtual models. Check out the solar panel lab in our app ‘How to Make Electricity‘. There you can discover the effects weather conditions, bird droppings, and other circumstances have on the efficiency of the solar panel.