From Sunlight to Electric Current
Model solar cars built by middle school students in North Carolina.Copyright 2004 Paul Klenk, Duke University
Students explore the concept of current in electrical circuits, with current defined as the flow of electrons. Then photovoltaic (PV) cell properties are introduced. Generally constructed of silicon, PV cells contain a large number of electrons BUT they can be thought of as "frozen" in their natural state. A source of energy is required to "free" these electrons if we wish to create current. Sunlight provides this energy. This leads to the principle of "conservation of energy." Finally, with a basic understanding of the circuits through Ohm's law, students see how energy from the sun can be used to power everyday items, including vehicles. Engaging students in the engineering design activity of building model solar cars helps students learn these concepts.
Acting as engineers, students build model solar cars, which helps them apply and understand Ohm's law, photovoltaic cells and conservation of energy.
At lesson end, students should be able to:
- Define current.
- Explain why a solar photovoltaic panel is like a battery.