The lesson will first explore the concept of current in electrical circuits. Current will be defined as the flow of electrons. Photovoltaic (PV) cell properties will then be introduced. Generally constructed of silicon, photovoltaic 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. Light from the sun provides this energy. This will lead to the principle of "Conservation of Energy." Finally, with a basic understanding of the circuits through Ohm's law, students will see how the energy from the sun can be used to power everyday items, including vehicles. This lesson utilizes the engineering design activity of building a solar car to help students learn these concepts.

Students are introduced to the idea of electrical energy. They learn about the relationships between charge, voltage, current and resistance. They discover that electrical energy is the form of energy that powers most of their household appliances and toys. In the associated activities, students learn how a circuit works and test materials to see if they conduct electricity. Building upon a general understanding of electrical energy, they design their own potato power experiment. In two literacy activities, students learn about the electrical power grid and blackouts.

Using plastic straws, wire, batteries and iron nails, student teams build and test two versions of electromagnets one with and one without an iron nail at its core. They test each magnet's ability pick up loose staples, which reveals the importance of an iron core to the magnet's strength. Students also learn about the prevalence and importance of electromagnets in their everyday lives.

Students examine how the power output of a photovoltaic (PV) solar panel is affected by temperature changes. Using a 100-watt lamp and a small PV panel connected to a digital multimeter, teams vary the temperature of the panel and record the resulting voltage output. They plot the panel's power output and calculate the panel's temperature coefficient.

Kirchhoff's laws are fundamental to circuit theory. They quantify how current flows through a circuit and how voltage varies around a loop in a circuit.

Make sparks fly with John Travoltage. Wiggle Johnnie's foot and he picks up charges from the carpet. Bring his hand close to the door knob and get rid of the excess charge.

Students act as engineers to apply what they know about how circuits work in electrical/motorized devices to design their own battery-operated model motor vehicles with specific paramaters. They calculate the work done by the vehicles and the power produced by their motor systems.

Kirchhoff's Voltage Law says if you travel around any loop in a circuit, the voltages across the elements add up to zero. Created by Willy McAllister.

Students explore the composition and practical application of parallel circuitry, compared to series circuitry. Students design and build parallel circuits and investigate their characteristics, and apply Ohm's law.

Students learn how to find the maximum power point (MPP) of a photovoltaic (PV) panel in order to optimize its efficiency at creating solar power. They also learn about real-world applications and technologies that use this technique, as well as Ohm's law and the power equation, which govern a PV panel's ability to produce power.

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law. The sizes of the symbols in the equation change to match the circuit diagram.

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law. The sizes of the symbols in the equation change to match the circuit diagram.

Students engage in an interactive "hot potato" demonstration to gain an appreciation for the flow of electrons through a circuit. Students role play the different parts of a simple circuit and send small items representing electrons (paper or candy pieces) through the circuit.

See how light knocks electrons off a metal target, and recreate the experiment that spawned the field of quantum mechanics.

See how light knocks electrons off a metal target, and recreate the experiment that spawned the field of quantum mechanics.

Students download the software needed to create Arduino programs and make sure their Arduino microcontrollers work correctly. Then, they connect an LED to the Arduino and type up and upload programs to the Arduino board to 1) make the LED blink on and off and 2) make the LED fade (brighten and then dim). Throughout, students reflect on what they've accomplished by answering questions and modifying the original programs and circuits in order to achieve new outcomes. A design challenge gives students a chance to demonstrate their understanding of actuators and Arduinos; they design a functioning system using an Arduino, at least three actuators and either a buzzer or toy motor. For their designs, students sketch, create and turn in a user's manual for the system (text description, commented program, detailed hardware diagram). Numerous worksheets and handouts are provided.

Student teams measure voltage and current in order to determine the power output of a photovoltaic (PV) panel. They vary the resistance in a simple circuit connected to the panel to demonstrate the effects on voltage, current, and power output. After collecting data, they calculate power for each resistance setting, creating a graph of current vs. voltage, and indentifying the maximum power point.

Students use potatoes to light an LED clock (or light bulb) as they learn how a battery works in a simple circuit and how chemical energy changes to electrical energy. As they learn more about electrical energy, they better understand the concepts of voltage, current and resistance.

Students imagine they are stranded on an island and must create the brightest light possible with the meager supplies they have on hand in order to gain the attention of a rescue airplane. In small groups, students create circuits using items in their "survival kits" to create maximum voltage, measured with a multimeter and two LED lights. To complete the activity, students act as engineers by using the given materials to create circuits that produces the highest voltage and light up the most LED lights. They apply their knowledge of how voltage differs in a series circuit and a parallel circuit to design their solutions.

Students use engineering design principles to construct and test a fully solar powered model car. Several options exist, though we recommend the "Junior Solar Sprint" (JSS) Car Kits that can be purchased with direction from the federal government. Using the JSS kit from Solar World, students are provided with a photovoltaic panel that produces ~3V at ~3W. An optional accessory kit also from Solar World includes wheels, axles and drive gears. A chassis must be built additionally. Balsa wood provides an excellent option though many others are available. The testing of the solar car culminates in a solar race between classmates.