Grade Level: 6th – 8th grade
Subject Matter: Physical Science
National Standards: NS.5-8.1, NS.5-8.2, NS.5-8.5
(All materials listed are for each student or each group of students)
Shoebox with lid
Four insulated wires with alligator clips
Two 6-volt mini-bulbs with socket base
Mini-solar panels with alligator clips
Sustainable: capable of being continued with minimal long-term effects on the environment.
Photovoltaic: a material that converts light energy into direct-current electricity.
Resistor: an electrical device, such as a light bulb, that resists the flow of an electrical current.
Simple circuit: a pathway for electricity to flow in one continuous path. A simple circuit consists of one electrical source, one conductor and one resistor.
Series circuit: a pathway for electricity to flow in one continuous path that consists of multiple resistors connected in a series.
Parallel circuit: a pathway for electricity that consists of multiple pathways and resistors.
1. Start the lesson by having students watch the Science Friday Video, “Creating A Living Building.” Ask students what they see on the roof of the Living Learning Center building. Have students give examples of other solar-powered products or items that they have seen in their daily lives.
2. Inform students that they will be exploring how solar panels work and creating a model of a solar-powered house.
Activity 1 – Solar Panel Exploration
1. Distribute one mini-solar panel, four insulated wires with alligator clips and two light bulbs (with their socket bases) to each team of students. Have students examine their solar panels and discuss their observations.
2. Challenge students to use each solar panel to power a light bulb using a simple circuit. Have students explain how they are able to make the bulb light up. Where is the electricity coming from? Where did they have to place their solar panel in order to generate electricity?
3. Challenge students to power two light bulbs in a series circuit. Have students explain how the connection was made. Do both bulbs light up with the same brightness?
4. Challenge students to power two light bulbs in a parallel circuit. Have student explain how this connection is made. Do both light bulbs light up with the same brightness?
1. Hand out a shoebox to each team of students. Challenge students to wire each house with a light bulb inside that is powered by the solar panel. Students can use scissors to punch holes in the shoebox to run the wires, and electrical tape to hold the wires and light bulb in place.
2. Once students have completed their houses, have them expose the solar panel to sunlight. Does the bulb light up the inside of the house? Remove the house and solar panel from the sunlight. Does the light remain on? How long does it take for the light bulb to turn off?
3. Have students test the following variables:
- a. Tilt the solar panel at various angles. Does the tilting affect the light bulb’s performance?
- b. How much time passes between the solar panel’s direct exposure to sunlight and the light bulb’s turning on?
- c. Does the solar panel work on a cloudy day or in the shade?
- d. Can the solar panel power two light bulbs inside the house?
4. Discuss with students what they have found out from their observations about the advantages and disadvantages of using solar energy. Have students create a list of the challenges of using solar energy, and then discuss possible methods for solving these problems. For example, could they use rechargeable batteries to store energy to rely on when sunlight is not available?
Solar panels are made of photovoltaic (PV) cells that convert light energy into electrical energy. In the PV cell, energy from sunlight causes negatively charged electrons to move to the top of the cell, while more positively charged protons remain in place. This movement causes one side of the cell to be mostly negative and the other to be mostly positive, similar to a battery. This movement also energizes the cell to instantly create an electrical current when a complete circuit is connected to the solar panel. However, the movement of electrons only continues as long as the PV cell is exposed to sunlight. PV cells themselves cannot store energy for later use. Battery chargers are often used with solar panels to store and provide energy when there is no sunlight available.
• What are some of the advantages/disadvantages to using solar energy, as opposed to more traditional sources of energy such as oil, coal, or natural gas?
• Why do houses or buildings have more than one solar panel on their roofs?
• Why haven’t solar-powered cars entirely replaced gasoline- powered cars?
Extend this activity by having students construct a four-room house with additional appliances that use solar power. A four-room house can be created using a cardboard box and two cardboard pieces with slits to form a T-shape inside the box. Additional appliances can include mini-light bulbs to light each room and a buzzer to act as a doorbell.