Working in groups, students build simple solar stills filled with salt water and observe what happens when the stills are placed in the sun. The students then taste the water they have collected and discuss what has happened in their stills.
This module addresses issues dealing with the energy from the sun, the energy needs of students in the classroom and, ultimately, our energy needs as a nation. Students will use a photovoltaic (PV) cell to measure the energy from the sun. Using a light bulb with a known wattage, the students will illuminate the bulb using a PV cell. This way the students will know the approximate energy coming from the PV cell.
These nine projects allow students to set up their own investigations and manipulate the variables that influence photovoltaic cells. The projects can be easily integrated into a normal science classroom curriculum, or can be completed by students individually for science fair projects. All of the projects will fit easily into classroom lessons surrounding scientific inquiry and the scientific method. They will also help illustrate concepts in electricity, light and color, velocity and gravity, chemistry and polarity, and could even lead to social studies or social action projects.
As the popularity of photovoltaic (PV) cells and integrated circuits (IC) increases, the need for silicon also increases. Silicon is one of the most used materials in these two industries. It is an inexpensive and abundant semiconductor. However, the process of producing pure silicon adds cost, and it is generally unknown to the public. One of the first steps in producing silicon is a process called carbon-thermic reduction. Silicon dioxide (SiO2) that is found in beach sand and quartz is melted down in a caldron at a temperature of 1450 degrees Celsius.
Areas of the country that have an available coastline but are limited in other renewable resources can use the oceans to produce energy. We are familiar with the large hydroelectric dams that dot our nation, creating large reservoirs and flooding millions of acres of land. By turning to the restless seas we can find a source of energy that is not affected by clouds and the scarcity of wind. By using ocean power we can increase our need for power without having to deplete our existing non-renewable resources.
Students model the flow of energy from the sun as it enters a photovoltaic cell, moves along a wire and powers a load. The game-like atmosphere involves the younger students and helps them understand the continuous nature of the flow of energy. For a related lesson, please see the activity “Solar Powered System” (PDF 430 KB).
Geothermal energy is one of the components of the National Energy Policy: “Reliable, Affordable, and Environmentally Sound Energy for America’s Future.” This lesson includes five activities that will give your students information on the principles of heat transfer and the technology of using geothermal energy to generate electricity.