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.

An alternative way for the students to calculate the energy coming from the PV cell is to measure the voltage and the current output from the PV cell across a resistor and use the equation P = IV to calculate the power produced. This way is planned out in the labs related to this unit. From here the students use the efficiency of the PV cell and the area of the cell to calculate the energy of the sun at that time of day. Students will also experiment with different color filters to determine the energy output of the solar panel at different wavelengths. This will allow them to determine the spectrum of light in which the sun emits the most energy. The activities are:

• Measuring the power from the sun
• Measuring the sun's spectrum
• How much PV do you need?
• Energy use in the home
• Traditional electricity vs. photovoltaics
• Photovoltaics vs. coal-produced electricity

Handouts included; photovoltaic solar cells with attached resistor, 10 Ohm (prices range from $6-20); color filters (clear, red, green, blue, black), “Ray box color filter set”; five cardboard boxes (shoe boxes work well, students can donate from home); and five plants (any greenhouse, $2-3 per plant).

Science Content Standards: 5-8

CONTENT STANDARD A: Science as Inquiry

• Abilities necessary to do scientific inquiry
• Understandings about scientific inquiry

CONTENT STANDARD B: Physical Science

• Conservation of energy and increase in disorder
• Interactions of energy and matter

CONTENT STANDARD D: Earth and Space Science

• Energy in the earth system

CONTENT STANDARD E: Science and Technology

• Abilities of technological design
• Understandings about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

• Natural Resources
• Environmental quality
• Natural and human induced hazards
• Science and technology in local, national, and global challenges

CONTENT STANDARD G: History and Nature of Science

• Science as a human endeavor
• Nature of scientific knowledge