Student-Designed Solar Photovoltaics Investigation – Student Handout Part 1

Summary

Part 1: Estimating Energy Demand and Solar Array Size

In Part 1 of the Student-Designed Solar Photovoltaics Investigation, students calculate how much energy is needed to charge their school’s laptops and estimate the size of the solar array required to meet that demand. Working in teams, students research the typical wattage and charging time of a school laptop, then apply the formula Energy (kWh) equals Power (W) multiplied by Time (hours) divided by 1,000 to estimate single-device energy use. They then determine how many laptops should be charged at once, justify their assumptions, and calculate total daily energy demand for the system.

Students next size the solar array. Using a typical commercial panel rating of 300 watts and the average effective sunlight hours for their location, they calculate the ideal number of panels required. Because real-world conditions reduce panel output, students adjust their estimate by 25 percent to account for changing sunlight, panel angle, temperature, shading, and system losses, producing a more realistic panel count. They then calculate the total area and weight of the array, considering how installation site constraints will shape design decisions in Part 2.

This part builds skills in quantitative reasoning, unit conversion, energy and power calculations, and engineering design thinking. It supports NGSS standards including HS-PS3-3 on designing energy conversion devices and HS-ETS1-2 on breaking a major engineering problem into smaller manageable problems. The activity works well as a math-integrated science lesson and is a strong fit for high school physics, environmental science, AP Environmental Science, and engineering classrooms.

Extend the Lesson: Use Part 1 as the entry point to the full Student-Designed Solar Photovoltaics Investigation. Build foundational solar knowledge with the Introduction to Solar lesson, and use the Science of Solar lesson to deepen understanding of how PV panels generate electricity.