Energy Excursions

Energy Exercise: The Luxury of a Shower

"Can potatoes power the planet? Complete the energy exercise to find out!"

Summary

This lesson introduces a hands-on energy exercise in order for students to gain a new perspective on the energy intensity of modern society and our standard of living. Using the example of a twenty-minute hot shower, students will solve a series of basic calculations and conversions to determine how much energy, measured in British Thermal Units (BTU) is required to heat enough water for that luxury shower. How will this energy be produced? Using “human horsepower,” students will determine if they can produce enough energy by repeatedly lifting and dropping a five pound sack of potatoes (one lift and release is equivalent to a single cycle). Students will also determine how many cycles are required to produce enough energy to heat water for one twenty-minute shower, and roughly how long it will take to produce enough energy. Students will also contemplate the rate at which energy is delivered to the ‘shower system’ and why they might need a group of people, rather than just one individual, to heat the water for the shower.

Learning Outcomes 

  • Students will gain perspective on energy consumption and energy intensity in modern society 
  • Introduction to a series of calculations/conversions to determine necessary energy production 
    • How much energy (BTU), is required to heat water for a twenty-minute shower? 
  • Students will complete an energy exercise, The Luxury of a Shower, to gain an understanding of how energy intensive human activities are in the United States, such as a twenty-minute shower 
    • How much human horsepower is required to heat water for a twenty-minute shower? 
    • How long must a “human power plant” work to supply enough energy required to heat water for a twenty-minute shower? 
TEKS Standards
College Board Units and Topics