Introduction

Every day, we use energy, sometimes without really thinking about it. When we turn on lights, keep food cold in the refrigerator, wash clothes in the washing machine, or cool down on a hot day using a fan or air conditioning, we are using energy. But did you know that two devices can do the same job while using different amounts of energy?

In this activity, you’ll explore what energy efficiency means, and how doing the same job with less energy can make a big difference. Along the way, you’ll discover that being energy efficient isn’t always easy. It often means making smart trade-offs between energy use, cost, and comfort.

Part 1: The Paper Fan Test

This activity helps you understand energy efficiency as smarter design; doing the same job using less effort.

Materials: 

• 2 sheets of paper
• Stopwatch or timer

Instructions: 

1. Pick up the flat piece of paper, and use the timer to fan your face for 10 seconds. 
2. Notice how much air you feel on your face, and how much effort it takes. 
3. Next, work as a team to fold the second sheet of paper into a design that would move more air toward your face more efficiently, with less effort. 
4. Fan your face again for 10 seconds, and use the table below to compare the two designs. 

The Paper Fan Test Data Table

Part 2: Energy Efficiency in Everyday Life

Just like your paper designs, some devices are designed to do the same job using less energy. Instead of comparing paper shapes, you will now compare the energy use of real devices.

What are kilowatt-hours (kWh)? 
A kilowatt-hour (kWh) is a unit that measures how much electricity a device uses over time. It combines how much power a device needs and how long it runs. Utility companies use kilowatt-hours (kWh) to calculate how much electricity a home uses and how much it costs. 

Devices that use more kWh per year use more electricity to do their job. Devices that use fewer kWh per year do the same job more efficiently. 

More Efficient or Less Efficient? 
For each device below, decide whether it’s more efficient or less efficient based on its annual energy use.

Part 3: Home Energy Design Challenge

Efficiency matters, but it often costs more. In this challenge, you must balance energy use, cost, and comfort. Your goal is to design a home that stays under the budget and below the energy limit. 

Before you begin designing your home, study the information chart below. These charts show the energy use (kWh/year) and cost of different appliances. You will use this information to make all of your decisions.

What is Upfront Cost?

Upfront cost is the amount of money you have to pay right now to buy a device. Even if a device saves energy and money over time, a high upfront cost can make it hard for people to afford it.

Many energy-efficient devices are cost-effective over time because they use less electricity, which lowers energy bills. However, families still have to make decisions based on what they can afford today. This activity focuses on upfront cost and yearly energy use to show why efficient technologies are not always adopted right away.

Appliance Information Chart

Your Design Challenge

Option A Data Table: One Choice Per Category
Rules: Budget Limit: $5,000; Energy Limit: 7,000 kWh per year; Choose only one item per category

Reflection Questions

1. Which choice saved the most energy for the money you spent? Explain how that choice helped you meet the energy goal. 
   
   
   
   
   
   
   
   
   
   
   

2. Which item(s) did you choose to keep less efficient, and why? Was it comfort, cost, or something else? 
   
   
   
   
   
   
   
   
   
   
   

3. If electricity prices doubled next year, which item would you upgrade first?
   
   
   
   
   
   
   
   
   
   
   

4. How does this activity show that efficiency is about smart decisions, not just saving energy?
   

Your Design Challenge

Option B: Build a Small House System

House Assumptions 

• 3-bedroom
• 1,200 sq ft
• Lighting (30 bulbs total, required)
• TVs (choose 0-2)
• Computers (choose 0-2)
• Cooling (choose one approach, multiple devices allowed)

Limits

• Budget: $6,500
• Energy Limit: $7,000 kWh/year

Option B Data Table

Reflection Questions

1. Which choice was the best deal? Explain what made it a smart choice.
   
   
   
   
   
   
   
   
   
   
   

2. Where did you spend extra money for comfort or convenience? 
   
   
   
   
   
   
   
   
   
   
   

3. If you had to remove one item to save money, which would it be, and why? 
   
   
   
   
   
   
   
   
   
   
   

4. Why can’t most people buy all efficient appliances at once?