# LessonHousehold Energy Conservation and Efficiency

### Quick Look

Grade Level: 8 (6-8)

Time Required: 2 hours

(three 40-minute class periods)

Lesson Dependency:

Subject Areas: Physical Science, Science and Technology

### Summary

Students complete three different activities to evaluate the energy consumption in a household and explore potential ways to reduce that consumption. The focus is on conservation and energy efficient electrical devices and appliances. The lesson reinforces the relationship between power and energy and associated measurements and calculations required to evaluate energy consumption. The lesson provides students with more concrete information for completing their culminating unit assignment.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

### Engineering Connection

Evaluating energy consumption is the first step engineers must take when trying to reduce energy consumption. This step is part of the "understand the problem" and "gather information" steps in the problem solving spiral.

### Learning Objectives

After this lesson, students should be able to:

• Calculate energy use and analyze how changing behaviors and appliances affects energy use.
• Conduct an experiment and make comparisons based on experimental evidence.

### Educational Standards Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards. All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org). In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

###### NGSS: Next Generation Science Standards - Science
• Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion). (Grades 6 - 8) More Details

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• Collect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions. (Grades 6 - 8) More Details

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• Use mathematical representations to describe and/or support scientific conclusions and design solutions. (Grades 6 - 8) More Details

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• Analyze and interpret data to determine similarities and differences in findings. (Grades 6 - 8) More Details

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• Typically as human populations and per-capita consumption of natural resources increase, so do the negative impacts on Earth unless the activities and technologies involved are engineered otherwise. (Grades 6 - 8) More Details

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###### Common Core State Standards - Math
• Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation. (Grade 6) More Details

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• Summarize numerical data sets in relation to their context, such as by: (Grade 6) More Details

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• Reporting the number of observations. (Grade 6) More Details

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###### International Technology and Engineering Educators Association - Technology
• Energy can be used to do work, using many processes. (Grades 6 - 8) More Details

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• Analyze how the creation and use of technologies consumes renewable and non-renewable resources and creates waste. (Grades 6 - 8) More Details

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###### National Council of Teachers of Mathematics - Math
• recognize and apply mathematics in contexts outside of mathematics (Grades Pre-K - 12) More Details

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###### National Science Education Standards - Science
• Use mathematics in all aspects of scientific inquiry. Mathematics is essential to asking and answering questions about the natural world. Mathematics can be used to ask questions; to gather, organize, and present data; and to structure convincing explanations. (Grades 5 - 8) More Details

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• Mathematics is important in all aspects of scientific inquiry. (Grades 5 - 8) More Details

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• Energy is a property of many substances and is associated with heat, light, electricity, mechanical motion, sound, nuclei, and the nature of a chemical. Energy is transferred in many ways. (Grades 5 - 8) More Details

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• Electrical circuits provide a means of transferring electrical energy when heat, light, sound, and chemical changes are produced. (Grades 5 - 8) More Details

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###### New York - Math
• Fluently add, subtract, multiply, and divide multi-digit decimals using the standard algorithm for each operation. (Grade 6) More Details

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• Display numerical data in plots on a number line, including dot plots, histograms, and box plots. (Grade 6) More Details

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• Summarize numerical data sets in relation to their context, such as by: (Grade 6) More Details

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Suggest an alignment not listed above

### Introduction/Motivation

How are your unit projects going? Have you come up with some good ideas about how you might reduce your energy consumption? In this lesson, we will explore more closely how we use energy in our homes and identify some ideas for conserving energy or using it more efficiently. Recall these terms:

• Conservation – not using consumer energy products (for example, turning lights off, walking instead of driving)
• Efficiency – benefiting from the value of using energy (for example, still being mobile), but consuming much less energy to meet same goal (for example, using an automobile with high miles per gallon)

We use energy in our lives everyday. Our homes use energy in many ways. Home heating/cooling systems are the largest consumer of energy in most U.S. households. Heating water is also a large energy consumer. Refer to the three associated activities: Watt Meters to Measure Energy Consumption, to illustrate the energy used from various electrical devices and household appliances using various approaches over a 3 day lesson plan.

Another large energy consumer category is electric lighting and appliances. (Refer to data in the Excel graphing activity, lesson 1, for specific information.) Our homes are filled with appliances that use electrical energy to work for us. Toasters, microwave ovens, televisions and computers are examples of the appliances we use everyday. We compare electrical energy use in units called watt-hours or kilowatt-hours. Lighting accounts for 20-25% of all the electricity used in the U.S. On average, a household uses 5-10% of its energy for lighting. A commercial industry on the other hand consumes 20-30% of its energy in lighting alone; 50% or more of the energy used is wasted by obsolete equipment, inadequate maintenance, or inefficient use.

Consumer demand for appliances that turn on quickly and LED lights that stay on all the time creates a constant "stand by" power requirement that can be very substantial. This power is sometimes called "leaking electricity." Unplugging these appliances is the only way to reduce the stand by power load. (Show some examples on computer, TV, other appliances that might be in the classroom.)

Energy savings for lighting will require either reduction in use or more efficient usage. New technologies have provided significant reductions in the power needed for lighting.

### Lesson Background and Concepts for Teachers

The use of electricity in the home was addressed in the graphing activity of lesson 1. Many of the concepts covered here were introduced (superficially) in that lesson. The general concepts of this lesson include:

1. Energy conservation can be defined as the protection, preservation, management, or restoration of our energy resources.
2. Conservation is one of the ways we can reduce energy use, thus reducing the amount of pollutants put into our atmosphere from the burning of fossil fuels and reducing the negative effects resulting from the combustion of these fuels.
3. Conservation methods include modifications to our daily behaviors to reduce energy consumption (for example, turning off lights).
4. Efficiency can be achieved by choosing energy-efficient products. These products still provide work, light or heat, but do so with less energy consumption than less-efficient products.

Light Bulb Options

75W incandescent equivalent bulbs

Compact fluorescent light bulbs (CFLs)

See photo and product description at EarthEasy's website: http://eartheasy.com/live_energyeff_lighting.htm

• Wattage: 18 W (76% energy savings)
• Lasts: 8,000 hours
• Cost: \$22 per pack
• Requires special bulb recycling to collect and contain mercury

Cold cathode fluorescents (CCFLs)

18 watts = 75 watt incandescent equivalent

See photo and product description at: https://www.jacksonelectricsupply.com/BF40U20205_19B_p/bf40u20205-19b.htm

• Wattage: 18 W (76% energy savings)
• Lasts: 25,000 hours
• Low energy costs; less mercury then CFLs

Light Emitting Diode (LED)

The 5 Watt LED light:

• is efficient and cost effective
• is the most powerful direct replacement bulb
• fits standard sockets

See photo and product description at EarthTechProducts at: http://www.earthtechproducts.com/energy-saving-led-light-bulbs.html

• Wattage: 5 W (93% energy savings)
• Cost: \$60
• No mercury; expensive

### Associated Activities

• Watt Meters to Measure Energy Consumption - (Day 1) Students use watt meters to measure the power required and calculate energy used from various electrical devices and household appliances.
• Household Energy Audit - (Assign Day 1, Day2) Students review the electrical appliances used at home and estimate the energy used for each. The results can help to show the energy hogs that could benefit from conservation or improved efficiency. Combination in-class and homework activity.
• Light vs. Heat Bulbs - (Day 3) Students measure the light output and temperature (as a measure of heat output) for three types of light bulbs to identify why some light bulbs are more efficient (more light with less energy) than others.

### Vocabulary/Definitions

compact fluorescent lamp : (CFL) A modern light bulb that converts electricity into light through the excitation of

energy audit: A study of energy use and losses in a home, business or other system.

incandescent bulb: Traditional light bulb that converts electricity to light by heating a thin wire until it glows.

LED: A light emitting diode is a solid-state semiconductor device that converts electrical energy directly into light. The process of an electron moving in the semi-conductor releases energy and produces photons with visible wavelengths.

life cycle cost analysis: Analysis of the total capital and operating cost of a product.

### Assessment

Worksheet & Homework: Assign students the Light Bulbs Activity Worksheet and Homework. The homework may be redundant if a thorough home energy audit is also done.

Homework & Activity Sheets: Assign students the home energy audit homework/activity sheets.

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### References

Energy Star. Compact Fluorescent Light Bulbs, U.S. EPA and U.S. Department of Energy. Accessed December 30, 2008. https://www.energystar.gov/index.cfm?c=cfls.pr_cfls

### Other Related Information

This lesson was originally published by the Clarkson University K-12 Project Based Learning Partnership Program and may be accessed at http://internal.clarkson.edu/highschool/k12/project/energysystems.html.

© 2013 by Regents of the University of Colorado; original © 2008 Clarkson University

### Contributors

Jan DeWaters; Susan Powers; and a number of Clarkson and St. Lawrence University students in the K-12 Project Based Learning Partnership Program

### Supporting Program

Office of Educational Partnerships, Clarkson University, Potsdam, NY

### Acknowledgements

This lesson was developed under National Science Foundation grant nos. DUE 0428127 and DGE 0338216. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.