Lesson Overview

Students will determine the costs of running various appliances based on the cost of electricity in their community and the amount of energy these appliances typically use. Students will the compare these costs to other regions in Alaska.

Target Grades: 6-8

Set Up Time: 30 minutes

Class Time: 1.5 hours

Lesson Resources

Objectives

1. Measure how much electrical energy certain appliances use

2. Calculate the cost of using the supplied appliances for certain periods of time in certain communities

3. Research what factors affect the calculated cost of energy in the community or region

Guiding question: How much energy do our electronics use and how much does it cost to use them?

Educational Standards

ALASKA CULTURAL STANDARDS: B3 & B4

ALASKA ENGLISH LANGUAGE ARTS:
Reading for Informational Text: 6-8 RST.KI.3; 6-8 RST.IKI.7
Writing: 6-8 WSLST.RBPK.9; 6-8 WSLST.RW.10

ALASKA MATHEMATICS: 7.RP.1; 6.NS.2; 7.NS.3

ALASKA SKILLS FOR A HEALTHY LIFE: D1 & D2

ALASKA DIGITAL LITERACY STANDARDS: 6-12.CT.2; 6-12.CT.3

ENERGY LITERACY CONCEPTS: 6.8

NGSS: MS-ESS3-3; MS-PS3-3

Lesson Preparation:
  • Read the Background section below
  • Research the electricity rate in your community. Consult an electric bill or visit your electric utility’s website.
  • Research the method(s) of electricity production in your community.
  • Plug in various electronics around the classroom using electricity monitors
  • If you do not have an electricity monitor, gather electronics that clearly display an Energy Label sticker -OR- provide the link within the Additional Resources where students can research wattage of popular electronics
  • Optional: Download one of the Be an Energy Star Powerpoint Presentations (Anchorage, Kodiak, Fairbanks, or Tok examples)
Gather Materials:
  • Calculating Cost Lab or Calculating Cost student worksheets
  • Electricity Monitors- Poniie or Kill A Watt meter equivalent (if not available, students can use the values written on the appliance Energy Label or research typical wattage using the link in Additional Resources)
  • Calculators
  • Computers with Internet access (optional but helpful)

According to the Alaska Energy Authority’s 2012 End Use Study, residential electricity consumption is quite significant even though the majority of energy consumed in residential buildings in Alaska is used for heating (80% in the Railbelt and Southeast Alaska and 72% in Bethel). Major appliances such as refrigerators, freezers, washers, and dryers consume 24% of the electrical energy in households in the Railbelt and Southeast Alaska and consume 35% of the electrical energy in households in Bethel.

Costs of electricity in Alaska vary greatly from region to region, based on existing infrastructure, available resources, population, etc. Certain communities have relatively low electricity costs compared to others (especially some rural communities) because of local energy resources or subsidies. Anchorage and Juneau have some of the lowest electricity prices in Alaska because of their local natural gas and hydropower, respectively. Energy subsidies from the North Slope Borough lower the price of electricity in Utqiagvik and other North Slope communities. Some communities, such as Noatak, must use planes to fly in all of their fuel for power generation; they rely heavily on diesel, which is expensive to transport in planes or boats, and its prices fluctuates with the price of crude oil. The Alaska Energy Authority’s Power Cost Equalization (PCE) program provides some economic assistance to rural residents with especially high electricity costs.

In Alaska, homes and commercial buildings account for about 14% of all electricity use, which is lower than the national average of electrical consumption. According to the U.S. Energy Information Agency, homes and commercial buildings account for approximately 71% of the nation’s electricity use. With the current trend of increasing energy use, this number is expected to rise to 75% by 2025. Existing residential buildings represent an extremely large source of potential energy savings. Key sources of savings include decreasing inefficient energy use and energy wasted on phantom loads of plug-in appliances. Given that electricity costs are especially high in Alaska, how can you be smart about your electrical usage? How much do our home appliances cost to run each day? Can you use less energy by conserving or using more efficient appliances?  This lesson will help students become more aware of their everyday energy uses and their associated costs.

Energy– The ability of a system to do work; this might refer to either potential or kinetic energy. Potential energy (stored energy) includes chemical, mechanical, nuclear, and gravitational energy. Kinetic energy (motion energy) includes radiant, thermal, motion, sound, and electrical energy. 

Energy Conservation – Reducing energy use through a behavior change that results in not using energy at a time when one might normally. For example, riding a bike instead of driving a car, unplugging computers and other electronics at night or when not in use, or turning off the lights when you leave a room.

Energy Efficiency – Reducing energy use through an improvement in technology that makes an existing use of energy more efficient, i.e. allows us to do more with less.  Examples of energy efficiency include replacing incandescent light bulbs LED’s, adding extra insulation to a house, or using Energy Star® appliances that have power-saving measures installed.

Electricity Monitor– A device that monitors electricity use by appliances. It plugs into the electric outlet and the device plugs into the monitor which measures and displays how much electricity the device uses. Kill A Watt meter by P3 and Poniie PN1500 are the preferred electricity monitors.

Kilowatt (kW)– A unit used to measure power. One kilowatt equals 1,000 watts (W).

Kilowatt-hours (kWh)– A unit used to measure energy consumption. A kilowatt-hour is the amount of energy used if you use 1000 watts for one hour and is equivalent to 3.6 million joules or 3,412 BTUs.

Power – The rate at which work is performed or energy is converted; units of power include both an amount of energy and a length of time.

Watt (W) – A unit used to measure power. One watt equals one joule per second (j/s). A typical incandescent light bulb uses 60 W to keep the light bulb lit for one hour.

Wattage – Amount of power an electric appliance uses, measured in watts.

Gear Up:
  • Begin by asking students to estimate how much time they use certain appliance everyday. Start with common electronics like TV’s, gaming systems, computers, etc. Then ask them to think about the amount of time they use those things over a whole year.
  • Ask students to guess how much it costs to power these appliances every day? Then every year. Have an example calculation ready to show them how much it costs to power something in their community.
  • Discuss the method(s) of electrical production in your community and region. Does your electricity come from natural gas, hydro power, coal, diesel, or another energy resource?  Distribute the appropriate Calculating Cost worksheets and discuss the cost differences for different communities. Explore how the resources communities use to produce electricity has a big impact on the rates.
  • Optional: Use one of the the Be an Energy Star Powerpoints to cover the basics of calculating electricity costs before the lab or worksheet activities. If you are not in Anchorage or Kodiak you can adapt the presentation to reflect a place-based example from your community.
Activity:
  • Calculating Cost Lab: Divide students into small groups and have them record the electricity use of various appliances in the classroom/school (e.g.: computers, lamps, microwaves, coffee pots, etc.). You can measure electricity use using electricity monitors. If you do not have access to electricity monitors, you can use the wattage values found on the Energy Label sticker found on the bottom of many electronics. If no sticker exists, use the recommended websites in Additional Resources to research appliance wattages.
  • Alternatively, your class can do the Calculating Costs student worksheet. This worksheet does not require any setup/take down and works well with shorter class periods.

This video shows how to use the Poniie 1500 electricity monitor which is included in kits from REAP:

Extension:
  • Have students determine what variables impact energy costs (type of technology used in the community, climate, etc.) and write a paragraph explaining these variables. What are their thoughts on what type of energy should be produced in their community and how to reduce energy costs? What are some things that they can do to make a difference? 
  • Download the Energy Pledge Cards and have each students complete their own card, pledging to reduce their energy use through one efficiency and one conservation measure.
Evaluation:

Ask students to:

  • Identify the local community electricity cost, electricity supplier, and electricity production resource(s).
  • Complete and submit the student worksheet.