Electricity

A lesson plan for Middle school utilizing Microsoft Excel

It’s electricBoogie Woogie

• What is electricity?

• How do we create electricity?

How much money does it cost to run a computer for 24 hours?

• Open the file called electricity on the hard drive of your computer.

• Middle SchoolAppliance Hours/Day Used Wattage Watt Hours Kilowatt Hours Cost

TV 19 inch Color 60Refrigerator 490

Incandescent Light 75Electric Clock 12Clock Radio 10

Stereo 15Computer 80

Dishwasher 1500Washing Machine 450

Dryer 250Total

• After we fill in the “hours per day used” column.

• We see column C has been filled in already and marked wattage.

• What is wattage?

Wattage

• The measure of the amount of power used

• In this case by each appliance

Watt Hours

• If wattage is

• The measure of the amount of power used

• Then what are watt hours?

Watt hours

• The wattages listed on the chart are

• For one hour

• Therefore

• How would we find watt hours?

• Taking Watts times hours will give us watt hours.

• =C2*B2

Kilowatt hours

• What is a kilowatt?

• 1000 watts

• How do we find kilowatt hours?

• Watt hours divided by 1000

• =D2/1000

• Your parents probably don’t care how many kilowatt hours you use.

• You have probably never been yelled at for using too many kilowatt hours.

• What your parents do care about is the cost of that electricity usage.

• The electric company charges you per kilowatt hour of power you use.

Guess

• How much does one kilowatt hour of power cost?

• $0.08275

• Just over eight cents per kilowatt hour

• So to find out how much money these appliances cost per day, we multiply kilowatt hours times 0.08275

• =E2*0.08275

• We are going to copy these good formulas all the way down the columns.

• We need to use the sigma to find the totals for each column.

• The total money spent on electricity comes out to about $1.00 per day

• Is this right?

• Why not?

• We have many more appliances to list than those first 10.

• Delete the entire total line

• Then you will need to list all of the other appliances that use electricity in your home.

• The wattages can be found in a file marked “Wattages of Common Appliances” on your Hard Drive.

ApplianceWatts Appliance Watts Appliance Watts

Coffee pot 200 Garage door opener 350 Electric mower 1500

Coffee maker 1000 Table fan 10-25 Hedge trimmer 450

Toaster 1200 Ceiling fan 10-50 Weed eater 500

Popcorn popper 250 Electric Blanket 300 1/4" drill 250

Blender 300 Blow dryer 1000 1/2" drill 750

Microwave (.5 cu. ft.) 900 Shaver 15 1" drill 1000

Microwave (.8 to 1.5 cu ft)

1500 laptop computer 25 9" disk sander 1200

Hot plate 1200 desktop computer 55 3" belt sander 1000

Frying pan 1200 laser printer 900 12" chain saw 1100

Dishwasher (cool dry) 700 Ink jet printer 35 14" band saw 1100

Dishwasher (hot dry) 1450 25" color TV 150Refrigerator (4yrs old, 22 cu ft)

500

Washing machine (vertical axis)

900 19" color TV 70Refrigerator (new, 22 cu ft)

200

Washing machine (horizontal axis)

250 12" b&w TV 20 Sink garbage disposal 450

Vacuum (handheld) 100 VCR 40 Trash compactor 1500

Vacuum (upright) 700 CD player 35 electric can opener 100

Iron 1000 AC stereo/ home theater 500 Food processor 400

Clothes dryer (electric) 4000 Clock radio 1 Food dehydrator 600

• Once you fill in:

• the name of the appliances,

• the hours per day that they are used

• their wattages from the chart

• you can calculate the other columns using copy and paste to copy the formulas we typed earlier.

Replace the total

• We need to find the total for each column now that they are much expanded.

• How do we do that?

• We need to use the sigma to find the totals for each column.

• After you have found the total cost for one day’s electricity

• Find the total cost for one month and one year.

• Then write a sentence:

• “We currently spend xxxxxxxx on electricity in one year.”

• Then make changes to your usage to reduce the total cost.

• Keep track of what appliances you change.

• See how the total cost is effected.

• Then write a second sentence:• “If we _____________ then we can reduce

the cost of our electricity by more than $100 per year.”

• Hand in your completed spreadsheet document through the student information system