Energy Hour
Appliance Inventory
Check off the appliances and electronic devices that you have in your apartment and then add up the total energy
usage using the average wattages we provided for each appliance. Use the Reference Table provided in the box to
easily determine the total watt-hours for each appliance based on hourly usage. Next, calculate the cost per month,
which is based on the average cost of electricity - 12¢ per kWh. Since a kilowatt is 1000 watts, you first need to divide
your watt-hours by 1000. Add the totals from each section to see your total costs per month.
What’s Cookin’?
Electric Kettle
Microwave
Toaster/ Toaster Oven
Coffee Maker
Electric Stove
Blender and/or Hand Mixer
Mini Fridge
1600 W *
1125 W *
1100 W *
1050 W *
1000 W *
210 W *
33 W *
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
168 hours/week
Subtotal
=
=
=
=
=
=
=
=
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours ÷ 1000 W/kW
* 4.3 weeks/month
* $0.12/kWh =
Game Time
Desktop with Monitor
50” LCD TV
27” LCD TV
Video Game Console
Laptop
DVR/ DVD Player
Tablet
300 W *
266 W *
127W *
120W *
75 W *
50 W *
10 W *
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
Subtotal
=
=
=
=
=
=
=
=
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours ÷ 1000 W/kW
* 4.3 weeks/month
* $0.12/kWh =
Weather Report
Space Heater
Central A/C
A/C Unit: Large size
A/C Unit: Medium size
A/C Unit: Small size
Box Fan
Ceiling Fan
Humidifier
Oscillating Fan
1125 W *
3500 W *
1440 W *
900 W *
500 W *
140 W *
120 W *
75 W *
50 W *
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
hours/week
Subtotal
=
=
=
=
=
=
=
=
=
=
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours ÷ 1000 W/kW
* 4.3 weeks/month
* $0.12/kWh =
Cleanin’ Up
Hair Dryer
Clothes Iron
Vacuum Cleaner
Straightening Iron
1540 W *
1400 W *
1045 W *
1100 W *
hours/week
hours/week
hours/week
hours/week
Subtotal
=
=
=
=
=
watt-hours
watt-hours
watt-hours
watt-hours
watt-hours ÷ 1000 W/kW
* 4.3 weeks/month
* $0.12/kWh =
Total =
Energy Hour
Appliance Inventory
Discussion Questions
1. What type of activity uses the most energy? What was the most surprising energy user? Least surprising?
2. Can you identify ways to cut energy use in each section?
What’s Cookin’?:
Game Time:
Weather Report:
Cleanin’ Up:
3. How many of your appliances have a box attached to their electrical cord or have lights that are kept on
even if the appliance is off?
These appliances pull phantom loads (also known as vampire energy), meaning they use electricity
continuously, even when they are off or not in use. Phantom loads use between 0.5 and 5 W.
If all Ann Arbor renters unplugged these appliances, they would save almost $300,000 in electricity costs
per year! To save money and energy, remember to unplug any appliance that pulls a phantom load.
INCANDESCENT LIGHT BULB
1,200 HOURS OF LIGHT
800 LUMENS
60 WATTS
$0.38 per bulb
light through incandescence/
thermal radiation/this bulb
emits light through heat/
just 10% of energy used is
converted into light
COMPACT FLORESCENT LAMP
(CFL)
10,000 HOURS OF LIGHT
800 LUMENS
14 WATTS
$1.90 per bulb
light through florescence/an
electric current causes mercury
vapor to produce ultraviolet
light/ultraviolet light makes the
tube’s florescent coating glow
LIGHT EMITTING DIODE
(LED)
50,000 HOURS OF LIGHT
800 LUMENS
10 WATTS
$9.97 per bulb
light through
electroluminescene/two-lead
semiconductor light source/a
voltage causes electrons to
release energy as photons
50,000 HOURS OF LIGHT
50,000 HOURS OF LIGHT
50,000 HOURS OF LIGHT
42 bulbs (at $0.38/bulb) +
(3,000 kWh * $.12) = $375.96
5 bulbs (at $1.90/bulb) +
(700 kWh * $.12) = $93.50
1 bulb (at $9.97/bulb) +
(500 kWh * $.12) = $69.97
1,064 lbs of CO2 emissions
equivalent of 1,149 miles driven
760 lbs of CO2 emissions
equivalent of 821 miles driven
4,561 lbs of CO2 emissions
equivalent of 4,925 miles driven