Conserving
Electricity

Print
out the table below and fill in the numbers and calculations
that follow. For each of the appliances listed below you will
need to look on that appliance and find its power rating in
watts. You will also need to find out how much your energy
utility or company charges you for your electricity. Then
estimate how many hours that you use each appliance in a year.
Finally, from this information, you can calculate for each
appliance the energy use in kwatt hr/year and cost in $/yr.
A set of sample calculations and some websites to help you
out are given below the table.

Energy Inventory

Cost
of Electricity: $ / kwatt hr = ___________ 
# 
Item 
Power
(kwatts) 
Estimated
Time
(hr/yr) 
Energy
Use
(kwatt hr/yr) 
Cost
($/yr) 
1 
Toaster 
. 
. 
. 
. 
2 
Oven 
. 
. 
. 
. 
3 
Incandescent
Lamp 
. 
. 
. 
. 
4 
Fluorescent
Lamp 
. 
. 
. 
. 
5 
Television 
. 
. 
. 
. 
6 
Computer 
. 
. 
. 
. 
7 
Video
Games (no TV) 
. 
. 
. 
. 
8 
Hair
Dryer 
. 
. 
. 
. 
9 
Clothes
Washer 
. 
. 
. 
. 
10 
Clothes
Dryer 
. 
. 
. 
. 
11 
Table
Fan 
. 
. 
. 
. 
12 
Hot
Water Heater 
. 
. 
. 
. 
13 
Food
Blender 
. 
. 
. 
. 
14 
Clock 
. 
. 
. 
. 
15 
Vacuum
Cleaner 
. 
. 
. 
. 
16 
Space
Heater 
. 
. 
. 
. 
17 
Clock
Radio 
. 
. 
. 
. 
18 
Stereo
(Amplifier) 
. 
. 
. 
. 
19 
CD
Player 
. 
. 
. 
. 
20 
Power
Drill 
. 
. 
. 
. 
21 
Torchiere
Lamp 
. 
. 
. 
. 
22 
Coffee
Pot 
. 
. 
. 
. 
23 
Refrigerator 
. 
. 
. 
. 
24 
Cordless
Phone 
. 
. 
. 
. 
25 
Electric
Blanket 
. 
. 
. 
. 
26 
Air
Conditioner 
. 
. 
. 
. 
27 
Dishwasher 
. 
. 
. 
. 
28 
Microwave
Oven 
. 
. 
. 
. 
29 
Small
Freezer 
. 
. 
. 
. 
30 
. 
. 
. 
. 
. 
Sample
Calculations
Let's
say that you found that your microwave oven has a power rating of
120 watts. To convert that into kilowatts you must divide by 1000
as follows. Place this number in the table.
You
estimate that your microwave oven is used 3 hours per day. Multiply
by 365 days per year to get the hours used per year as follows:
Now
you can calculate your energy consumption by multiplying the power
in kw times the time used in hr/yr as follows:
\
Finally,
we can multiply the energy used in kw hr / yr by the cost in $ /
kw hr to get the actual cost in $ / yr as follows:
You
may need to do a search on the internet or look at your electricity
bill to find the cost per kw hr. The calculated numbers are shown
in the sample table below.
Cost
of Electricity: $ / kwatt hr = ___0.077__ 
# 
Item 
Power
(kwatts) 
Estimated
Time
(hr/yr) 
Energy
Use
(kwatt hr/yr) 
Cost
($/yr)

28 
Microwave
Oven 
0.120

1095

131.4.

10.12.

For
more information on calculating your energy costs, check out the
websites below.
