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Title: Coal To Electricity
Level: Middle School
Time: 40 minutes
KERA Goals: 1.9; 2.13; 2.4

Objective:

Over 56 percent of the electricity in U.S. is generated from coal.   In fact, more than 84 percent of the coal consumed each year in the U.S. is used to generate electricity.  It takes about one pound of coal to generate one kilowatt hour (kwh) of electricity.



Electric Appliance

Average Wattage

Average Kilowatts

Estimated Pounds of
Coal Consumed
Annually

Dishwasher 1,201 1.20 363
Microwave 1,450 1.45 190
Range 12,200 12.20 730
Clothes Dryer 4,856 4.86 993
Iron 1,100 1.10 60
Washing Machine 512 0.51 103
Refrigerators/Freezers 2,250 2.25 1,500
Hair Dryer 600 0.60 25
B/W Television 45 0.05 100
Color Television 145 0.14 320
Clock 2 0.01 320
Vacuum Cleaner 630 0.63 46

Materials:

Graph paper
Colored pens
Copy of "Coal to Electricity" table

Questions:

  1. Construct a bar graph that indicates the amount of coal required to run each of the following appliances for one hour.

    dishwasher clothes dryer
    microwave water heater
    range color TV

  2. How many pounds of coal would be needed to operate a color TV for 8 hours?  16 hours? 24 hours?

  3. How many hours of electricity annually do the following appliances consume based upon the "Coal to Electricity" table?  Color TV?  Water Heater?  Dishwasher?  Clock?

  4. How much more coal is needed to run a color TV for one hour than to run a B/W TV?

  5. A 100 watt light bulb uses 1 kw of electricity per hour.  How many pounds of coal are needed to run one 100 watt light bulb for 6 hours?  8 hours?   10 hours?

Answers:

  1. Answers will vary.
  2. Eight hours = 1.12 pounds, 16 hours = 2.24 pounds, 24 hours = 3.36 pounds
  3. Color TV = 320 kwh, water heater = 4,219 kwh, dishwasher = 363 kwh, clock = 320 kwh
  4. 0.09 pounds per hour
  5. Six hours = 0.6 pounds, eight hours = 0.8 pounds, ten hours = 1 pound 

Provided by National Energy Foundation.