Click here for a printable version

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

Dishwasher1,2011.20363
Microwave1,4501.45190
Range12,20012.20730
Clothes Dryer4,8564.86993
Iron1,1001.1060
Washing Machine5120.51103
Refrigerators/Freezers2,2502.251,500
Hair Dryer6000.6025
B/W Television450.05100
Color Television1450.14320
Clock 20.01320
Vacuum Cleaner6300.6346

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.

    dishwasherclothes dryer
    microwavewater heater
    rangecolor 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.