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Energy Education:
Concepts & Practices

Unit 1: What is Energy?

Conversion & Resource Tables

Energy Conversions
Power Conversions
Conversion Factors
Measurement Conversions
Coal Types
Energy Content & Weight
US Household Averages
Wattages of Appliances
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Energy Conversions

  British Thermal Unit Foot-pounds Joules Calories Kilo-calories Kilowatt-hours
1 British Thermal Unit 1 777.9 1055 252.0 0.252 2.93×10-4
1 Foot-pound 0.001285 1 1.356 0.3238 3.238×10-4 3.766×10-7
1 Joule 9.481×10-4 0.7376 1 0.2388 2.388×10-4 2.778×10-7
1 Calorie 0.003969 3.088 4.187 1 0.001 1.163×10-6
1 Kilocalorie 3.969 3088 4187 1000 1 0.001163
1 Kilowatt hour 3413 2.655×106 3.6×106 8.598×105 859.8 1
Table adapted from “ELEMENTS OF PHYSICS 5/E. by SHORTLEY/WILLIAMS, 1971. Adapted by permission of Prentice-Hall, Inc., Upper Saddle River, N.J.

For example, this table shows that 1 kilowatt-hour (kWh) = 3413 British Thermal Units (Btu). If you were to convert 15 kWh to Btu, use the following calculation:

15 kWh x 3413 British Thermal Units = 51,195 Btu
                             1 kWh

Power Conversions

  Foot-pounds per second Horse-power Calories per second Kilo-watts Watts
1 Foot-pound per second 1 0.001818 0.3238 0.001356 1.356
1 Horsepower 550 1 178.1 0.746 746
1 Calorie per second 3.088 0.005615 1 0.004187 4.187
1 Kilowatt 737.6 1.341 238.8 1 1000
1 Watt 0.7376 0.001341 0.2388 0.001 1

For example, this table shows that 1 watt = 0.001341 horsepower. If you were to convert 250 watts to horsepower, use the following calculation:

250 watts x 0.001341 horsepower = 0.34 horsepower
                             1 watt

Conversion Factors

Average Energy Content of Various Fuels
(Measured in British Thermal Units – Btu)

1 kilowatt hour of electricity = 3413 (Btu)
1 cubic foot of natural gas = 1,008 to 1,034 Btu
1 therm of natural gas = 100,000 Btu
1 gallon of crude oil = 138,095 Btu
1 barrel of crude oil = 5,800,000 Btu
1 gallon of residual fuel oil = 149,690 Btu
1 gallon of gasoline = 125,000 Btu
1 gallon of ethanol = 84,400 Btu
1 gallon methanol = 62,800 Btu
1 gallon of gasohol (10% ethanol, 90% gasoline) = 120,900 Btu
1 gallon of E-85 (85% ethanol, 15% gasoline) = 90,500 Btu
1 gallon of kerosene or light distillate oil = 135,000 Btu
1 gallon of middle distillate or diesel fuel oil = 138,690 Btu
1 gallon of liquefied petroleum gas (LPG) = 95,475 Btu
1 pound of coal = 8,100 to 13,000 Btu
1 ton coal = 16,200,000 to 26,000,000 Btu
1 ton wood = 9,000,000 to 17,000,000 Btu
1 standard cord of wood = 18,000,000 to 24,000,000 Btu
1 face cord of wood = 6,000,000 to 8,000,000 Btu
1 pound of low pressure steam (recoverable heat) = 1,000 Btu

Measurement Conversions

1 short ton (ton) = 2,000 pounds = 6.65 barrels (crude oil)
1 metric ton (tonn) = 2,200 pounds
1 barrel (bbl) = 42 gallons = 5.615 cubic feet = 159.0 liters
1 therm = 105 Btu = 100,000 Btu
1 thousand Btu (kBtu) = 1,000 Btu
1 million Btu (MMBtu) = 1,000,000 Btu
1 quad = 1 quadrillion Btu = 1015 Btu = 1,000,000,000 MMBtu
1 kilowatt-hour (kWh) = 1,000 watt-hours
1 megawatt-hour (MWh) = 1,000 kWh or 1,000,000 watt-hours
1 gigawatt-hour (GWh) = 1,000 MWh or 1,000,000,000 watt-hours
1 standard cord of wood = 8 feet x 4 feet x 4 feet = 128 cubic feet = approximately 4,000 pounds
1 face cord of wood = 8 feet x 4 feet x 16 inches = 42.7 cubic feet = approximately 1,333 pounds

Coal Types

Type of Coal Average Energy Content (Btu per lb.) Carbon Content (%) Sulfur Content * (%) Known U.S. Reserves (%)
Anthracite 12,500 86-98 0.4-1.9 1.5
Bituminous 12,000 50-86 0.8-5.0 51.0
Subbituminous 9,000 40-0 0.6-1.8 38.0
Lignite 7,000 40 1.6 9.5
* For selected samples of coal types. Numbers may not cover the compete range of sulfur contained in a given type of coal.
Adapted from U.S. Department of Energy, Energy Information Administration, Office of Coal, Nuclear, Electric, and Alternative Fuels. Coal Data: A Reference: Washington, D.C. 1995.

Energy Content and Weight per Cord of 
Certain Types of Wood Found in Wisconsin

Type of Wood Energy Content / Cord of Wood (MMBtu* / cord) Energy Content / Pound of Wood (Btu / pound) Weight / Cord of Air-Dried Wood (pounds / cord)
Ash 20.0 5,814 3,400
Aspen 12.5 5,787 2,160
Balsam Fir 11.3 5,381 2,100
Beech 21.8 5,798 3,760
Birch (Yellow) 21.3 5,788 3,680
Hickory (shagbark) 24.6 5,801 4,240
Maple (sugar) 21.3 5,788 3,680
Oak (white) 22.7 5,791 3,920
Pine (white) 13.3 6,394 2,080
*1 MMBtu = 1,000,000 Btu
Adapted from Solar Energy Project “Heating Value of Wood” p. 2-13 in “Wood: Stored Solar Energy.” Renewable Energy Activities for Biology. Albany, N.Y.: Solar Energy Project, State University of New York at Albany, n.d., and Wisconsin Department of Natural Resources, Bureau of Forestry. Forest Trees of Wisconsin: How to Know Them. Madison, Wisc., 1990. PUBL-FR-053 90REV.

Average U.S. Household Electric Consumption for Major Electrical Appliances

Appliance Annual kWh Consumption per Household
Central Air Conditioning 2,667
Room Air Conditioning 738
Water Heater 2,671
Refrigerator 1,155
Freezer 1,204
Range / Oven 458
Dishwasher 299
Water Bed Heater 960
Clothes Washer 99
Clothes Dryer 875
From Lawrence Berkeley National Laboratory. “Standby Consumption Values for Residential Appliances,” table. Internet. Leaking Electricity Home Page: eetd.lbl.gov/leaking. 1998.
Want to calculate your appliance energy use? Check out the U.S. Department of Energy’s Appliance Energy Calculator.

Wattages of Small- and Medium-Sized Electrical Appliances
and Equipment Found in Homes and Schools

Home Appliance

Wattage (Watts)
Heating/Cooling
Dehumidifier 645
Portable Humidifier 88
Portable Space Heater 1,500
Water Bed Heater 350
Fans
Ceiling 100
20-24″ Window 200
Oscillating 88
Home Office and Entertainment
Home Computer (Standard) 150
Movie or Slide Projector 150
Sewing Machine 75
Solid-State Radio 15
Stereo 110
Typewriter 60
VCR 40
Fish Aquarium
Filter 10
Heater 100
Pump 10
Printer
Ink Jet 19
Laser 175-275
Television
Color 200-350
Black & White 40-160
Laundry/Utility
Iron 1,000
Vacuum Cleaner 650

Home Appliance

Wattage (Watts)
Kitchen
Blender 400
Broiler 1,500
Can Opener 120
Coffee Maker 1,400
Food Chopper 360
Food Processor 360
Frying Pan/Skillet 1,300
Hot Plate 1,100
Kettle 1,500
Microwave Oven 750
Toaster 1,000
Toaster Oven 1,350
Waffle Maker 1,200
Corn popper
Hot-Air Type 1,200
Oil Type 575
Mixer
Hand 120
Heavy-Duty 210
Personal Care
Blanket 200
Curling Iron 40
Heating Pad 50
Shaver 14
Toothbrush (Electric) 7
Hair Dryer
Blower 1,200
Blower/Styler 600
Hood-Type 1,200
Soft Bonnet 400

School Equipment

Wattage (Watts)
Aquarium Pump 4
Aquarium Heater 100
Computer (Standard) 150
Photocopier Up to 2,500
Ditto Machine 65
Electric Typewriter Less than 50
Film Projector 350
Filmstrip Projector 500
Filmstrip Viewer 7
Opaque Projector 1,000
Overhead Projector 500-850
Record Player 30-100
Slide Projector 500
Tape Recorder 6-100
VCR 40
Printers
Ink Jet 19
Laser 175-275
Television
Black & White 40-160
Color 200-350
Society, Environment & Energy Development Studies Foundation: SEEDS 5: The Energy Literacy Series. p. 38. Edmonton, Alberta: Society, Environment & Energy Development Studies Foundation, 1981.

Wisconsin Public Service Corporation. Appliance Energy Cents. 157-1035 8/95. Green Bay, Wisc.: Wisconsin Public Service Corporation, August, 1995.

Madison Gas and Electric Co. Appliance Energy Costs. Madison, Wisc.: Madison Gas and Electric Co., 1996.
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