Unit 1: What is Energy?

Section C. Measuring and Quantifying  Energy


 1. Conversion and Resource Tables

Energy Conversions

 British Thermal UnitFoot-
pounds
JoulescaloriesKilo-
calories
Kilowatt-
hours
1 British Thermal Unit1777.91055252.00.2522.93x10-4
1 Foot-pound0.00128511.3560.32383.238x10-43.766x10-7

1 joule
9.481x10-40.737610.23882.388x10-42.778x10-7

1 calorie
0.0039693.0884.18710.0011.163x10-6
1 kilocalorie
3.96930884187100010.001163
1 kilowatt hour34132.655x1063.6x1068.598x105859.81

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 secondHorse-
power
calories per secondKilo-
watts
Watts
1 foot-pound per second10.0018180.32380.0013561.356
1 horsepower
5501178.10.746746
1 Calorie per second3.0880.00561510.0041874.187

1 kilowatt
737.61.341238.811000

1 watt
0.73760.0013410.23880.0011

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
1 kilowatt hour of electricity=3413 British thermal units (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 CoalAverage Energy Content 
(Btu per lb.)
Carbon Content
(%)
Sulfur Content*
(%)
Known U.S. Reserves
(%)
Anthracite12,50086-980.4-1.91.5
Bituminous12,00050-860.8-5.051.0
Subbituminous9,00040-00.6-1.838.0
Lignite7,000401.69.5
* 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 WoodEnergy Content / Cord of Wood 
(MMBtu* / cord)
Energy Content / Pound of Wood 
(Btu / pound)
Weight / Cord of Air-Dried Wood 
(pounds / cord)
Ash20.05,8143,400
Aspen12.55,7872,160
Balsam Fir11.35,3812,100
Beech21.85,7983,760
Birch (Yellow)21.35,7883,680
Hickory (shagbark)24.65,8014,240
Maple (sugar)21.35,7883,680
Oak (white)22.75,7913,920
Pine (white)13.36,3942,080

*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
ApplianceAnnual kWh Consumption 
per Household
Central Air Conditioning2,667
Room Air Conditioning738
Water Heater2,671
Refrigerator1,155
Freezer1,204
Range / Oven458
Dishwasher299
Water Bed Heater960
Clothes Washer99
Clothes Dryer875

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 ApplianceWattage (Watts)Home ApplianceWattage (Watts)
Heating/CoolingLaundry/Utility
Dehumidifier645Iron1,000
Fans
   Ceiling
    20-24" Window
    Oscillating 

100
200
88
Vacuum Cleaner650
Portable Humidifier88Personal Care
Portable Space Heater1,500Blanket200
Water Bed Heater350Curling Iron40
Home Office and EntertainmentHair Dryer
    Blower
    Blower/Styler
    Hood-Type
    Soft Bonnet

1,200
600
1,200
400
Fish Aquarium
    Filter
    Heater
    Pump

10
100
10
Heating Pad50
Home Computer (Standard)150Shaver14
Printer
     Ink Jet
     Laser

19
175-275

Toothbrush (Electric)

7

Movie or Slide Projector150School EquipmentWattage (Watts)
Sewing Machine75Aquarium Pump4
Solid-State Radio15Aquarium Heater100
Stereo110Computer (Standard)150
Television
     Color
     Black & White 

200-350
40-160
PhotocopierUp to 2,500
Typewriter60Ditto Machine65
VCR40Electric TypewriterLess than 50
KitchenFilm Projector350
Blender400Filmstrip Projector500
Broiler1,500Filmstrip Viewer 7
Can Opener120Opaque Projector1,000
Coffee Maker1,400Overhead Projector500-850
Corn Popper
     Hot-Air Type
     Oil-Type

1,200
575
Printer
    Ink Jet
    Laser


19
175-275
Food Chopper360Record Player30-100
Food Processor360Slide Projector500
Frying Pan/Skillet1,300Tape Recorder6-100
Hot Plate1,100Television
     Black & White
     Color

40-160
200-350
Kettle1,500VCR40
Microwave Oven750

Mixer
    Hand
    Heavy-Duty

120
210


Toaster1,000

Toaster Over1,350

Waffle Maker1,200

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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