Unit 1: What is Energy?
Section C. Measuring and Quantifying Energy
|
1. Conversion and Resource Tables
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 | 2.93x10-4 |
| 1 Foot-pound | 0.001285 | 1 | 1.356 | 0.3238 | 3.238x10-4 | 3.766x10-7 |
1 joule
| 9.481x10-4 | 0.7376 | 1 | 0.2388 | 2.388x10-4 | 2.778x10-7 |
1 calorie
| 0.003969 | 3.088 | 4.187 | 1 | 0.001 | 1.163x10-6 |
1 kilocalorie
| 3.969 | 3088 | 4187 | 1000 | 1 | 0.001163 |
| 1 kilowatt hour | 3413 | 2.655x106 | 3.6x106 | 8.598x105 | 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 |
| 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 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) | Home Appliance | Wattage (Watts) |
| Heating/Cooling | Laundry/Utility |
| Dehumidifier | 645 | Iron | 1,000 |
Fans
Ceiling
20-24" Window
Oscillating |
100
200
88 | Vacuum Cleaner | 650 |
| Portable Humidifier | 88 | Personal Care |
| Portable Space Heater | 1,500 | Blanket | 200 |
| Water Bed Heater | 350 | Curling Iron | 40 |
| Home Office and Entertainment | Hair Dryer
Blower
Blower/Styler
Hood-Type
Soft Bonnet |
1,200
600
1,200
400 |
Fish Aquarium
Filter
Heater
Pump |
10
100
10 | Heating Pad | 50 |
| Home Computer (Standard) | 150 | Shaver | 14 |
Printer
Ink Jet
Laser |
19
175-275 | Toothbrush (Electric) | 7 |
| Movie or Slide Projector | 150 | School Equipment | Wattage (Watts) |
| Sewing Machine | 75 | Aquarium Pump | 4 |
| Solid-State Radio | 15 | Aquarium Heater | 100 |
| Stereo | 110 | Computer (Standard) | 150 |
Television
Color
Black & White |
200-350
40-160 | Photocopier | Up to 2,500 |
| Typewriter | 60 | Ditto Machine | 65 |
| VCR | 40 | Electric Typewriter | Less than 50 |
| Kitchen | Film Projector | 350 |
| Blender | 400 | Filmstrip Projector | 500 |
| Broiler | 1,500 | Filmstrip Viewer | 7 |
| Can Opener | 120 | Opaque Projector | 1,000 |
| Coffee Maker | 1,400 | Overhead Projector | 500-850 |
Corn Popper
Hot-Air Type
Oil-Type |
1,200
575 | Printer
Ink Jet
Laser |
19
175-275 |
| Food Chopper | 360 | Record Player | 30-100 |
| Food Processor | 360 | Slide Projector | 500 |
| Frying Pan/Skillet | 1,300 | Tape Recorder | 6-100 |
| Hot Plate | 1,100 | Television
Black & White
Color |
40-160
200-350 |
| Kettle | 1,500 | VCR | 40 |
| Microwave Oven | 750 |
|
|
Mixer
Hand
Heavy-Duty |
120
210 |
|
|
| Toaster | 1,000 |
|
|
| Toaster Over | 1,350 |
|
|
| Waffle Maker | 1,200 |
|
|
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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