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Physical Data

Based on:

Rough Values of Power of Various Processes (watts)

Solar power in all directions1027
Solar power incident on earth1017
Solar power avg. on U.S.1015
Solar power consumed in photosynthesis 1014
U.S. power consumption rate1013
U.S. electrical power1012
Large electrical generating plant109
Automobile at 40 mph105
Solar power on roof of U.S. home104
U.S. citizen consumption rate104
Electric stove104
Solar power per m2 on U.S. surface 102
One light bulb102
Food consumption rate per capita U.S.102
Electric razor101

Energy Content of Fuels (in Joules)

Energy Unit
Joules Equivalent (S.I.)
gallon of gasoline 1.3x108
AA battery103
standard cubic foot of natural gas (SCF) 1.1x106
candy bar106
barrel of crude oil (contains 42 gallons) 6.1x109
pound of coal1.6 x 107
pound of gasoline2.2 x 107
pound of oil2.4 x 107
pound of Uranium-235 3.7 x 1013
ton of coal3.2 x 1010
ton of Uranium-235 7.4 x 1016

Energy Conversions

Energy Unit
1 Btu1055 joules or778 ft­lb or252 cal
1 calorie4.184 joules
1 food Calorie1000 calories or
1 kilocalorie
1 hp­hr2.68 106 joules or0.746 kwh
1 kwh3.61106 joules or3413 Btu
1 eV1.610-19 joules

Fuel Requirements for a 1000­MWe Power Plant

(2.4 1011 Btu/day energy input)

Coal: 9000 tons/day of 1 "unit train load" (100 90 - ton cars/day)

Oil: 40,000 bbl/day or 1 tanker per week (note: "bbl" means barrels)

Natural Gas: 2.4 l08 SCF/day

Uranium (as 235U): 3 kg/day

Note: 1000 MWe utility, at 60% load factor, generates 5.3109 kwh/year, enough for a city of about 1 million people in the U.S.A.

(Note: MWE is an abbreviation for megawatts-electrical output)

Geographic Energy Needs

U.S. Total Energy Consumption (1990)

= 82.11015 Btu (82.1 Quads) = 38.8 MBPD oil equivalent = 86.6109 GJ

Everyday Usage and Energy Equivalencies

1 barrel of oil = driving 1400 km (840 miles) in average car

1 kwh electricity

= 1½ hours of operation of standard air conditioner

= 92 days for electric clock

= 24 hours for color TV

One million Btu equals approximately

90 pounds of coal

125 pounds of oven­dried wood

8 gallons of motor gasoline

10 therms of natural gas

1.1 day energy consumption per capita in the U.S.

Power Tables

Power is the amount of energy used per unit time - or how fast energy is being used. If we multiply a unit of power by a unit of time, the result is a unit of energy. Example: kilowatt-hour.

Power Conversions

1 watt1 joule/s or3.41 Btu/hr
1 hp or2545 Btu/hr or746 watts

Power Converted to Watts

1 Btu per hour0.293 W
1 joule per second 1 W
1 kilowatt-hour per day 41.7 W
1 food Calorie per minute 69.77 W
1 horsepower745.7 W
1 kilowatt1000 W
1 Btu per second1054 W
1 gallon of gasoline per hour 39 kW
1 million barrels of oil per day 73 GW

Rough Values of the Energies of Various Occurrences

Energy (J)
Creation of the Universe 1068
Emission from a radio galaxy 1055
E = mc2 of the Sun 1047
Supernova explosion 1044
Yearly solar emission 1034
Earth moving in orbit 1033
D-D fusion energy possible from worlds oceans 1031
Earth spinning1029
Earth's annual sunshine 1025
Cretaceous-Tertiary extinction theory meteorite 1023
Energy available from earth's fossil fuels 1023
Yearly U.S. sunshine 1023
Annual tidal friction 1020
U.S. energy consumption 1020
Exploding volcano (Krakatoa) 1019
Severe earthquake (Richter 8) 1018
100-megaton H-bomb 1017
Fission one ton of Uranium 1017
E = mc2 of 1 kilogram 1017
Burning a million tons of coal 1016
Energy to create Meteor Crater in Arizona 1016
1000-MW power station (1 year) 1016
Atomic Bomb (Hiroshima) 1014
E = mc2 of 1 gram 1014
Energy to put the space shuttle in orbit 1013
Energy used in one year per capita U.S. 1012
Atlantic crossing (one way) of jet airliner 1012
Saturn V rocket 1011
Energy to heat a house for one year 1011
D-D fusion energy possible from 1 gal. of water 1011
One year of electricity for the average house 1010
Lightening bolt1010
Burning a cord of wood 1010
One gallon of gasoline 108
100-W light bulb left on for one day 107
Human daily diet107
One day of heavy manual labor 107
Explosion of 1 kg of TNT 106
Woman running for 1 hr 106
Candy bar106
Burning match103
1AA battery (alkaline) 103
Hard-hit baseball103
Lifting an apple 1 m 1
Human heartbeat0.5
Depressing typewriter key 10-2
Cricket chirrup10-3
Hopping flea10-7
Proton accelerated to high energy (one trillion eV) 10-7
Fission of 1 uranium nucleus 10-11
Energy released in D-D fusion 10-12
Electron mass-energy 10-13
Chemical reaction per atom 10-18
Photon of light10-19
Energy of room-temperature air molecule 10-21

Cost of Various Fuels

Electricity1 Kwh $0.10 appliances, motors
Gasoline1 gallon 1.20 transportation
Natural Gas1 Therm 0.60 heating
AA battery1 battery 0.80 portable electronics
Milky Way candy bar 1 bar0.60 food

Worldwide Power Use-History

"Developed" countries average (1990):

  • 1.2 billion people 7.5 kilowatts/per person = 9.0 terawatts

The rest of the world (1990):

  • 4.1 billion people 1.1 kilowatts/person = 4.5 terawatts

World Population (est.)
(billion persons)
Average Power Use