**Related Resources: Engineering Conversions Equivalent**

### Thermal Energy Quantities Units and Conversions

**Engineering Conversions and Equivalents**

Thermal Energy Quantities Units and Conversions

Where:

Length = L

Mass = M

Time = T

Current = Q/T

Charge = Q

*The dimension of temperature is θ; the unit is K°

#### Energy Units and Conversions

1 Joule (J) is the MKS unit of energy, equal to the force of one Newton acting through one meter.

1 Watt is the power of a Joule of energy per second

Power = Current x Voltage (P = I V)

1 Watt is the power from a current of 1 Ampere flowing through 1 Volt.

1 kilowatt is a thousand Watts.

1 kilowatt-hour is the energy of one kilowatt power flowing for one hour. (E = P t).

1 kilowatt-hour (kWh) = 3.6 x 10^{6} J = 3.6 million Joules

1 calorie of heat is the amount needed to raise 1 gram of water 1 degree Centigrade.

1 calorie (cal) = 4.184 J

(The Calories in food ratings are actually kilocalories.)

A BTU (British Thermal Unit) is the amount of heat necessary to raise one pound of water by 1 degree Farenheit (F).

1 British Thermal Unit (BTU) = 1055 J (The Mechanical Equivalent of Heat Relation)

1 BTU = 252 cal = 1.055 kJ

1 Quad = 10 15 BTU (World energy usage is about 300 Quads/year, US is about 100 Quads/year in 1996.)

1 therm = 100,000 BTU

1,000 kWh = 3.41 million BTU

#### Power Conversion

1 horsepower (hp) = 745.7 watts

#### Gas Volume to Energy Conversion

One thousand cubic feet of gas (Mcf) -> 1.027 million BTU = 1.083 billion J = 301 kWh

One therm = 100,000 BTU = 105.5 MJ = 29.3 kWh

1 Mcf -> 10.27 therms

#### Energy Content of Fuels

Coal 25 million BTU/ton

Crude Oil 5.6 million BTU/barrel

Oil 5.78 million BTU/barrel = 1700 kWh / barrel

Gasoline 5.6 million BTU/barrel (a barrel is 42 gallons) = 1.33 therms / gallon

Natural gas liquids 4.2 million BTU/barrel

Natural gas 1030 BTU/cubic foot

Wood 20 million BTU/cord

#### CO_{2} Pollution of Fossil Fuels

Pounds of CO_{2} per billion BTU of energy::

Coal 208,000 pounds

Oil 164,000 pounds

Natural Gas 117,000 pounds

Ratios of CO2 pollution:

Oil / Natural Gas = 1.40

Coal / Natural Gas = 1.78

Pounds of CO2 per 1,000 kWh, at 100% efficiency:

Coal 709 pounds

Oil 559 pounds

Natural Gas 399 pounds