Energy Concepts and Terms
This page includes a quick orientation to common energy concepts and terms.
Energy and Power
Power = Energy/Time
- Power is Energy per unit time.
- Energy is related to power as gallons are related to gallons per minute.
ENERGY AND POWER TERMS
- British Thermal Unit (Btu) - A Btu is the amount of energy required to raise the temperature of one pound of water 1 degree Fahrenheit.
- Therm = 100,000 Btu, heat energy sources such as natural gas and steam may be sold in therms.
- Kilowatt (kW) – A measure of power equal to 1,000 watts. Also equal to 3,412 Btu/hr.
- Kilowatt-hour (kWh) - A kilowatt-hour is the quantity of energy delivered when power flows at the rate of one kilowatt for one hour. It is equal to 3,412 Btu.
- Cooling Ton - A cooling ton is 12,000 Btu/hr. It is the rate of cooling required to produce one ton of ice in a 24 hour period. The capacity of most air conditioning systems are expressed in tons.
How Much Energy is In?...
|Energy Source||Energy Content (Btu)||Units|
|Sunlight||200 Btu||per hour per square foot|
|Wind||75 Btu||per hour per square foot of wind turbine swept area in 22 mile per hour wind.|
|Biomass||7,000 Btu||per pound (value is for switchgrass)|
|Wood||8,000-10,000 Btu||per pound|
|Coal (Anthracite)||14,000-15,000 Btu||per pound|
|Coal (Bituminous)||10,500-14,000 Btu||per pound|
|Oil (#2 Fuel)||137,000-141,800 Btu||per gallon|
|Natural Gas||950-1,150 Btu||per cubic foot|
|Gasoline||109,000-125,000 Btu||per gallon|
|Kerosene||130,000-140,000 Btu||per gallon|
|Nuclear Fuel (Uranium)||35,000,000,000 Btu||per pound Uranium-235|