This page includes a quick orientation to common energy concepts and terms.

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?...