Glossary: J to L
A-C | D-F | G-I | J-L | M-O | P-R | S-U | V-Z
J
Joule (J): A unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second (synonymous with watt-second).
K
Kilowatt (kW): A standard unit of electrical power equal to 1000 watts. The term “kilowatt” (in addition to the measurements of “watt” and “megawatt”) is commonly used to describe the capacity of an electric generator, particularly in reference to small solar photovoltaic and other generating systems.
Kilowatt-hour (kWh): 1,000 watts or 1 kilowatt acting over a period of 1 hour. One kilowatt-hour is equal to 1,000 watt-hours and is equal to 3600 kJ. The primary difference between a kilowatt and a kilowatt-hour is that “kilowatt” measures the capacity of an electric generator and “kilowatt-hour” measures the actual amount of electricity it produces over a certain period of time.
Kinetic energy: Kinetic energy is the release of potential energy to create motion, ultimately to do work. An example of kinetic energy is the energy carried by wind.
L
Landfill gas: Landfill gas is created when food, wood, and other organic waste in a landfill decomposes under anaerobic – or oxygen-free – conditions. Because landfill gas is about 50 percent methane, it can be used as a source of energy similar to natural gas (which is about 90% methane). Carbon dioxide (CO2) is the other primary component of landfill gas. Since landfill gas is generated continuously, it provides a reliable fuel for a range of energy applications, including heating and electric power generation. Learn more about landfill gas.