A grid code is a technical specification which defines the parameters a facility connected to a public electric grid has to meet to ensure safe, secure and economic proper functioning of the electric system.

A greenhouse gas (sometimes abbreviated GHG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect.

Greenhouse gas emissions are emissions of greenhouse gases created from a range of human activities that cause climate change.

The langley (Ly) is a unit of heat transmission, especially used to express the rate of solar radiation (or insolation) received by the earth.

Landfill gas utilization is a process of gathering, processing, and treating the methane or another gas emitted from decomposing garbage to produce electricity, heat, fuels, and various chemical compounds. After fossil fuel and agriculture, landfill gas is the third largest human generated source of methane.

Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gases have an influence on climate change.

In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing.

A laddermill kite system is an airborne wind turbine consisting of a long string or loop of power kites.

A labyrinth seal is a type of mechanical seal that provides a tortuous path to help prevent leakage.

A laboratory is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed.

A kytoon or kite balloon is a tethered aircraft which obtains some of its lift dynamically as a heavier-than-air kite and the rest aerostatically as a lighter-than-air balloon.

The Kyoto Protocol is an international treaty which extends the 1992 United Nations Framework Convention on Climate Change (UNFCCC) that commits state parties to reduce greenhouse gas emissions, based on the scientific consensus that global warming is occurring and that human-made CO2 emissions are driving it

The ability of a fuel or fuel/air mixture to prevent engine knocking. Fuel octane rating can be

A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces.

Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits.

Kinetic friction is the friction between moving surfaces.

In physics, the kinetic energy of an object is the energy that it possesses due to its motion.

The measure of kilowatts used continuously for 1 hour.

A unit of power equivalent to 1,000 watts.

A kilogram-force per centimetre square (kgf/cm2), often just kilogram per square centimetre (kg/cm2), or kilopond per centimetre square is a deprecated unit of pressure using metric units.