As defined in the Energy Security Act (P.L. 96-294; 1980) as "any organic matter, including sewage, sewage sludge, and industrial or commercial waste, and mixtures of such matter and inorganic refuse from any publicly or privately operated municipal waste ...

Ratio of useful energy output of a device to the energy input, averaged over an entire heating season.

The conversion of the complex carbohydrates in organic material into energy.

A type of impulse hydropower turbine where water passes through nozzles and strikes cups arranged on the periphery of a runner, or wheel, which causes the runner to rotate, producing mechanical energy. The runner is fixed on a shaft, and the rotational mo ...

A unit of heat containing 100,000 British thermal units (Btu).

A pump for circulating the heat transfer fluid in a hydronic heating system.

The overall rate of heat loss from a building by means of transmission plus infiltration, expressed in Btu per hour, per degree temperature difference between the inside and outside.

Energy produced by the internal heat of the earth; geothermal heat sources include: hydrothermal convective systems; pressurized water reservoirs; hot dry rocks; manual gradients; and magma. Geothermal energy can be used directly for heating or to produce ...

The cutting of a grid pattern of grooves in a semiconductor material, generally for the purpose of making interconnections.

Draft that is caused by temperature differences in the air.

The maximum possible voltage across a photovoltaic cell; the voltage across the cell in sunlight when no current is flowing.

A generic term for a glazed opening that allows daylight to enter into a building and can be opened for ventilation.

An abbreviation for one thousand cubic feet of natural gas with a heat content of 1,000,000 Btus, or 10 therms.

A metric unit of energy or work; the energy produced by a force of one Newton operating through a distance of one meter; 1 Joule per second equals 1 Watt or 0.737 foot-pounds; 1 Btu equals 1,055 Joules.

The downward facing structural element that is directly opposite the floor.

A group of organic compounds composed of carbon, hydrogen, and oxygen; a series of molecules composed of a hydrocarbon plus a hydroxyl group; includes methanol, ethanol, isopropyl alcohol and others.

The complex process by which organic matter is decomposed by anaerobic bacteria. The decomposition process produces a gaseous byproduct often called "biogas" primarily composed of methane, carbon dioxide, and hydrogen sulfide.

Any light source designed specifically to direct light a task or work performed by a person or machine.

A total life cycle cost divided into equal amounts.

A method for making sheets of polycrystalline silicon in which silicon dendrites are slowly withdrawn from a melt of silicon whereupon a web of silicon forms between the dendrites and solidifies as it rises from the melt and cools.