A plot of a wind energy conversion device's power output versus wind speed.

The air that is supplied to the combustion chamber of a furnace.

A window located on the roof of a structure to provide interior building spaces with natural daylight, warmth, and ventilation.

Wind turbines that operate at a constant rotor revolutions per minute (RPM) and are optimized for energy capture at a given rotor diameter at a particular speed in the wind power curve.

A turbine that has a runner with attached blades similar to a propeller used to drive a ship. As water passes over the curved propeller blades, it causes rotation of the shaft.

A deposition process whereby heat is used to break molecules into elemental sources that are then spray deposited on a substrate.

That portion of an electricity supply system used to deliver electricity from points on the transmission system to consumers.

A measure of light quality. The maximum CRI value of 100 is given to natural daylight and incandescent lighting. The closer a lamp's CRI rating is to 100, the better its ability to show true colors to the human eye.

The power required to energize the magnetic field of a generator.

A tax credit granted for specific types of investments.

A fuel gas with a heating value between 90 and 200 Btu per cubic foot.

A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.

The fossil fuels: coal, oil, and natural gas.

A solar heating system that uses a liquid as the heat transfer fluid.

The monochromatic irradiance of a surface per unit bandwidth at a particular wavelength, usually expressed in Watts per square meter-nanometer bandwidth.

A type of anaerobic digester that has a horizontal tank in which a constant volume of material is added and forces material in the tank to move through the tank and be digested.

Restrictions on the use of a property.

The region between an n-layer and a p-layer in a single material, photovoltaic cell.

A generator with a single armature coil, which may have many turns and the alternating current output consists of a succession of cycles.

The percentage of a building's seasonal energy requirements that can be met by a solar energy device(s) or system(s).