A type of building ventilation system that uses fans or blowers to provide fresh air to rooms when the forces of air pressure and gravity are not enough to circulate air through a building.

The ratio of actual power being used in a circuit, expressed in watts or kilowatts, to the power that is apparently being drawn from a power source, expressed in volt-amperes or kilovolt-amperes.

An amount paid by a customer for being connected to an electricity supplier's transmission and distribution system.

A device in which organic material is biochemically decomposed (digested) by anaerobic bacteria to treat the material and/or to produce biogas.

The process of storing, or converting energy from one form to another, for later use; storage devices and systems include batteries, conventional and pumped storage hydroelectric, flywheels, compressed gas, and thermal mass.

A term used to describe solar thermal, central receiver, power systems, where an array of reflectors focus sunlight onto a central receiver and absorber mounted on a tower.

A unit of volume equal to 1 cubic foot at a pressure base of 14.73 pounds standard per square inch absolute and a temperature base of 60 degrees Fahrenheit.

A method used to estimate building heating loads by assuming that heat loss and gain is proportional to the equivalent heat-loss coefficient for the building envelope.

A machine supplied with external energy that is converted into force and/or motion.

Electromagnetic radiation whose wavelengths lie in the range from 0.75 micrometer to 1000 micrometers; invisible long wavelength radiation (heat) capable of producing a thermal or photovoltaic effect, though less effective than visible light.

The solar power density incident on a surface of stated area and orientation, usually expressed as Watts per square meter or Btu per square foot per hour.

An axail flow fan mounted in a section of duct to move conditioned air.

Materials with high thermal energy storage capacity contained in or part of a building's walls, floors, or freestanding elements.

A pre-cut layer of insulation applied around a water heater storage tank to reduce standby heat loss from the tank.

In reference to a wind energy conversion system, the wind speed profile in which wind speeds increase with the logarithmic of the height of the wind turbine above the ground.

A unit that equals 20 long hundredweight or 2,240 pounds. Used mainly in England.

Pounds of pressure per square inch.

A unit of illuminance; equal to one lumen per square foot.

A plan developed by an electric utility, sometimes as required by a public regulatory commission or agency, that defines the short and long term capacity additions (supply side) and demand side management programs that it will undertake to meet projected ...

The apparent angle of the sun north or south of the eath's equatorial plane. The earth's rotation on its axis causes a daily change in the declination.