A term used to describe a technologically advanced window system that contains glazing that can change or switch its optical qualities when a low voltage electrical signal is applied to it, or in response to changes in heat or light.

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 power plant that uses two thermodynamic cycles to achieve higher overall system efficiency; e.g.: the heat from a gas-fired combustion turbine is used to generate steam for heating or to operate a steam turbine to generate additional electricity.

The transfer of heat by means of air currents.

Fabricated as a single structure.

Ethanol.

Air that provides the necessary oxygen for complete, clean combustion and maximum heating value.

Turning off or disconnecting loads to limit peak demand.

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

The device in an air conditioner or heat pump in which the refrigerant condenses from a gas to a liquid when it is depressurized or cooled.

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.

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

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

A unit of pressure [hydraulic (liquid) or pneumatic (gas)] that does not include atmospheric pressure.

Legal documents that regulate construction to protect the health, safety, and welfare of people. Codes establish minimum standards but do not guarantee efficiency or quality.

Legislation authorizing a U.S. biomass and alcohol fuel program, and that authorized loan guarantees and price guarantees and purchase agreements for alcohol fuel production.

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 stationary or rotating vent used to ventilate attics or cathedral ceilings; usually made of galvanized steel, or polypropylene.

A passage for surplus water to flow over or around a dam.

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