A heating unit where heat is distributed by means of convection or fans.

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.

A commmon term refering to an electricity transmission and distribution system.

Amorphous silicon with a small amount of incorporated hydrogen. The hydrogen neutralizes dangling bonds in the amorphous silicon, allowing charge carriers to flow more freely.

Turning off or disconnecting loads to limit peak demand.

The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm).

The angle that a solar collector is positioned from horizontal.

A power plant that generates power by combusting a fuel.

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.

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 method of controlling a wind turbine's speed by varying the orientation, or pitch, of the blades, and thereby altering its aerodynamics and efficiency.

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

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.

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

The resistance between metallic contacts and the semiconductor.

A high R-value insulation product usually made from urethane that can be injected into wall cavities, or sprayed onto roofs or floors, where it expands and sets quickly.

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

The minimum temperature at which sufficient vapor is released by a liquid or solid (fuel) to form a flammable vapor-air mixture at atmospheric pressure.

A type of solar photovoltaic device made in a continuous process of pulling material from a molten bath of photovoltaic material, such as silicon, to form a thin sheet of material.

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.