Two metals of different coefficients of expansion welded together so that the piece will bend in one direction when heated, and in the other when cooled, and can be used to open or close electrical circuits, as in thermostats.

The difference between net electrical system capability and system maximum load requirements (peak load); the margin of capability available to provide for scheduled maintenance, emergency outages, system operating requirements and unforeseen loads.

In heating and cooling system distribution ductwork, the transformation pieces connecting horizontal round leaders to vertical rectangular stacks.

A method of growing large size, high quality semiconductor crystal by slowly lifting a seed crystal from a molten bath of the material under careful cooling conditions.

A quantity of (solid) biomass fuel equal to 2,400 pounds bone dry.

A type of air compressor in which air is compressed in a series of stages as it flows axaily through a decreasing tubular area.

A method of predicting heating and/or cooling loads using instantaneous load calculation at different outdoor dry-bulb temperatures, and multiplying the result by the number of hours of occurrence of each temperature.

A region of transition between semiconductor layers, such as a p/n junction, which goes from a region that has a high concentration of acceptors (p-type) to one that has a high concentration of donors (n-type).

A combustible gas created by anaerobic decomposition of organic material, composed primarily of methane, carbon dioxide, and hydrogen sulfide.

The power conduit of an electric power plant; the starting point of the electric transmission system.

Primitive plants, usually aquatic, capable of synthesizing their own food by photosynthesis.

In a solar energy system, refers to all components other than the collector. In terms of costs, it includes design costs, land, site preparation, system installation, support structures, power conditioning, operation and maintenance costs, indirect storag ...

An electrical conductor that serves as a common connection for two or more electrical circuits; may be in the form of rigid bars or stranded conductors or cables.

The air external to a building or device.

A process for carrying out a reaction in which the reactants are fed in discrete and successive charges.

A type of heating fuel derived by refining crude oil that has a boiling range at atmospheric pressure from 400 degrees to 550 degrees F.

42 U.S. gallons (306 pounds of oil, or 5.78 million Btu).

The illuminating power of a standard candle employed as a unit for determining the illuminating quality of an illuminant.

The use of direct, diffuse, or reflected sunlight to provide supplemental lighting for building interiors.

The amount of electromotive force, measured in volts, that exists between two points.