The vacancy where an electron would normally exist in a solid; behaves like a positively charged particle.

The demand of a consumer of electricity at the time of a power supplier's peak system demand.

Any wholly or partially enclosed space in which combustion takes place.

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

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

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

The local climate of specific place or habitat, as influenced by landscape features.

A component of a heat pump that reverses the refrigerant's direction of flow, allowing the heat pump to switch from cooling to heating or heating to cooling.

The amount of conditioned air to be supplied by a cooling system; usually the maximum amount to be delivered based on a specified number of cooling degree days or design temperature.

An electric current taking a shorter or different path than intended.

A body of water that contains brackish (highly saline) water that forms layers of differing salinity (stratifies) that absorb and trap solar energy. Solar ponds can be used to provide heat for industrial or agricultural processes, building heating and coo ...

The highest possible pressure in a fuel-air mixture before spontaneous ignition occurs.

A chemical element (impurity) added in small amounts to an otherwise pure semiconductor material to modify the electrical properties of the material. An n-dopant introduces more electrons. A p-dopant creates electron vacancies (holes).

A vehicle with an engine capable of operating on two different types of fuels.

A gasifier in which the feedstock (fuel) is suspended by the movement of gas to move it through the gasifier.

The part of an energy utility's charge based on actual energy consumed by the customer; the product of the kilowatt-hour rate and the total kilowatt-hours consumed.

Air that is returned to a heating or cooling appliance from a heated or cooled space.

Solar radiation reflected from the ground onto a solar collector.

A curve that displays load values on the horizontal axis in descending order of magnitude against the percent of time (on the vertical axis) that the load values are exceeded.

Turning off or disconnecting loads to limit peak demand.