The process of using heat that is rejected in one part of a cycle for another function or in another part of the cycle.

One thousand kilowatt-hours or 1 million watt-hours.

A unit of rate of operation. Electrical Hp: a measure of time rate of mechanical energy output; usually applied to electric motors as the maximum output; 1 electrical Hp is equal to 0.746 kilowatts or 2,545 Btu per hour. Shaft Hp: a measure of the actual ...

A measure of the efficiency of converting a fuel to energy and useful work; useful work and energy output divided by higher heating value of input fuel times 100 (for percent).

A pole used to assist in raising a tower.

A hydrocarbon gas obtained from underground sources, often in association with petroleum and coal deposits. It generally contains a high percentage of methane, varying amounts of ethane, and inert gases; used as a heating fuel.

The rate of heat flow required to maintain a specific indoor temperature; usually measured in Btu per hour.

Any device (or plant) that follows the sun's apparent movement across the sky.

A house built using passive solar design techniques.

An elementary particle of an atom with a negative electrical charge and a mass of 1/1837 of a proton; electrons surround the positively charged nucleus of an atom and determine the chemical properties of an atom.

Material such as brick, rock, or stone.

Individual rooms or zones in a building where temperature is controlled separately from other rooms or zones.

The ability to send or wheel electric power to a customer over a transmission and distribution system that is not owned by the generator (seller) of the power.

The electrical power that oscillates between the magnetic field of an inductor and the electrical field of a capacitor. Reactive power is never converted to non-electrical power. Calculated as the square root of the difference between the square of the ki ...

A device that produces mechanical energy directly from two heat reservoirs of different temperatures. A machine that converts thermal energy to mechanical energy, such as a steam engine or turbine.

The total amount of electric energy loss in an electric system between the generation source and points of delivery.

The process of characterizing the wind resource, and its energy potential, for a specific site or geographical area.

The change in direction of a ray of light when it passes through one media to another with differing optical densities.

The products of all combustion processes formed by the combination of nitrogen and oxygen.

A solar water or space-heating system in which solar energy is collected, and/or moved by natural convection without using pumps or fans. Passive systems are typically integral collector/storage (ICS; or batch collectors) or thermosyphon systems. The majo ...