The measure of overall efficiency for a variety of appliances. For water heaters, the energy factor is based on three factors: 1) the recovery efficiency, or how efficiently the heat from the energy source is transferred to the water; 2) standby losses, o ...

The process of forcing, either manually or automatically, a wind turbine's blades out of the direction of the wind in order to stop the blades from turning.

The interior space of a building that is heated or cooled.

A type of hydropower turbine that contains a runner that has water passages through it formed by curved vanes or blades. As the water passes through the runner and over the curved surfaces, it causes rotation of the runner. The rotational motion is transm ...

The process of sending or moving electricity from one point to another; usually defines that part of an electric utility's electric power lines from the power plant buss to the last transformer before the customer's connection.

The process of changing regulatory policies and laws to increase competition among suppliers of commodities and service. The process of deregulating the electric power industry was initiated by the Energy Policy Act of 1992. (See also Restructuring)

The duration and periodicity of the operation of a device.

The actual power rating that is developed by a motor before losses occur.

A type of solar thermal collector where the heat transfer fluid flows through tubes formed in the absorber plate.

A measure of the relative flame spread, and smoke development, from a material being tested. The flame spread rating is a single number comparing the flame spread of a material with red oak, arbitrarily given the number 100 and asbestos cement board with ...

An optical device for concentrating light that is made of concentric rings that are faced at different angles so that light falling on any ring is focused to the same point.

The production of energy by a system or appliance at a level less than its design or nominal capacity.

The ratio of solar radiation captured and transfered to the collector (heat transfer) fluid.

The liquid resulting when water vapor contacts a cool surface; also the liquid resulting when a vaporized working fluid (such as a refrigerant) is cooled or depressurized.

To condition/cool air by dessication.

The torque at the bottom of a speed (rpm) versus torque curve. The torque developed by the motor is a percentage of the full-load or rated torque. At this torque the speed, the rotational speed of the motor as a percentage of synchronous speed is zero. Th ...

A form of solar concentrating collector that does not track the sun.

The duct(s) of a forced air heating/cooling system through which heated or cooled air is supplied to rooms by the action of the fan of the central heating or cooling unit.

The force per unit area acting on the surface of a solid boundary parallel to the flow.

In reference to a wind turbine, a condition when the rotor stops turning.