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

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

The region between an n-layer and a p-layer in a single material, photovoltaic cell.

A turbine that has a runner with attached blades similar to a propeller used to drive a ship. As water passes over the curved propeller blades, it causes rotation of the shaft.

A generator with a single armature coil, which may have many turns and the alternating current output consists of a succession of cycles.

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

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.

An axail flow fan mounted in a section of duct to move conditioned air.

see Peak Watt.

An empirical measure of the quantity of light. It is based upon the spectral sensitivity of the photosensors in the human eye under high (daytime) light levels. Photometrically it is the luminous flux emitted with a solid angle (1 steradian) by a point so ...

A term used to describe a technologically advanced window system that contains glazing that can change or switch its optical qualities when a low voltage electrical signal is applied to it, or in response to changes in heat or light.

An arrangement of photovoltaic cells or material mounted on a rigid flat surface with the cells exposed freely to incoming sunlight.

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

Methyl Tertiary Butyl Ether (MTBE) is an ether compound used as a gasoline blending component to raise the oxygen content of gasoline. MTBE is made by combining isobutylene (from various refining and chemical processes) and methanol (usually made from nat ...

A single photovoltaic device.

A chemical element that can be used as a fuel since it has a very high energy content.

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.

The angle that a solar collector is positioned from horizontal.

A heat source, such as a space heater, used to provide more heat than that provided by a primary heating source.

The flow rate in these systems is 1/8 to 1/5 the rate of most solar water heating systems. The low-flow systems take advantage of stratification in the storage tank and theoretically allows for the use of smaller diameter piping to and from the collector ...