A particle of light that acts as an individual unit of energy.

A cooling device that uses mechanical energy to produce chilled water.

The lowest wind speed at which a wind turbine begins producing useable power.

An electrical device that resists electric current flow.

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

The temperature of the air as measured by a standard thermometer.

The number of cycles through which an alternating current passes per second; in the U.S. the standard for electricity generation is 60 cycles per second (60 Hertz).

The direct, diffuse, and reflected solar radiation that strikes a surface.

A type of combustion heating system in which combustion air is drawn directly from outside and the products of combustion are vented directly outside. These features are beneficial in tight, energy-efficient homes because they will not depressurize a home ...

A complete lighting unit consisting of a lamp(s), housing, and connection to the power circuit.

A high-efficiency photovoltaic device containing two or more cell junctions, each of which is optimized for a particular part of the solar spectrum.

A term for the process of transmitting electricity over transmission lines not owned by the supplier of the electricity to a retail customer of the supplier. With retail wheeling, an electricity consumer can secure their own supply of electricity from a b ...

A slightly sloped roof, usually with a tar and gravel cover. Most commercial buildings use this kind of roof.

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

A power plant that uses two thermodynamic cycles to achieve higher overall system efficiency; e.g.: the heat from a gas-fired combustion turbine is used to generate steam for heating or to operate a steam turbine to generate additional electricity.

A method of depositing thin semiconductor photovoltaic) films. With this method, physical processes, such as thermal evaporation or bombardment of ions, are used to deposit elemental semiconductor material on a substrate.

A self-contained toilet that use the process of aerobic decomposition (composting) to break down feces into humus and odorless gases.

An energy band in a semiconductor in which electrons can move freely in a solid, producing a net transport of charge.

The highest wind speed at which a wind turbine stops producing power.

Water heated for residential washing, bathing, etc.