The demand on an energy producing system; the energy consumption or requirement of a piece or group of equipment.

A measure of the efficacy (efficiency) of lamps. It indicates the amount of light (lumens) emitted by the lamp for each unit of electrical power (Watts) used.

An electric generator consists of an armature and a field structure. The armature carries the wire loop, coil, or other windings in which the voltage is induced, whereas the field structure produces the magnetic field. In small generators, the armature is ...

The sum of sensible heat and latent heat in a substance above a base temperature, typically 32 degrees Fahrenheit.

The process of burning; the oxidation of a material by applying heat, which unites oxygen with a material or fuel.

In reference to solar photovoltaic cell manufacure, a method of growing a large-size, high-quality crystal whereby coils heat a polycrystalline ingot placed atop a single-crystal seed. As the coils are slowly raised the molten interface beneath the coils ...

A building that is elongated in the east-west direction, with the majority of the windows on the south side. The area of the windows is generally limited to about 7% of the total floor area. A sun-tempered design has no added thermal mass beyond what is a ...

An amount to be paid for energy periodically by a customer without regard to demand or energy consumption.

A column of gas at standard conditions of temperature and pressure (32 degrees Fahrenheit and one atmosphere).

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

A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements. These lights have the best Color Rendition Index (CRI) of the High-Intensity Discharge lamps. They can be used for commercial interior lightin ...

The process of changing the structure of the electric power industry from one of guaranteed monopoly over service territories, as established by the Public Utility Holding Company Act of 1935, to one of open competition between power suppliers for custome ...

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

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

The fluid, liquid (water or water/antifreeze solution) or air, used to absorb solar energy and transfer it for direct use, indirect heating of interior air or domestic water, and/or to a heat storage medium.

A plastic foam insulation product, pressed or extruded into board-like forms, used as sheathing and insulation for interior basement or crawl space walls or beneath a basement slab; can also be used for exterior applications inside or outside foundations, ...

A type of house that has massive amounts of insulation, airtight construction, and controlled ventilation without sacrificing comfort, health, or aesthetics.

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

Sunlight scattered by atmospheric particles and gases so that it arrives at the earth's surface from all directions and can not be focused.

The process of removing moisture; involves evaporation.