A device in which organic material is biochemically decomposed (digested) by anaerobic bacteria to treat the material and/or to produce biogas.

A curve on a chart showing power (kW) supplied (on the horizontal axis) plotted against time of occurrence (on the vertical axis) to illustrate the variance in a load in a specified time period.

The amount of energy produced as a percentage of the amount of energy consumed.

A unit of illuminance; equal to one lumen per square foot.

The net south-facing glazing area projected on a vertical plane. Also, the solid area covered at any instant by a wind turbine's blades from the perspective of the direction of the windstream (as opposed to the swept area).

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

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.

The tendency of the sunlight to electricity conversion efficiency of amorphous silicon photovoltaic devices to degrade (drop) upon initial exposure to light.

A solar photovoltaic device with a specified area.

Salt mixtures with potential applications as solar thermal energy storage materials.

The amount of solar energy that passes through a glazing material, expressed as a percentage.

The process by which sunlight directly enters a building through the windows and is absorbed and stored in massive floors or walls.

The two times of the year when the sun is apparently farthest north and south of the earth's equator; usually occurring on or around June 21 (summer solstice in northern hemisphere, winter solstice for southern hemisphere) and December 21 (winter solstice ...

A heating unit where heat is distributed by means of convection or fans.

A measure of the quality of a light source by expressing the color appearance correlated with a black body.

Pounds of pressure per square inch.

The process of storing, or converting energy from one form to another, for later use; storage devices and systems include batteries, conventional and pumped storage hydroelectric, flywheels, compressed gas, and thermal mass.

The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.

The transfer of heat by means of air currents.

The process of controlling indoor moisture levels and condensation.