Pounds/force per square inch absolute.

A unit that equals 20 long hundredweight or 2,240 pounds. Used mainly in England.

A popular term for localized or on-site power generation.

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

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

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

The power required to energize the magnetic field of a generator.

A solar thermal electric central reciever power plant ("power tower") located in Barstow, California, and completed in 1981. The Solar One had a design capacity of 10,000 peak kilowatts, and was composed of a receiver located on the top of a tower surroun ...

A solar energy system designed to provide heat to individual rooms in a building.

A tax credit granted for specific types of investments.

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).

Restrictions on the use of a property.

That portion of an electricity supply system used to deliver electricity from points on the transmission system to consumers.

A method used to estimate building heating loads by assuming that heat loss and gain is proportional to the equivalent heat-loss coefficient for the building envelope.

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

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

A type of solar thermal system where sunlight is concentrated by a curved reflector onto a pipe containing a working fluid that can be used for process heat or to produce electricity. The world's largest solar thermal electric power plants use solar troug ...

The conversion of electric power to visible light by using an electric charge to excite gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produc ...

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

A heat exchanger in which two fluids flow in opposite directions for transfer heat energy from one to the other.