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

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 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.

An amount paid by a customer for being connected to an electricity supplier's transmission and distribution system.

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

A renewable energy system that includes two different types of renewable energy technologies that produce the same type of energy; for e.g., a wind turbine and a solar photovoltaic array combined to meet a power demand.

Pounds/force per square inch absolute.

A widely used rate of return for performing economic analysis. This method solves for the interest rate that equates the equivalent worth of an alternative's cash receipts or savings to the equivalent worth of cash expenditures, including investments. The ...

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

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

Restrictions on the use of a property.

see Peak Watt.

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

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

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).

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

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

A tax credit granted for specific types of investments.

Materials with high thermal energy storage capacity contained in or part of a building's walls, floors, or freestanding elements.