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

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

The apparent angle of the sun north or south of the eath's equatorial plane. The earth's rotation on its axis causes a daily change in the declination.

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.

A solar photovoltaic device with a specified area.

A source of power (electricity) that can displace power from another source so that source's power can be transmitted to more distant loads.

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 ...

Restrictions on the use of a property.

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.

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

A popular term for energy produced from renewable energy resources.

The value or purchasing power of a dollar in a specified year carried forward or backward.

An axail flow fan mounted in a section of duct to move conditioned air.

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

A deposition process whereby heat is used to break molecules into elemental sources that are then spray deposited on a substrate.

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.

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

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).

The process of controlling indoor moisture levels and condensation.

The transfer of heat by means of air currents.