The process of modifying a building's structure.

A type of High-Intensity Discharge (HID) lamp that uses sodium under high pressure as the primary light-producing element. These high efficiency lights produce a golden white color and are used for interior industrial applications, such as in warehouses a ...

Materials that prevent or slow down the movement of heat.

The measure of closeness in shape between a waveform and it's fundamental component.

A common utility monetary measure equal to one-thousandth of a dollar or a tenth of a cent.

As defined by the Comprehensive National Energy Act of 1992 (or the Energy Policy Act; EPAct): any organic matter from a plant which is planted for the exclusive purpose of being used to produce energy." This does not include wood or agricultural wastes o ...

An empirical measure of the quantity of light. It is based upon the spectral sensitivity of the photosensors in the human eye under high (daytime) light levels. Photometrically it is the luminous flux emitted with a solid angle (1 steradian) by a point so ...

Methyl Tertiary Butyl Ether (MTBE) is an ether compound used as a gasoline blending component to raise the oxygen content of gasoline. MTBE is made by combining isobutylene (from various refining and chemical processes) and methanol (usually made from nat ...

The amount of fuel necessary to generate one kilowatt-hour of electricity.

A solar energy system that produces electricity with a PV module, and collects thermal energy from the module for heating. There are no commercially available systems available (as of 11/97).

A computer software program that simulates energy consumption of commercial buildings; used for design and auditing purposes.

The nominal voltage for which a conductor or electrical appliance is designed; the reference voltage for identification and not necessarily the precise voltage at which it operates.

The total amount of electricity produced by a power plant.

The water content of a substance (a solid fuel) as measured under specified conditions being the: Dry Basis, which equals the weight of the wet sample minus the weight of a (bone) dry sample divided by the weight of the dry sample times 100 (to get percen ...

A popular term for highly insulating window with a heat loss so low it performs better than an insulated wall in winter, since the sunlight that it admits is greater than its heat loss over a 24 hour period.

The physical material upon which a photovoltaic cell is applied.

A smokestack or flue for exhausting the products of combustion from a combustion appliance.

A unit of mass equal to 1,000 kilograms or 2,204.6 pounds.

The amount of energy an energy storage device or system can store.

The two times of the year when the sun crosses the equator and night and day are of equal length; usually occurs on March 21st (spring equinox) and September 23 (fall equinox).