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 ...

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

The average time a minority carrier exists before recombination.

A type of hydroelectric facility that uses the river flow with very little alteration and little or no impoundment of the water.

Materials that prevent or slow down the movement of heat.

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 process of modifying a building's structure.

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

A measure of the probability that a system demand will exceed capacity during a given period; often expressed as the estimated number of days over a long period, frequently 10 years or the life of the system.

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 ...

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

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).

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

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.

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

Technologies that pertain to the generation of electricity.

The physical material upon which a photovoltaic cell is applied.

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).

A device that reduces heat loss at night and during cloudy periods and heat gain during the day in warm weather. A movable insulator could be an insulative shade, shutter panel, or curtain.