A unit used to rate the performance of a solar photovoltaic (PV) cells, modules, or arrays; the maximum nominal output of a PV device, in Watts (Wp) under standardized test conditions, usually 1000 Watts per square meter of sunlight with other conditions, ...

A house built into the ground or slope of a hill, or which has most or all exterior surfaces covered with earth.

Ventilation that is created by the differences in the distribution of air pressures around a building. Air moves from areas of high pressure to areas of low pressure with gravity and wind pressure affecting the airflow. The placement and control of doors ...

The use of devices to limit or prevent the release of pollution into the atmosphere.

A system capable of rotating about one axis.

A device used to control temperatures; used to control the operation of heating and cooling devices by turning the device on or off when a specified temperature is reached.

Any coefficient used to calculate heat transmission by conduction, convection, or radiation through materials or structures.

A measure of the amount of light incident on a surface; measured in foot-candles or Lux.

The quantity of heat necessary to raise the temperature of a specific mass of a substance by one degree.

The amount of energy derived from an electrical source per unit quantity of electricity passing through the source.2. Electrical potential; voltage.

A class of power generator that is not a regulated utility and that has generating plants for the purpose of supplying electric power required in the conduct of their industrial and commercial operations.

A construction element used for ceiling support.

The practice of using a single meter to measure consumption and generation of electricity by a small generation facility (such as a house with a wind or solar photovoltaic system). The net energy produced or consumed is purchased from or sold to the gener ...

The distance between similar points on successive waves.

An idealized process in which a working fluid (water, air, ammonia, etc) successively changes its state (from a liquid to a gas and back to a liquid) for the purpose of producing useful work or energy, or transferring energy.

The space within a building or structure that is normally occupied by people, and that may be conditioned (heated, cooled and/or ventilated).

The coldest months of the year; months where average daily temperatures fall below 65 degrees Fahrenheit creating demand for indoor space heating.

A heating system, such as a solar water heater or geothermal heatpump, in which the working fluid is heated and used directly; in an open-loop solar system, the domestic water is circulated in the collector loop.

The period of low energy demand, as opposed to maximum, or peak, demand.

The path followed by electrons from a generation source, through an electrical system, and returning to the source.