The wind speed with 50 percent probability of occurring.

The distance between similar points on successive waves.

A construction element used for ceiling support.

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

A system capable of rotating about one axis.

A measure of the efficiency of an appliance's energy efficiency.

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 ...

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 turbine that is driven by high velocity jets of water or steam from a nozzle directed to vanes or buckets attached to a wheel. (A pelton wheel is an impulse hydroturbine).

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

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.

A type of motor that has a rotor with electrical windings connected through slip rings to the external power circuit. An external resistance controller in the rotor circuit allows the performance of the motor to be tailored to the needs of the system and ...

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

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

A water heater that heats water before it is directly distributed for end use as required; a demand water heater.

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.

A device consisting of two dissimilar conductors with their ends connected together. When the two junctions are at different temperatures, a small voltage is generated.

The transfer of heat through a material by the transfer of kinetic energy from particle to particle; the flow of heat between two materials of different temperatures that are in direct physical contact.

A way of joining photovoltaic cells by connecting positive leads to negative leads; such a configuration increases the voltage.

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 ...