The ratio of a photovoltaic cell's actual power to its power if both current and voltage were at their maxima. A key characteristic in evaluating cell performance.

A unit of power equal to 1 billion Watts; 1 million kilowatts, or 1,000 Megawatts.

A thin sheet of material (metal) of a heat exchanger that conducts heat to a fluid.

A material used to seal gaps around windows and exterior doors.

The maximum load that a device is capable of carrying.

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

A battery-powered electrically driven vehicle.

A measure of air purity that is equal to one complete air change (in an interior space).

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

A federal agency established in 1933 to develop the Tennessee river valley region of the southeastern U.S., and which is now nation's largest power producer.

A material that can be used to store thermal energy as latent heat. Various types of materials have been and are being investigated such as inorganic salts, eutectic compounds, and parrafins, for a variety of applications, including solar energy storage ( ...

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

The decomposition of organic material to alcohol, methane, etc., by organisms, such as yeast or bacteria, usually in the absence of oxygen.

The storage of heat energy during utility off-peak times at night, for use during the next day without incurring daytime peak electric rates.

The point or outdoor temperature where the heating capacity of a heat pump matches the heating requirements of a building.

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 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 profile of how the wind speed changes with height above the surface of the ground or water.

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 diagram that indicates the average percentage of time that the wind blows from different directions, on a monthly or annual basis.