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

Solid fuels made from primarily wood sawdust that is compacted under high pressure to form small (about the size of rabbit feed) pellets for use in a pellet stove.

The amount of work accomplished by electrical power, usually measured in kilowatt-hours (kWh). One kWh is 1,000 Watts and is equal to 3,413 Btu.2.The energy of moving electrons.

The unit price and quantity to which it applies as specified in a rate schedule or contract.

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

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 ( ...

A construction element that inhibits termites from entering building foundations and walls.

A type of turbine in which combusted, pressurized gas is directed against a series of blades connected to a shaft, which forces the shaft to turn to produce mechanical energy.

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

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 measure of the electrical resistance of a material equal to the resistance of a circuit in which the potential difference of 1 volt produces a current of 1 ampere.

A device for converting mechanical energy to electrical energy.

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 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.

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

A refined petroleum product suitable for use as a fuel in internal combustion engines.

A group of wind turbines interconnected to a common utility system through a system of transformers, distribution lines, and (usually) one substation. Operation, control, and maintenance functions are often centralized through a network of computerized mo ...

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

A device that tracks the movement of the sun; used to orient solar concentrating systems.

The sum of all the costs both recurring and nonrecurring, related to a product, structure, system, or service during its life span or specified time period.