The type of alternative current generated by alternating current generators, rotary inverters, and solid-state inverters.

A solar photovoltaic device with a specified area.

An energy band in a semiconductor in which electrons can move freely in a solid, producing a net transport of charge.

The amount of energy produced as a percentage of the amount of energy consumed.

A type of combustion heating system in which combustion air is drawn directly from outside and the products of combustion are vented directly outside. These features are beneficial in tight, energy-efficient homes because they will not depressurize a home ...

One pound of water in vapor phase; is NOT steam pressure, which is expressed as pounds per square inch (psi).

The weight of water vapor, per unit weight of dry air.

The value or purchasing power of a dollar in a specified year carried forward or backward.

A tax credit granted for specific types of investments.

The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm).

Any fuel that is in solid form, such as wood, peat, lignite, coal, and manufactured fuels such as pulverized coal, coke, charcoal, briquettes, pellets, etc.

A popular term for localized or on-site power generation.

The lower or net heat of combustion for a fuel that assumes that all products of combustion are in a gaseous state. (See Net Heating Value below.)

An automatic valve that is opened or closed by an electromagnet.

The amount of power density in sunlight received at the earth's surface at noon on a clear day (about 1,000 Watts/square meter).

A unit of pressure [hydraulic (liquid) or pneumatic (gas)] that does not include atmospheric pressure.

A type of high intensity discharge light that has the most lumens per watt of any light source.

The amount of heat required to raise a unit mass of a substance through one degree, expressed as a ratio of the amount of heat required to raise an equal mass of water through the same range.

A type of furnace in which fuel is burned and the heat is used to produce steam.

The difference between the brightness of an object compared to that of its immediate background.