A solar heating system that uses a liquid as the heat transfer fluid.

The conversion of electric power to visible light by using an electric charge to excite gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produc ...

The time of the day, at a specific location, when the sun reaches its highest, apparent point in the sky; equal to true or due, geographic south.

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

The ratio of the sum of the noncoincidental maximum demands of two or more loads to their coincidental maximum demands for the same period.

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.)

see Peak Watt.

Pounds/force per square inch absolute.

The amount of solar energy that passes through a glazing material, expressed as a percentage.

The process by which sunlight directly enters a building through the windows and is absorbed and stored in massive floors or walls.

A measure of the quality of a light source by expressing the color appearance correlated with a black body.

The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.

The total distribution of electromagnetic radiation emanating from the sun. The different regions of the solar spectrum are described by their wavelength range. The visible region extends from about 390 to 780 nanometers (a nanometer is one billionth of o ...

A tax credit granted for specific types of investments.

The fine particulate matter entrained in the flue gases of a combustion power plant.

A deposition process whereby heat is used to break molecules into elemental sources that are then spray deposited on a substrate.

The potentially useful byproducts of ethanol fermentation process.

Freshly cut, unseasoned, wood.

A renewable energy system that includes two different types of renewable energy technologies that produce the same type of energy; for e.g., a wind turbine and a solar photovoltaic array combined to meet a power demand.

A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.