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

A type of solar thermal system where air is heated in a collector and either transferred directly to the interior space or to a storage medium, such as a rock bin.

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.

An electrical conductor/cable that carries electricity from a generator to other locations for distribution.

Electromagnetic energy transmitted from the sun (solar radiation). The amount that reaches the earth is equal to one billionth of total solar energy generated, or the equivalent of about 420 trillion kilowatt-hours.

The generation of electric power by a heat engine which converts part of the heat generated by combustion of the fuel into mechanical motion to operate an electric generator.

In reference to a wind energy conversion device, the ratio of rotor blade surface area to the frontal, swept area that the rotor passes through.

A registered trademark for plastic sheeting material that can be used as a vapor retarder. This plastic is used to make grocery bags. It is a long chain of carbon atoms with 2 hydrogen atoms attached to each carbon atom.

Solar radiation that arrives in a straight line from the sun.

A construction element applied to the outermost surface of an exterior wall.

The heat produced by sources of heat in a building (occupants, appliances, lighting, etc).

The current flowing freely through an external circuit that has no load or resistance; the maximum current possible.

A type of furnace or reactor in which fuel particles are combusted while suspended in a stream of hot gas.

A device for transforming the quality and quantity of electrical energy; also an inverter.

The amount of energy that a building absorbs due to solar energy striking its exterior and conducting to the interior or passing through windows and being absorbed by materials in the building.

A term used for materials used to absorb and store solar energy.

The legal issues related to protecting or ensuring access to sunlight to operate a solar energy system, or use solar energy for heating and cooling.

The angle between a line from a point on the earth's surface to the center of the solar disc, and a line extending horizontally from the point.

The elements and compounds that result from the combustion of a fuel.

A window glazing coating, usually tinted bronze or gray, used to reduce building cooling loads, glare, and fabric fading.