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

The fossil fuels: coal, oil, and natural gas.

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

That portion of an electricity supply system used to deliver electricity from points on the transmission system to consumers.

The air that is supplied to the combustion chamber of a furnace.

The percentage of a building's seasonal energy requirements that can be met by a solar energy device(s) or system(s).

see Solar Spectrum above.

A coating applied to the surface of the glazing of a window to reduce heat transfer through the window.

The damping of interior temperature fluctuations by massive construction.

A method of financial and economic analysis used to determine present and future values of investments or expenses.

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.

The mean distance a free electron or hole moves before recombining with another hole or electron.

A plot of a wind energy conversion device's power output versus wind speed.

A commonly used analysis for reporting fuel properties; may be on a dry (moisture free) basis, as "fired", or on an ash and moisture free basis. Fractions usually reported include: volatile matter, fixed carbon, moisture, ash, and heating value (higher he ...

A chemical element, of atomic number 14, that is semi-metallic, and an excellent semiconductor material used in solar photovoltaic devices; commonly found in sand.

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

A water and energy conserving device that limits the amount of water that a faucet or showerhead can deliver.

The interior area of a building, calculated in square feet or meters.

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

The region between an n-layer and a p-layer in a single material, photovoltaic cell.