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

A steady-state fermentation process.

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

A solar thermal electric central reciever power plant ("power tower") located in Barstow, California, and completed in 1981. The Solar One had a design capacity of 10,000 peak kilowatts, and was composed of a receiver located on the top of a tower surroun ...

A type of water heater in which heated water is stored within the tank. Hot water is released from the top of the tank when a hot water faucet is turned. This water is replaced with cold water that flows into the tank and down to just above the bottom pla ...

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

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

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

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.

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

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

One layer of glass in a window frame. It has very little insulating value (R-1) and provides only a thin barrier to the outside and can account for considerable heat loss and gain.

A type of structural, insulated product with foam insulation contained between two facings of drywall, or structural wood composition boards such as plywood, waferboard, and oriented strand board.

A window located on the roof of a structure to provide interior building spaces with natural daylight, warmth, and ventilation.

A panel which covers the underside of an roof overhang, cantilever, or mansard.

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

Energy loads that can be shut off or disconnected at the supplier's discretion or as determined by a contractual agreement between the supplier and the customer.

Energy that is capable or available for doing work; the time rate at which work is performed, measured in horsepower, Watts, or Btu per hour. Electric power is the product of electric current and electromotive force.

A type of automatic thermostat (used on solar heating systems) that responds to temperature differences (between collectors and the storage components) so as to regulate the functioning of appliances (to switch transfer fluid pumps on and off).

A heating system in which steam or hot water for space heating or hot water is piped from a central boiler plant or electric power/heating plant to a cluster of buildings.