A form of movable insulation that uses tiny polystyrene beads blown into the space between two window panes.

Solar radiation that is not scattered by dust or water droplets.

A wall that carries ceiling rafters or roof trusses.

Two metals of different coefficients of expansion welded together so that the piece will bend in one direction when heated, and in the other when cooled, and can be used to open or close electrical circuits, as in thermostats.

A method of predicting heating and/or cooling loads using instantaneous load calculation at different outdoor dry-bulb temperatures, and multiplying the result by the number of hours of occurrence of each temperature.

Combination of two power plant turbine cycles utilizing two different working fluids for power production. The waste heat from the first turbine cycle provides the heat energy for the operation of the second turbine, thus providing higher overall system e ...

Binary cycle systems can be used with liquids at temperatures less than 350 F (177 C). In these systems, the hot geothermal liquid vaporizes a secondary working fluid, which then drives a turbine.

The weight of oxygen taken up mainly as a result of the oxidation of the constituents of a sample of water by biological action; expressed as the number of parts per million of oxygen taken up by the sample from water originally saturated with air, usuall ...

The conversion of one form of energy into another by the action of plants or microorganisms. The conversion of biomass to ethanol, methanol, or methane.

The conversion of the complex carbohydrates in organic material into energy.

A combustible gas created by anaerobic decomposition of organic material, composed primarily of methane, carbon dioxide, and hydrogen sulfide.

The process of decomposing biomass with anaerobic bacteria to produce biogas.

As defined by the Energy Security Act (PL 96-294) of 1980, "any organic matter which is available on a renewable basis, including agricultural crops and agricultural wastes and residues, wood and wood wastes and residues, animal wastes, municipal wastes, ...

Energy produced by the conversion of biomass directly to heat or to a liquid or gas that can be converted to energy.

Biomass converted directly to energy or converted to liquid or gaseous fuels such as ethanol, methanol, methane, and hydrogen.

The conversion of biomass into a gas, by biogasification (see above) or thermal gasification, in which hydrogen is produced from high-temperature gasifying and low-temperature pyrolysis of biomass.

The action of light on a biological system that results in the dissociation of a substrate, usually water, to produce hydrogen.

An ideal substance that absorbs all radiation falling on it, and reflecting nothing.

The device in an air conditioner that distributes the filtered air from the return duct over the cooling coil/heat exchanger. This circulated air is cooled/heated and then sent through the supply duct, past dampers, and through supply diffusers to the liv ...

A device used by energy auditors to pressurize a building to locate places of air leakage and energy loss.