A raw material that can be converted to one or more products.

A unit of measurement for the ability of a material to retard the diffusion of water vapor at 73.4 F (23 C). A perm, short for permeance, is the number of grains of water vapor that pass through a square foot of material per hour at a differential vapor p ...

A layer of semiconductor material, such as copper indium diselenide or gallium arsenide, a few microns or less in thickness, used to make solar photovoltaic cells.

In a wind energy conversion system, to pitch the turbine blades so as to reduce their lift capacity as a method of shutting down the turbine during high wind speeds.

Fuel gas with a heating value of between 200 and 300 Btu per cubic foot.

The amount of work accomplished by electrical power, usually measured in kilowatt-hours (kWh). One kWh is 1,000 Watts and is equal to 3,413 Btu.2.The energy of moving electrons.

A turbine that is driven by high velocity jets of water or steam from a nozzle directed to vanes or buckets attached to a wheel. (A pelton wheel is an impulse hydroturbine).

A battery-powered electrically driven vehicle.

The wind speed with 50 percent probability of occurring.

The decomposition of organic material to alcohol, methane, etc., by organisms, such as yeast or bacteria, usually in the absence of oxygen.

A device that tracks the movement of the sun; used to orient solar concentrating systems.

A construction element that inhibits termites from entering building foundations and walls.

The quantity of heat necessary to raise the temperature of a specific mass of a substance by one degree.

The arrangement, proportion, and design of windows in a building.

A registered trademark name for houses built with tires, aluminum cans, and earth.

A device for converting continuous circular motion into reciprocating rectilinear motion.

The sum of all the costs both recurring and nonrecurring, related to a product, structure, system, or service during its life span or specified time period.

The discomfort or interference with visual perception when viewing a bright object against a dark background.

A house built into the ground or slope of a hill, or which has most or all exterior surfaces covered with earth.

A unit or measure of electricity supply or consumption of 1,000 Watts over the period of one hour; equivalent to 3,412 Btu.