The angular position of the sun at solar noon with respect to the plane of the equator.

A device that converts heat or sunlight directly to electricity, invented by Standford Ovshinsky, that has a unique glass composition that changes from an electrically non-conducting state to a semiconducting state.

The pressure corresponding to the outlet velocity of a fan; the kinetic energy per unit volume of flowing air.

A device used to simulate the angle of the sun for assessing shading potentials of building structures or landscape features.

A type of insulation material with fine, closed cells, containing a mixture of air and refrigerant gas. This insulation has a high R-value, good moisture resistance, and high structural strength compared to other rigid insulation materials.

A facility or piece of equipment that produces electricity.

The relationship of a building to true south, as specified by the direction of its longest axis.

The pressure of the steam or water in a boiler as measured; usually expressed in pounds per square inch gauge (psig).

The process of moving air (changing) into and out of an interior space either by natural or mechanically induced (forced) means.

The amount of BTU's/hour or kW's produced by a heating system from the burning of a fuel.

A two step process where in the first step natural gas is exposed to a high-temperature steam to produce hydrogen, carbon monoxide, and carbon dioxide. The second step is to convert the carbon monoxide with steam to produce additional hydrogen and carbon ...

The amount of heat energy that may be converted into useful energy from a fuel.

The maximum possible voltage across a photovoltaic cell; the voltage across the cell in sunlight when no current is flowing.

A heat exchanger coil in which a fluid such as water is circulated and a fan blows air over the coil to distribute heat or cool air to the different rooms.

A type of vertical-axis wind machine that has long, thin blades in the shape of loops connected to the top and bottom of the axle; often called an "eggbeater windmill."

The wind speed and direction in an undisturbed flow.

Ratio of useful energy output of a device to the energy input, averaged over an entire heating season.

A term used for a wind energy conversion device that produces electricity; typically having one, two, or three blades.

The housing around a motor that supports the active parts and protects them. They come in different varieties (open, protected) depending on the degree of protection required.

A heat absorbing reaction or a reaction that requires heat.