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

A measure of the electrical resistance of a material equal to the resistance of a circuit in which the potential difference of 1 volt produces a current of 1 ampere.

The ratio of a photovoltaic cell's actual power to its power if both current and voltage were at their maxima. A key characteristic in evaluating cell performance.

Air brought into a building from outside to replace exhaust air.

A battery-powered electrically driven vehicle.

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

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.

A refined petroleum product suitable for use as a fuel in internal combustion engines.

A class of power generator that is not a regulated utility and that has generating plants for the purpose of supplying electric power required in the conduct of their industrial and commercial operations.

A mechanical/electrical device used to pull air out of an interior space; usually located in the highest location of a building, in the ceiling, and venting to the attic or directly to the outside.

A device consisting of two dissimilar conductors with their ends connected together. When the two junctions are at different temperatures, a small voltage is generated.

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

The wind speed with 50 percent probability of occurring.

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.

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

A heating system, such as a solar water heater or geothermal heatpump, in which the working fluid is heated and used directly; in an open-loop solar system, the domestic water is circulated in the collector loop.

The path followed by electrons from a generation source, through an electrical system, and returning to the source.

The transfer of heat through a material by the transfer of kinetic energy from particle to particle; the flow of heat between two materials of different temperatures that are in direct physical contact.

A unit used to rate the performance of a solar photovoltaic (PV) cells, modules, or arrays; the maximum nominal output of a PV device, in Watts (Wp) under standardized test conditions, usually 1000 Watts per square meter of sunlight with other conditions, ...