The weight of water vapor, per unit weight of dry air.

A device that converts high-pressure steam, produced in a boiler, into mechanical energy that can then be used to produce electricity by forcing blades in a cylinder to rotate and turn a generator shaft.

A type of insulation that is molded or expanded to produce coarse, closed cells containing air. The rigid cellular structure provides thermal and acoustical insulation, strength with low weight, and coverage with few heat loss paths. Often used to insulat ...

A unit for the quantity of electricity transported in 1 second by a current of 1 ampere.

A law to protect consumers and investors. It placed geographic restrictions on mergers and limitations on diversification into non-utility lines of business and takeovers of electric and gas utilities, and also established regulated monopoly markets or se ...

A group of solar collectors or solar modules connected together.

A solar power station investigated by NASA that entailed a satellite in geosynchronous orbit that would consist of a very large array of solar photovoltaic modules that would convert solar generated electricity to microwaves and beam them to a fixed point ...

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

Water that is suitable for drinking, as defined by local health officials.

A general term applied to the energy that is converted to a form that can not be effectively used (lost) during the operation of an energy producing, conducting, or consuming system.

The requirement that an electric power utility generate or purchase a specified percentage of the power it supplies/sells from renewable energy resources, and thereby guarantee a market for electricity generated from renewable energy resources.

A glazed structure, such as greenhouse or "sunspace."

The angle between a line from a point on the earth's surface to the center of the solar disc, and a line extending horizontally from the point.

The legal issues related to protecting or ensuring access to sunlight to operate a solar energy system, or use solar energy for heating and cooling.

A construction element applied to the outermost surface of an exterior wall.

In reference to a wind energy conversion device, the ratio of rotor blade surface area to the frontal, swept area that the rotor passes through.

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).

Strips of material used to separate multiple panes of glass within the windows.

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.

The use of solar thermal energy or solar electricity to power a cooling appliance. There are five basic types of solar cooling technologies: absorption cooling, which can use solar thermal energy to vaporize the refrigerant; desiccant cooling, which can u ...