Urban Heat Island Effect

Urban Heat Island Effect – Urban heat islands form as vegetation is replaced by asphalt and concrete for roads, buildings, and other structures necessary to accommodate growing populations. These surfaces absorb – rather than reflect – the sun’s heat, causing surface temperatures and overall ambient temperatures to rise. The displacement of trees and shrubs eliminates the natural cooling effects of shading and evapotranspiration (a natural cooling process in which water transpires from a leaf’s surface and evaporates into the atmosphere, reducing ambient temperature), increasing the need for artificial cooling and increasing energy use.

Watt – The rate of energy transfer equivalent to one ampere under an electrical pressure of one volt. One watt equals 1/746 horsepower, or one joule per second. It is the product of Voltage and Current (amperage).

Weatherization – A term commonly applied to improvements made in a building shell to reduce the exchange of indoor and outdoor heat. Common weatherization measures include ceiling, wall and floor insulation, caulking and weather-stripping to reduce air infiltration and exfiltration, storm windows, and solar screens.

Wind Energy – Energy available from the movement of the wind across a landscape caused by the heating of the atmosphere, earth, and oceans by the sun. It is one of the oldest renewable technologies. The most wide spread use of wind power is for pumping water.

Wind Power Plant – A group of wind turbines interconnected to a common utility system through a system of transformers, distribution lines, and (usually) one substation. Operation, control, and maintenance functions are often centralized through a network of computerized monitoring systems, supplemented by visual inspection. This is a term commonly used in the United States. In Europe, it is called a generating station.

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

Wires Company – A regulated utility responsible for providing transmission and distribution services in a deregulated electricity market.