WARRANTY - In the context of vehicles, it refers to an engine manufacturer's guarantee that the engine will meet "certified" engine standards at 50,000 miles or the engine will be replaced. Retrofits may generally void an engine warranty.
WATER HEATER - An appliance for supplying hot water for purposes other than space heating or pool heating. [See California Code of Regulations, Title 20, Section 1602(f)(8)]
WATSCO - The Western Association for Transmission System Coordination.
WATT - A unit of measure of electric power at a point in time, as capacity or demand.
WATT-HOUR - One watt of power expended for one hour.
WEATHERSTRIPPING - Specially designed strips, seals and gaskets installed around doors and windows to limit air leakage.
WET-BULB TEMPERATURE - The temperature at which water, by evaporating into air, can bring the air to saturation at the same temperature. Wet-bulb temperature is measured by a wet-bulb psychrometer.
WHEELING - The transmission of electricity by an entity that does not own or directly use the power it is transmitting. Wholesale wheeling is used to indicate bulk transactions in the wholesale market, whereas retail wheeling allows power producers direct access to retail customers. This term is often used colloquially as meaning transmission.
WHOLE HOUSE FAN - A system capable of cooling a house by exhausting a large volume of warm air when the outside air is cool.
WATT - A unit of measure of electric power at a point in time, as capacity or demand. One watt of power maintained over time is equal to one joule per second. Some Christmas tree lights use one watt. The Watt is named after Scottish inventor James Watt and is capitalized when shortened to w and used with other abbreviations, as in kWh.
WATT-HOUR - One watt of power expended for one hour. One thousandth of a kilowatt-hour.
WHEELING - Using a utility's lines to transport power from one neighboring system to another.
WHOLESALE COMPETITION - A system whereby a distributor of power would have the option to buy its power from a variety of power producers, and the power producers would be able to compete to sell their power to a variety of distribution companies.
WHOLESALE POWER MARKET - The purchase and sale of electricity from generators to resellers (who sell to retail customers) along with the ancillary services needed to maintain reliability and power quality at the transmission level.
WHOLESALE TRANSMISSION SERVICES - The transmission of electric energy sold, or to be sold, at wholesale in interstate commerce (from EPAct).
WIRES CHARGE - A broad term which refers to charges levied on power suppliers or their customers for the use of the transmission or distribution wires.
WRTA - Short for the Western Regional Transmission Association.
WSCC - Acronym for the Western System Coordinating Council - a voluntary industry association created to enhance reliability among western utilities.
WSPP - Acronym for the Western Systems Power Pool- a FERC approved industry institution that provides a forum for short-term trades in electric energy, capacity, exchanges and transmission services. The pool consists of approximately 50 members and serves 22 states, a Canadian province and 60 million people. The WSSP is headquartered in Phoenix, Arizona.