## Fresh w ater U se by U.S. P

ower P lants : Electricity ’

s Thirst for a Precious Resource Glossary and Acronyms

Acre

- foot A volume equal to 325,851 gallons

. Air c ooling See dry cooling

. Basin An area where elevation changes allow rain water and surface water to gather

into streams that flow to a common outlet poin t . S ee also sub

- basin

. Carbon i ntensity The amount of carbon dioxide emitted per unit of electricity generated

. Consumption The amount of water lost to evaporation at a power plant during the cooling

process

. Cooling p ond An onsite reservoir where a power plant stores water for cooling

. Cooling t ower A structure that use s cool s water heated during the thermoelectric steam cooling

process to allow the water to be reused for cooling

. Dry c ooling A cooling system that blows air across stea m

- carrying pipes to cool them, rather

than using water

. East of the Mississippi For purposes of this analysis

, includes Alabama, Connecticut, Delaware, Florida,

Georgia, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Maine, Michigan, Mississippi, North Carolina, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, Vermont, Wisconsin, and West Virginia

. Entrainment The act of pulling larval fish or eggs through a power plant cooling system

. Freshwater In this analysis, all non

- ocean sources of water. Generator A turbine that turns physical energy into electrical energy . A single power plant

may have several generators

. Hybrid c ooling A cooling system that uses dry cooling most of the time, but that can draw on

water for cooling during hot periods

. Hydrologic u nit

c ode (HUC) N umbers used by the U .S. Geological Survey (USGS) to identify all the basins

in the United States (see basin ). A 2

- digit HUC i s used to identify the 21 largest basins

. An 8

- digit HUC is used to iden t if y the smallest sub

- basins (see sub

basin ) , which are within the 2

- digit HUCs. The first two numbers in each 8

- digit HUC indicate the larger 2

- digit HUC basin

. Impingement The trapping of fish against a screen during a power plant’s intake of cooling

water . This injures or kills the fish. Natural gas combined

- cycle A power plant that burns natural gas to generate hot gases , which are used to turn

a turbine to generat e electricity . The plant then uses the hot gas es to make steam to drive an other electricity

- generating turbine

. Once

- through cooling A cooling system that withdraws water from nearby sources and passes it

through pipes to absorb heat from steam

, before releasing the water back to the

source

. Organic fuels Coal, oil, natural ga s, and biomass, as specified in the definition of organic fuels

on EIA forms 860 and 923

. Recirculating cooling A cooling system that withdraws water and uses it several times for cooling

steam before releasing the water back to the source or evaporating it completely

. Renewable energy In t his analysis, includes biomass, geothermal, hydroelectric, solar, and wind

.

Southeast I n t his analysis, states that are part of the South Atlantic Basin: Alabama

,Fresh w ater U se by U.S. P

ower P lants : Electricity ’ s Thirst for a Precious Resource Glossary and Acronyms

Florida, Georgia, Louisiana , Mississippi, North Carolina, South Carolina, Tennessee, and Virginia

. Southwest In t his analysis, states that are part of t he Upper or Lower Colorado Basin:

Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming

. Sub

- basin P art of a basin

, where rain and surface water into streams, often flowing to a

common outlet point where the y join a larger flow. Thermoelectric Power plants that boil water to create steam, which d rives turbines to produce

electricity . This process is also called steam generation. T hermoelectric power plants include all coal, nuclear, oil, biomass, geothermal, and steam

- producing concentrating solar plants , and most natural gas plants. W ind turbines, solar photovoltaic generators, non

- steam concentrating solar power technologies, and natural gas combustion turbines are not thermoelectric plants

. Water i ntensity The amount of water power plants us e

— that i s, withdraw and consume

— per unit of electricity generated

. West of the Mississippi In t his anal ysis, includes Alaska, Arizona, Arkansas, California, Colorado,

Hawaii, Idaho, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, New Mexico, Nevada, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming

. Withdrawal The total amount of water a power plant takes in from a source such as a river,

lake, or aquifer, some of which it returns

.



### Acronyms and Abbreviations

CO2 Carbon dioxide EIA Energy Information Administration EW3 Energy and Water in a Warming World initiative HUC Hydrologic u nit c ode (see Glossary) kWh Kilowatt

- hour MGD Million gallons per day MWh Megawatt

- hour NREL National Renewable Energy Laboratory UCS Union of Concerned Scientist USGS U

. S

. Geological Surve y WaSSI Water Supply Stress Index (see Appendix A)