Document ID: EPA-HQ-OAR-2009-0865-0039
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-09-23T04:00Z

HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=electricity_in_th
e_united_states" \l "tab1"  Basics  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=electricity_in_th
e_united_states" \l "tab2"  Generation, Sales & Capacity  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=electricity_in_th
e_united_states" \l "tab3"  "Top 10"  

  

Electricity in the United States – Basics

Most of the electricity in the United States is produced using steam
turbines. 

A turbine converts the kinetic energy of a moving fluid (liquid or gas)
to mechanical energy. In a steam turbine, steam is forced against a
series of blades mounted on a shaft, thus rotating the shaft connected
to the generator. The generator, in turn, converts its mechanical energy
to electrical energy based on the relationship between magnetism and
electricity. 

In steam turbines powered by fossil fuels, such as coal, petroleum
(oil), and natural gas, the fuel is burned in a furnace to heat water in
a boiler to produce steam. 

Fossil Fuels Generate Most U.S. Power

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=coal_home"  Coal 
is the most common fuel for generating electricity in the United States.
In 2008, nearly half (48%) of the Country's 4.1 trillion kilowatthours
of electricity used coal as its source of energy.

 

Click to enlarge »

 

  HYPERLINK "http://www.eia.doe.gov/cneaf/electricity/epa/figes1.xls" 
Data for this figure 

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=natural_gas_home"
 Natural gas , in addition to being burned to heat water for steam, can
also be burned to produce hot combustion gases that pass directly
through a turbine, spinning the turbine's blades to generate
electricity. Gas turbines are commonly used when electricity utility
usage is in high demand. In 2008, about 21% of the Nation's electricity
was fueled by natural gas.

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=oil_home" 
Petroleum  can be burned to produce hot combustion gases to turn a
turbine or to make steam to turn a turbine. Residual fuel oil, a product
refined from crude oil, is often the petroleum product used in electric
plants that use petroleum to make steam. Petroleum was used to generate
just over 1% of all electricity in the United States in 2008. 

Nuclear Power Provides About One-Fifth of U.S. Electricity

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=nuclear_home" 
Nuclear power  is a method in which steam is produced by heating water
through a process called nuclear fission. In a nuclear power plant, a
reactor contains a core of nuclear fuel, primarily uranium. When atoms
of uranium fuel are hit by neutrons, they fission (split) releasing heat
and more neutrons. Under controlled conditions, these other neutrons can
strike more uranium atoms, splitting more atoms, and so on. Thereby,
continuous fission can take place, creating a chain reaction releasing
heat. The heat is used to turn water into steam, that, in turn, spins a
turbine that generates electricity. Nuclear power was used to generate
about 21% of all the Country's electricity in 2008.

Renewable Energy Sources Make Up the Rest

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=hydropower_home" 
Hydropower , the source for 6% of U.S. electricity generation in 2008,
is a process in which flowing water is used to spin a turbine connected
to a generator. There are two basic types of hydroelectric systems that
produce electricity. In the first system, flowing water accumulates in
reservoirs created by dams. The water falls through a pipe called a
penstock and applies pressure against the turbine blades to drive the
generator to produce electricity.

In the second system, called run-of-river, water is diverted from a
river using a relatively low dam or weir into penstocks and turbines.
The dam does not store a large volume of water in a reservoir.
Run-of-river power plants are more dependent on river flows than hydro
plants with reservoirs for storing water which can produce electricity
even when natural river flows are low.

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=biomass_home" 
Biomass  is material derived from plants or animals (i.e. biogenic) and
includes lumber and paper mill wastes; food scraps, grass, leaves,
paper, and wood in municipal solid waste (garbage); and forestry and
agricultural residues such as wood chips, corn cobs, and wheat straw.
These materials can be burned directly in steam-electric power plants,
or converted to gas that can be burned in steam generators, gas
turbines, or internal combustion engine-generators. Biomass accounts for
about 1% of the electricity generated in the United States. 

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=wind_home"  Wind
power  is produced by converting wind energy into electricity.
Electricity generation from wind has increased significantly in the
United States since 1970, but wind power remains a small fraction of
U.S. electricity generation, about 1%. 

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=geothermal_home" 
Geothermal power  comes from heat energy buried beneath the surface of
the earth. In some areas of the United States, enough heat rises close
to the surface of the earth to heat underground water into steam, which
can be tapped for use at steam-turbine plants. This energy source
generated less than 1% of the electricity in the Country in 2008.

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/print.cfm?page=solar_home" 
Solar power  is derived from energy from the sun.  There are two main
types of technologies for converting solar energy to electricity:
photovoltaic (PV) and solar-thermal electric. PV conversion produces
electricity directly from sunlight in a photovoltaic (solar) cell.
Solar-thermal electric generators concentrate solar energy to heat a
fluid and produce steam to drive turbines. In 2008, less than 1% of the
Nation's electricity was from solar power.

Also on Energy Explained

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_use" 
Use of Electricity  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_facto
rs_affecting_prices"  Factors Affecting Electricity Prices  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=nuclear_use"  Use
of Nuclear Power  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_homes" 
Energy Use in Homes  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_commerc
ial"  Energy Use in Commercial Buildings 

Learn More

  HYPERLINK
"http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html" \l
"change"  Electric Power Industry Overview 2007  —
http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html#change 

  HYPERLINK "http://www.eei.org/"  Edison Electric Institute  —
http://www.eei.org/ 

  HYPERLINK "http://www.appanet.org/"  American Public Power Association
 — http://www.appanet.org/ 

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html"  How
clean is my electricity?  —
http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html 

  HYPERLINK
"http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.htm
l"  Renewable Energy Information  —
http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.html

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html" 
Hydroelectricity  —
http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html

 

Last Updated: February 2, 2010

http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_in_the
_united_states

Electricity in the United States – Generation, Sales & Capacity

There is more than one way to size up U.S. electricity. Looking at how
much and from what sources electricity is generated (“generation”)
is only one piece of the puzzle. Electricity sales and capacity also
provide important perspectives on U.S. electricity: 

Generation — The amount of electricity produced over a period of
time.  

Sales — The amount of electricity sold to customers over a period of
time.  

Capacity — The maximum level at which electric power can be supplied
at a point in time. 

Electricity Generation

 

Click to enlarge »

 

  HYPERLINK "http://www.eia.doe.gov/cneaf/electricity/epa/figes1.xls" 
Data for this figure 

About 90% of U.S. electricity is generated by three fuels: coal, natural
gas, and nuclear: 

Coal — 48.2% 

Natural Gas — 21.4% 

Nuclear — 19.6% 

Hydroelectric — 6.0% 

Other Renewables — 3.1% 

Petroleum — 1.1% 

Net generation of electricity fell to 4,119 billion kilowatthours (kWh)
in 2008 from 4,157 billion kWh in 2007. A combination of weak economic
activity and reduced summer electricity demand for cooling contributed
to the 0.9% decrease in net generation.

Electricity Sales 

U.S. electricity sales to customers totaled nearly 3,765 billion
kilowatthours (kWh) in 2008, a 0.8% decline over 2007. 

Sales to each customer class in 2007 totaled: 

Residential — 1,380 billion kWh (37% of electricity sold) 

Commercial — 1,336 billion kWh (36%) 

Industrial — 1,009 billion kWh (27%) 

Transportation — 8 billion kWh (0.2%) 

Sales by each kind of provider in 2008 totaled: 

Investor-owned electric utilities — 60% of electricity sold 

Public utilities — 15% 

Energy-Only Providers — 14% 

Cooperatives — 11% 

Federal Power Marketing Authorities — 1% 

Electricity Capacity 

 

Click to enlarge »

 

  HYPERLINK "http://www.eia.doe.gov/cneaf/electricity/epa/figes2.xls" 
Data for this figure 

Electricity capacity is essentially the maximum level at which electric
power can be supplied at a point in time. 

Sufficient capacity is important, because enough electricity must always
be produced to meet demand at every moment. 

At most times, many power plants are not generating electricity at their
full capacity. There are three major types of generating units that vary
by intended usage: 

A baseload generating unit is normally used to satisfy all or part of
the minimum or base load of the system and, as a consequence, produces
electricity at an essentially constant rate and runs continuously.
Baseload units are generally the newest, largest, and most efficient of
the three types of units. 

A peakload generating unit, normally the least efficient of the three
unit types, is used to meet requirements during the periods of greatest
or peak load on the system. 

An intermediate-load generating unit meets system requirements that are
greater than base load but less than peak load. Intermediate-load units
are used during the transition between baseload and peak load
requirements. 

Since the late 1990s, natural gas has been the fuel of choice for the
majority of new generating units. Natural gas now accounts for about 40%
of total generating capacity.

Also on Energy Explained

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_use" 
Use of Electricity  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_facto
rs_affecting_prices"  Factors Affecting Electricity Prices  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=nuclear_use"  Use
of Nuclear Power  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_homes" 
Energy Use in Homes  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_commerc
ial"  Energy Use in Commercial Buildings 

Learn More

  HYPERLINK
"http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html" \l
"change"  Electric Power Industry Overview 2007  —
http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html#change 

  HYPERLINK "http://www.eei.org/"  Edison Electric Institute  —
http://www.eei.org/ 

  HYPERLINK "http://www.appanet.org/"  American Public Power Association
 — http://www.appanet.org/ 

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html"  How
clean is my electricity?  —
http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html 

  HYPERLINK
"http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.htm
l"  Renewable Energy Information  —
http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.html

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html" 
Hydroelectricity  —
http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html

 

Last Updated: February 2, 2010

http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_in_the
_united_states

Electricity in the United States – "Top 10"

Largest Utility Plants by Net Generation 

(2008 data)

Rank

Operator Name

Facility Name

State

Net Generation 

(megawatthours)

1

Arizona Public Service Co

Palo Verde

AZ

29,250,496 

2

Tennessee Valley Authority 

Browns Ferry

AL

24,919,416 

3

Georgia Power Co

Scherer 

GA

24,348,774 

4

U.S. Bureau of Reclamation 

Grand Coulee 

WA

22,315,158 

5

Georgia Power Co 

Bowen

GA

22,233,216 

6

Duke Energy Indiana Inc 

Gibson 

IN

21,903,413 

7

STP Nuclear Operating Co 

South Texas Project 

TX

21,492,749 

8

Alabama Power Co 

James H Miller Jr 

AL

21,372,796 

9

Progress Energy Florida Inc 

Crystal River 

FL

21,260,604 

10

Ohio Power Co 

General James M Gavin 

OH

21,102,132 

Largest Utility Plants by Capacity

 

Rank

Operator Name

Facility Name

State

Summer Capacity

(Megawatts)

1

U.S. Bureau of Reclamation

Grand Coulee

WA

7,079

2

Arizona Public Service Co

Palo Verde

AZ

3,942

3

Florida Power & Light Co

Martin

FL

3,814

4

NRG Texas LLC

W A Parish

TX

3,667

5

Georgia Power Co

Scherer

GA

3,405

6

Florida Power & Light Co

Turkey Point

FL

3,330

7

Tennessee Valley Authority

Browns Ferry

AL

3,274

8

Georgia Power Co

Bowen

GA

3,254

9

Progress Energy Florida Inc

Crystal River

FL

3,171

10

Duke Energy Indiana Inc

Gibson

IN

3,131

 

Also on Energy Explained

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_use" 
Use of Electricity  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_facto
rs_affecting_prices"  Factors Affecting Electricity Prices  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=nuclear_use"  Use
of Nuclear Power  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_homes" 
Energy Use in Homes  

  HYPERLINK
"http://www.eia.doe.gov/energyexplained/index.cfm?page=us_energy_commerc
ial"  Energy Use in Commercial Buildings 

Learn More

  HYPERLINK
"http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html" \l
"change"  Electric Power Industry Overview 2007  —
http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html#change 

  HYPERLINK "http://www.eei.org/"  Edison Electric Institute  —
http://www.eei.org/ 

  HYPERLINK "http://www.appanet.org/"  American Public Power Association
 — http://www.appanet.org/ 

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html"  How
clean is my electricity?  —
http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html 

  HYPERLINK
"http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.htm
l"  Renewable Energy Information  —
http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.html

  HYPERLINK
"http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html" 
Hydroelectricity  —
http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html

 

Last Updated: June 10, 2010

http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_in_the
_united_states