Keystone Power Plant
Encyclopedia
The Keystone Generating Station is a 1,711 MW
baseload
coal
-fired power plant located on roughly 1500 acres (6.1 km²) at 40°39′36"N 79°20′27"W, in Plumcreek Township, southeastern Armstrong County, Pennsylvania
near Crooked Creek
, just west of Shelocta, Pennsylvania
.
The facility consists of two steam turbine
s, which began commercial operation in 1967 and 1968, and four cooling tower
s.
The main turbines run on steam
produced by twin 850 MW boiler
s, each as tall as a 14-story building. The plant uses in excess of 4 million tons of coal a year. The plant ranks among the best in the US in terms of availability among coal plants of the same size.
Each unit is a Westinghouse cross-compound dual steam turbine-generator operating at supercritical steam conditions. At the time Keystone was constructed, Units 1 and 2 were the largest generating units in the world. Keystone was the first plant to be constructed away from a significant source of cooling water. The Keystone Reservoir was constructed on the North Branch of Plum Creek, a tributary of Crooked Creek to provide a constant source of cooling water for the plant's thermodynamic cycle year round. The cooling tower system at Keystone marks one of the most significant of early environmental controls on large power plants in the United States (thermal pollution of waterways was one of the first types of pollution to experience significant controls).
Since the plant's initial commissioning, several environmental control systems have either been upgraded or installed. These include modifications to the electrostatic precipitator
s, the addition of an ammonia
flue gas
conditioning system to improve precipitator performance, and a low/NOx
burner system to reduce the oxides of nitrogen (NOx) emissions. A Selective Catalytic Reactor
(SCR) further reduces the NOx emissions. In 2009 a wet flue gas desulfurization
system was put in place to reduce sulfur dioxide and heavy metal emissions. The plant has a continuous emissions monitoring system in the stack which must adhere to very rigid accuracy and reliability requirements established by the Commonwealth of Pennsylvania.
A consortium of mid-atlantic power companies owns the plant. PSEG Fossil owns a 22.84 percent share (391 net MW with peaker), while Reliant Resources, operates it. The plant is basically a twin of the Conemaugh Generating Station
, also partially owned by PSEG Fossil.
Key Facts:
Location: Shelocta, PA
MW: 1,711
Fuel: Coal
Commercial Operation: Unit 1: 1967, Unit 2: 1968
Ownership: 22.84% PSEG Fossil
from the flue gas
.
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
baseload
Base load power plant
Baseload is the minimum amount of power that a utility or distribution company must make available to its customers, or the amount of power required to meet minimum demands based on reasonable expectations of customer requirements...
coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
-fired power plant located on roughly 1500 acres (6.1 km²) at 40°39′36"N 79°20′27"W, in Plumcreek Township, southeastern Armstrong County, Pennsylvania
Armstrong County, Pennsylvania
Armstrong County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 68,941. It is located northeast of Pittsburgh and Allegheny County. Armstrong County was added to the Pittsburgh Metropolitan Statistical Area in 2003.The county seat is Kittanning...
near Crooked Creek
Crooked Creek (Allegheny River)
Crooked Creek is a tributary of the Allegheny River in both Armstrong and Indiana counties in the U.S. state of Pennsylvania.-Course:Crooked Creek joins the Allegheny River in both Bethel and Manor townships.- Tributaries :...
, just west of Shelocta, Pennsylvania
Shelocta, Pennsylvania
Shelocta is a borough in Indiana County, Pennsylvania, United States. The population was 127 at the 2000 census. The Keystone Generating Station is located to the west of the borough, in Plumcreek Township, Armstrong County, Pennsylvania.-Geography:...
.
The facility consists of two steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s, which began commercial operation in 1967 and 1968, and four cooling tower
Cooling tower
Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or in the case of closed circuit dry cooling towers rely...
s.
The main turbines run on steam
Steam
Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...
produced by twin 850 MW boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...
s, each as tall as a 14-story building. The plant uses in excess of 4 million tons of coal a year. The plant ranks among the best in the US in terms of availability among coal plants of the same size.
Each unit is a Westinghouse cross-compound dual steam turbine-generator operating at supercritical steam conditions. At the time Keystone was constructed, Units 1 and 2 were the largest generating units in the world. Keystone was the first plant to be constructed away from a significant source of cooling water. The Keystone Reservoir was constructed on the North Branch of Plum Creek, a tributary of Crooked Creek to provide a constant source of cooling water for the plant's thermodynamic cycle year round. The cooling tower system at Keystone marks one of the most significant of early environmental controls on large power plants in the United States (thermal pollution of waterways was one of the first types of pollution to experience significant controls).
Since the plant's initial commissioning, several environmental control systems have either been upgraded or installed. These include modifications to the electrostatic precipitator
Electrostatic precipitator
An electrostatic precipitator , or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas using the force of an induced electrostatic charge...
s, the addition of an ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
flue gas
Flue gas
Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants...
conditioning system to improve precipitator performance, and a low/NOx
NOx
NOx is a generic term for the mono-nitrogen oxides NO and NO2 . They are produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures...
burner system to reduce the oxides of nitrogen (NOx) emissions. A Selective Catalytic Reactor
Selective catalytic reduction
Selective catalytic reduction is a means of converting nitrogen oxides, also referred to as with the aid of a catalyst into diatomic nitrogen , , and water, . A gaseous reductant, typically anhydrous ammonia, aqueous ammonia or urea, is added to a stream of flue or exhaust gas and is absorbed...
(SCR) further reduces the NOx emissions. In 2009 a wet flue gas desulfurization
Flue gas desulfurization
Sulfur dioxide is one of the elements forming acid rain. Tall flue-gas stacks disperse emissions by diluting the pollutants in ambient air and transporting them to other regions....
system was put in place to reduce sulfur dioxide and heavy metal emissions. The plant has a continuous emissions monitoring system in the stack which must adhere to very rigid accuracy and reliability requirements established by the Commonwealth of Pennsylvania.
A consortium of mid-atlantic power companies owns the plant. PSEG Fossil owns a 22.84 percent share (391 net MW with peaker), while Reliant Resources, operates it. The plant is basically a twin of the Conemaugh Generating Station
Conemaugh Generating Station
The Conemaugh Generating Station is a 1,711 MW baseload coal-powered plant located on , across the Conemaugh River from New Florence in Western Pennsylvania.The station generates enough electricity to light 17 million 100-watt bulbs...
, also partially owned by PSEG Fossil.
Key Facts:
Location: Shelocta, PA
MW: 1,711
Fuel: Coal
Commercial Operation: Unit 1: 1967, Unit 2: 1968
Ownership: 22.84% PSEG Fossil
Owners
(partial list of 78.26%)- Public Service Enterprise GroupPublic Service Electric and Gas CompanyPublic Service Enterprise Group , commonly known as PSEG, and originally known as the Public Service Corporation of New Jersey and then as the Public Service Electric and Gas Company, is a regulated, publicly owned gas and electric utility company in the state of New Jersey, United States. It is...
: 22.84% or 391 Megawatts - Constellation EnergyConstellation EnergyConstellation Energy, headquartered in Baltimore, Maryland, is an energy producer, trader, and distributor. The company operates over 35 power plants in 11 states under its operating company Constellation Commodities Group and/or Constellation Generation Group...
: 20.91% or 358 Megawatts - Reliant EnergyReliant EnergyRRI Energy, Inc. , based in Houston, Texas, United States, was an energy company that provided electricity to wholesale customers in the United States. The company was one of the largest independent power producers in the nation with more than 14,000 megawatts of power generation capacity across...
(operator): 16% or 274 Megawatts - PPL Montour LLC: 12.34% or 211 Megawatts
- NRG EnergyNRG EnergyNRG Energy, Inc. is an American energy company headquartered in West Windsor Township, New Jersey, near Princeton.-Electrical Power Generation Operations:...
: 3.7% or 63 Megawatts - Duquesne Light Holdings: 2.47% or 42.3 Megawatts (this part was previously owned by Atlantic City Electric)
Emissions
Keystone uses modern emissions management technologies to greatly reduce the station's environmental impact. The wet limestone scrubber system put into operation in late 2009 removes heavy metals and sulfur dioxideSulfur dioxide
Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...
from the flue gas
Flue gas
Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants...
.