State Line Generating Plant

State Line Generating Plant
State Line Generating Plant
Country	United States
Coordinates	41°42′27″N 87°31′16″W
Status	Active
Commission date	Unit 3: December, 1955 Unit 4: May, 1962
Decommission date	Unit 1: 1978 Unit 2: 1979
Owner	Dominion
Operator	Chicago District Electric Generating Corporation
Employees	120
Power generation
Nameplate capacity	613.8 MW
External links
Commons	Related media on Commons

The State Line Generating Plant is a coal-fired electrical generating station located on the coast of Lake Michigan, bordering the state line separating Indiana from Illinois but within the corporate limits of Hammond, Indiana. As of 2008–2009, it has a year-round capacity of 515 megawatts.

Most of the plant's exterior and some of its interior infrastructure date back to its date of original operation in 1929, making this plant one of the oldest large-scale urban electrical generating stations in the United States. The plant's age means that it generates more toxic waste, such as airborne mercury and nitrogen oxides, than most other U.S. generating plants. Historically owned and operated by Commonwealth Edison, the State Line Generating Plant is currently owned and operated by Dominion Resources. It is a National Historic Mechanical Engineering Landmark.

History

Samuel Insull

The State Line Generating Plant was built in 1926-1929 under the orders of industrial magnate Samuel Insull. Insull, who led a holding company that controlled Chicago's Commonwealth Edison electric utility, dedicated his working life to the implementation of economies of scale in the generation and supply of electricity.

During the 1920s, many residents of Greater Chicago had signed up to receive electrical service for the first time. Generating plants throughout the metropolitan area had developed the capacity to produce 1,310 megawatts of power to serve 1,300,000 customer households. At the same time, however, it was expected that demand for electricity would further increase. In particular, inhabitants of many rural areas throughout the United States, including rural areas adjacent to greater Chicago, did not yet have electrical service in 1929.

In addition to increased demand for electricity from households for purposes such as lighting and appliances, Insull expected substantial increases in demand for electricity from industrial-scale purchasers. In particular, Insull's holding companies also controlled the Chicago South Shore and South Bend, an electric railroad that ran near the site of the State Line Power Plant.

In order to fulfill the increased demand for electricity that Insull's engineers told him was expected and which he concurred was going to occur, the Insull holding companies constructed the State Line Power Plant and the Unit 1 generator within the plant. With a capacity of 208 megawatts, Unit 1 upon its operational date in 1929 was the largest turbine generator constructed up to that time. The turbine plant was built by General Electric at their plant in Schenectady, New York, and carried to Hammond for assembly. Its operation increased total Chicago-area electrical generation capacity by more than 15%, to 1,518 megawatts.

Insull's optimism was sufficient that he ordered that the State Line Power plant be constructed on a scale sufficient to allow for the insertion of further turbines in the building. Commonwealth Edison's goal was to eventually insert enough capacity into State Line to generate more than 1,000 megawatts of power - which would make the State Line Power Plant the world's first one-gigawatt plant.

Unfortunately, the 1929 infrastructure projects of Insull's holding companies were financed with highly-leveraged junk bonds. The Insull firms could not survive the shock of the Great Depression, and Insull and his investors suffered devastating financial losses. However, the State Line Power Plant had been professionally engineered and constructed, and continued to operate through the Depression, World War II, and into the postwar years.

Today

Commonwealth Edison expanded the State Line Power Plant according to plan, with Unit 2 going into operation in 1938, Unit 3 in 1955, and Unit 4 in 1963.

As a result of various factors, including the advent of nuclear power and the passage of the Clean Air Act, by the late 20th and early 21st centuries the State Line Power Plant was entering the latter phase of its useful life. The historic Unit 1 turbine was taken out of service in 1978, followed by Unit 2 in 1979. Because these two units are permanently out of service, they should not be confused with the turbine units now operating within the same building that have been renamed as Units 1 and 2.

As of 2010, the State Line Power Plant's two newer coal-fired units, historically Units 3 and 4 (but renamed as Units 1 and 2) continued to operate with a maximum capacity of 515 megawatts. The plant employed approximately 120 full-time employees.

The State Line Power Plant's age meant that it has not been fitted with many of the pollution control equipment that is mandated on more modern generating plants. Instead, State Line's operations are grandfathered, giving the plant the right to vent nitrogen oxides, airborne mercury, and sulphur dioxide into the air. According to a September 2010 article in the Chicago Tribune, the State Line Power Plant is described as one of the greatest single point-source contributors to the Chicago area's ongoing noncompliant status under the Clean Air Act.