Homer City Generating Station is a decommissioned 2-GW coal-burning power station near Homer City, in Indiana County, Pennsylvania, USA. It is owned by hedge funds and private equity firms and is operated by NRG Energy. Units 1 and 2, rated at 660 MWe, began operation in 1969. Unit 3, rated at 692 MWe nameplate capacity, was launched in 1977. It employed about 124 people.

During the 2010s, it underwent two bankruptcies within five years. On April 3, 2023, Homer City Generation announced a decision to shut down the power plant and be offline by June 2, 2023.

The station is located in Center Township, Indiana County, Pennsylvania, occupying approximately 2,400 acres (9.7 km). The site also includes the 1,800-acre (7.3 km) Two Lick Reservoir, a water conservation facility which is operated by the station.

From there, the Black Lick enters the Conemaugh River, which goes on to meet the Loyalhanna River, creating the Kiskiminetas River, before entering the Allegheny River.

With diminishing local coal and mines to support it, the train track that ran through Indiana University of Pennsylvania had reopened and supplies were brought in by train.

Until its construction in the 1960s by the Pennsylvania Electric Co. (PenElec) and others, much of the property was owned by the George family. In 1969, Units #1 and #2 began operation, while Unit #3 began operating in 1977.

Six workers were injured on February 10, 2011, when a six-inch, high-pressure steam pipe in Unit 1 ruptured and caused an explosion on the sixth floor of a building. Three of the men were airlifted to the Western Pennsylvania Hospital burn center, and three were treated locally. The incident was investigated by the Occupational Safety and Health Administration.

In 2001, affiliates of General Electric bought the plant from Edison International, and subsequently leased it back to them. In 2011, Edison failed to secure financing to add pollution-control devices and announced plans to transfer full control to General Electric. On February 29, 2012, Edison took a $1 billion impairment charge related to the Homer City plant and several other coal-fired power plants. At the end of 2012 full control of the plant was transferred back to General Electric, which hired an NRG affiliate to operate it.

In early 2017, the plant filed for bankruptcy protection.

In early 2022 the facility's owners announced that they were considering deactivating some of its units. The owners initially decided to continue operation, but on April 3, 2023 Homer City Generation announced a decision to shut down the power plant and be offline by June 2, 2023.

The power plant was permanently decommissioned on July 1, 2023.

The plant was a major polluter, ranking highly both nationally and within the state; Pennsylvania has ranked it the #2 polluter in the state. Like other coal fired power plants of this scale, Homer City Generating Station released huge amounts of carbon dioxide as well as mercury, sulfur dioxide, and other toxic or damaging chemicals. Pollution control equipment was added in 1998 to reduce mercury output. In 2012, General Electric had scrubbers installed to further reduce the plant's emissions.

• According to the American environmental activist group Environmental Working Group, Homer City Generating Station produced a total of 2,963 pounds (1,344 kg) of mercury in 1998 alone.

According to Public Citizen: "The plant ranks #33 in the nation for total CO₂ emissions, contributing 13,745,174 tons of the pollutant primarily responsible for global warming to our atmosphere." The organization Carbon Monitoring for Action (CARMA) reported in 2007 that this plant emitted 12,800,000 tons of CO₂ and also ranked the facility as 33rd largest CO₂ emitter in the United States.

• In 1995, Homer City discharged 127,383 pounds (57.780 metric tons) of SO₂.
• In 2003, Homer City discharged 151,262 pounds (68.611 metric tons) of SO₂ and was ranked the fourth-largest SO₂ polluter in the nation.
• In 2005, the facility was ranked as the nation's sixth-highest SO₂ polluter as it discharged 119,771 pounds (54.327 metric tons) of SO₂ that year.

In 2007, the Pennsylvania Department of Environmental Protection (DEP) fined the owners of the Homer City electricity generating station, EME Homer City Generation LP, $200,000 for violating the Pennsylvania Clean Streams Law. The station exceeded its permitted effluent standards for selenium, total suspended solids, and biochemical oxygen demand in its wastewater discharges, and allowed unpermitted discharges of stormwater associated with its flue-gas desulfurization scrubbers.

Homer City's three coal boilers installed Selective Catalytic Reduction to reduce ozone-forming NO_x emissions in 2000 and 2001. This technology produced up to an 83% reduction in NO_x emissions in subsequent years. Since the optimum years of 2005-06, emissions have begun to creep back up towards what they were before the installation of this technology. During the summer of 2012 plant emissions of NO_x doubled over the 2005-06 period from 2,300 tons to 4,500 tons, even as electrical generation fell by 30%. Through this same period, the price of natural gas, which competes with coal as a fuel for electrical generation, fell by some 60%. Through the 2013 summer ozone season, this trend in rising emission rates continued resulting in over 6,300 tons of NO_x emissions in excess of what could have been achieved had the plant operated at its previously demonstrated optimum rates seen in 2005-06.

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The plant's Unit 3 has a 371 m (1,217 ft) tall chimney, which was built in 1977. This chimney is currently the third-tallest chimney in the world, the second-tallest in North America, and the tallest in the United States. On clear days, it is possible to spot the chimney from as far south as Greensburg, Pennsylvania, and as far east as Ebensburg, Pennsylvania. The chimney is no longer in use, as the gas flow from Unit 3 has been bypassed through a newer flue gas treatment system installed in 2002.

• List of largest power stations in the United States
• List of power stations in Pennsylvania

• 2005 toxic output numbers
• Post Gazette article
• Pennsylvania plant rankings