Until its construction in the 1960s by the Pennsylvania Electric Co. 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. In 2001, affiliates of General Electric bought the plant from Edison, and subsequently leased it back to them. In 2011, Edison International 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.
A scrubber was added in 1998 which reduced mercury output. In 2012, General Electric, through contractors, began construction of anti-pollution control equipment known as "scrubbers" to further reduce the plant's emissions.
Sulfur dioxide (SO2) pollution
In 1995, Homer City discharged of SO2.
In 2003, Homer City discharged of SO2 and was ranked SO2 the fourth-largest SO2 polluter in the nation. The scrubbers that the plant is installing will make Homer City one of the nation's cleanest coal-fired power plants.
In 2005, the facility was ranked as the nation's sixth-highest SO2 polluter as it discharged only 119,771 pounds of SO2 that year.
Homer City's three coal boilers installed Selective Catalytic Reduction to reduce ozone-forming NOx emissions in 2000 and 2001. This technology produced up to an 83% reduction in NOx 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 NOx 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 NOx emissions in excess of what could have been achieved had the plant operated at its previously demonstrated optimum rates seen in 2005-06.
Architectural mention
The plant's Unit 3 has a 371 m 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.