The US Energy Information Administration reports that after 54 years of providing power to Pennsylvania and New York, the Homer City Generating Station in Pennsylvania will close by July 2023, according to the plant’s owner. The 1888 MW plant began generating electricity in 1969, when Units 1 and 2 entered service. Unit 3 was added in 1977.

Coal plants across the country are retiring, with US coal-fired capacity contracting from 313 GW in 2005 to around 196 GW today. The Homer City plant was designed to provide base load power, but recently coal plants have struggled to effectively compete in competitive US power markets against newer, more efficient, natural gas-fired, combined-cycle power plants.

The Homer City plant was built near coal reserves and included what was then a high-capacity (345 kV) transmission line to service areas in western New York and eastern Pennsylvania. For 30 years, the plant operated almost continuously, achieving a utilisation rate, ie a capacity factor, near 90%.

In 1999, the Homer City plant sold for $1.8 billion, corresponding to a period when Pennsylvania was deregulating its energy market. At that time, coal-fired generation accounted for about 53% of the nation’s power supply; natural gas only accounted for about 12%. Since then, those roles have nearly reversed; natural gas is now the source of 40% of the electricity in the United States, and coal has dropped to 20%.

The market landscape changed for the Homer City plant at the turn of the century. New emissions standards for power plants under the Clean Air Act required the plant to install FGD scrubbers on Unit 3 in 2001 and on Units 1 and 2 in 2014. Pollution control upgrades in 2014 cost the plant owners a reported $570 million. Ownership of the plant changed after bankruptcy in 2017.

Driven by the ramp up of drilling and fracking to produce natural gas from the Marcellus and Utica shale formations in the region, many new natural gas fired power plants were built in Pennsylvania. As new natural gas-fired plants were built, the Homer City plant was dispatched more intermittently for load following instead of for base load. This change increased annual maintenance costs, on top of the debt incurred from the pollution control upgrades. The capacity factor dropped to 20% in 2022, contributing in the decision to retire the plant.

Image: The generating towers of the Homer City Generating Station in Pennsylvania (courtesy of Wikimedia Commons)