Chalk Point Generating Station

Chalk Point Generating Station
Company type	Power station
Industry	Electric power generation
Founded	1964
Headquarters	Eagle Harbor, United States
Area served	Maryland, United States
Products	Electricity
Owner	NRG Energy

The Chalk Point Generating Station is an electricity production facility owned by NRG Energy, situated near Eagle Harbor, Maryland along the Patuxent River. It operates units fueled by oil and natural gas. The plant's two coal-fired units were decommissioned by operator GenOn Energy Holdings in June 2021, a decision welcomed by environmental advocates but criticized for the absence of a comprehensive "Just Transition" strategy addressing the needs of displaced workers and the local community.

Individual Units

The station comprises Units 3 and 4, each rated at 659 MWe and powered by oil and natural gas, commissioned in 1975 and 1981 respectively. These units utilize natural draft cooling towers. Additionally, the facility includes seven combustion turbines under NRG's ownership and management:

Oil-powered GT1 and GT2 (installed in 1967 and 1974) with capacities of 16 MWe and 35 MWe.
Oil/gas-fueled GT3 through GT6 (commissioned in 1991), with ratings of 103, 103, 125, and 125 MWe respectively.
Unit SGT1, an oil/gas turbine generating 94 MWe, brought online in 1990 and acquired from Southern Maryland Electric Cooperative (SMECO) by NRG in 2015.

Together, these turbines have a combined nameplate capacity of 601 MWe.

The coal-fired components, Units ST1 and ST2, are dry-bottom, wall-fired steam plants with ratings of 364 MWe each. These units began operations in 1964 and 1965 but were retired in 2021.

History

Operations at Chalk Point commenced in 1964. Initially, all generating units were constructed by the Potomac Electric Power Company. Following Maryland’s electricity market restructuring, these assets were sold to Southern Company in December 2000. In April 2001, Mirant was spun off from Southern Company, inheriting Chalk Point. Mirant later merged into GenOn Energy in 2010, which itself was integrated into NRG Energy in 2012.

NRG initially intended to retire both Chalk Point and Dickerson Generating Stations by May 2017; however, Chalk Point continued functioning for at least ten more years. In August 2020, GenOn revealed plans to cease operations of the two coal-fired units by June 2021. While environmental groups and community stakeholders supported this closure, they expressed concern over Maryland’s failure to implement a Just Transition plan for workers and affected communities.

Fuel delivery

Coal deliveries to Chalk Point were facilitated by CSX Transportation trains operating on the Herbert Subdivision—a former Pennsylvania Railroad route accessed via Amtrak's Northeast Corridor. These trains were assembled at CSX’s Benning Yard located in Anacostia, Washington, DC.

Dispatch of electricity

The output from Chalk Point is managed and dispatched by the PJM Interconnection regional transmission organization.

Environmental impacts

According to a 2006 report from the U.S. Environmental Protection Agency (EPA), Chalk Point released over 21 pounds per megawatt-hour of sulfur dioxide (SO₂), ranking it as the nation’s 24th largest SO₂ emitter. It was also identified as the 43rd highest emitter of nitrogen oxides (NOx). In terms of carbon dioxide (CO₂) emissions, Chalk Point discharged approximately 4.7 million metric tons in 2010; this figure declined to around 0.6 million metric tons by 2019.

In August 2018, the Maryland Department of the Environment (MDE) required Chalk Point along with two other state power plants to meet updated federal wastewater regulations by November 2020. Previously, coal-fired units had been releasing arsenic and mercury under outdated permits dating back to the 1980s. Compliance with current standards was projected to reduce toxic metal discharges by up to 97%. These federal effluent regulations were established by EPA in 2015.

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