AEP’s Oklahoma utility completes retrofits on one coal unit, readies shutdown of another

Public Service Co. of Oklahoma (PSO) said Feb. 23 that it has completed a major project at its Northeastern Station (NES) Unit 3, with the coal-fired unit having begun operating with newly-added environmental controls.

Completion of the project is a significant milestone in a years-long effort to develop and carry out a plan to meet U.S. Environmental Protection Agency (EPA) rules addressing regional haze and other pollutants. PSO President and Chief Operating Officer Stuart Solomon said the upgrades permit the company to meet federal requirements and are a key part of PSO’s plan to provide cleaner power supplies for its customers.

Said Solomon: “Along with the continuing addition of renewables to our energy mix, PSO is providing cleaner power supplies and improving air quality in Oklahoma, while maintaining excellent reliability and low prices for our customers.”

In April 2012, PSO announced it had entered in an agreement in principle with the state of Oklahoma, EPA, and the Sierra Club for its Environmental Compliance Plan (ECP), which was primarily focused on compliance at the company’s two coal-fired units at NES.  The ECP’s main feature was the addition of significant new environmental controls to NES Unit 3, allowing it to operate for another 10 years, before its eventual retirement in 2026. The plan also provides for the shutdown in April 2016 of the coal-fired Unit 4 at NES.

PSO’s ECP also involved upgrades to reduce NOx emissions at several gas-fired units.

New environmental controls for NES Unit 3 include Activated Carbon Injection (ACI) to capture mercury in the flue gas, Dry Sorbent Injection (DSI) to reduce acidic gases and SO2, and a Fabric Filter (also called a bag house) to trap particulate matter.

Gary Knight, PSO vice president–Generation, said: “Collaboration between plant personnel, engineering and project management, as well as the many contractors involved, is what led to this successful outcome.”

PSO will be replacing the power from the soon-to-close NES Unit 4 with purchased power from a gas-fired Calpine (NYSE: CPN) generating facility east of Tulsa, and with additional supplies of wind energy from new contracts that went into effect at the beginning of 2016.

Units 1 and 2 at Northeastern are gas-fired facilities with a combined capacity of about 852 MW, while the coal-fired Units 3 and 4 are each about 460 MW (net summer) in size.

PSO, a unit of American Electric Power (NYSE: AEP), is an electric utility company serving more than 540,000 customers in eastern and southwestern Oklahoma. Based in Tulsa, PSO has 4,256 MW of generating capacity, and is a significant provider of wind energy in the state.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.