Indiana Michigan nears permit for Rockport Unit 1 SCR project

The Indiana Office of Air Quality (OAQ) is taking comment until Jan. 31 on a draft air permit revision allowing the Indiana Michigan Power unit of American Electric Power (NYSE: AEP) to install a new air emissions control on one of the two, 1,300-MW units at the coal-fired Rockport plant.

The permit revisions cover the installation of a Selective Catalytic Reduction (SCR) NOx control system on Unit 1, and associated anhydrous ammonia handling equipment.

The following is a list of the modified emission unit(s) and pollution control device(s) on Unit 1:

  • One pulverized coal opposed wall fired dry bottom boiler, identified as MB1 (Main Boiler 1), with construction commenced in 1977 and completed in 1984, with a design heat input capacity of 12,374 million Btu per hour, with an electrostatic precipitator (ESP) system for control of particulates. Low NOX burners, and an overfire air (OFA) system have been installed and Selective Catalytic Reduction permitted in 2015 for NOX control. One powdered activated carbon (PAC) injection system, identified as activated carbon injection (ACI), permitted in 2008, 2010 and 2013, with a unit maximum capacity of injecting 4,000 pounds of halogenated or non-halogenated activated carbon per hour into the exhaust ductwork for Boiler 1 (MB1) from a dedicated silo(s). One dry sorbent injection (DSI) system, identified as DSI-U1, permitted in 2013, with a design injection capacity of 20,000 pounds of Sodium Bicarbonate per hour into the exhaust ductwork for MB1.

In February 2013, Indiana Michigan Power submitted an application to the Indiana Department of Environmental Management’s OAQ relating to the construction of new DSI systems for Units 1 and 2, the replacement of the Unit 1 Ash silo Bin Vent Filters, separator strings, and Unit 2 Separator Strings on three of the four silos, along with modifications to the design and operation of the existing landfill to dispose of the additional combustion waste generated by the DSI systems and changes to the ACI Systems and the changes in the classification of the material being disposed.

Provisions associated with the changes to the DSI systems, modifications to the Activated Carbon Systems, Ash Handling modifications, and landfill modifications are already incorporated into the Title V Permit as it exists today. The emission changes directly attributed to this project will begin as the Unit 1 SCR system is placed in service, which is planned for the second half of 2017.

Utility says the SCR cheaper than shutting this unit, replacing with gas capacity

Indiana Michigan Power has found it to be way less expensive to install SCR for NOX control on Rockport Unit 1 instead of replacing that 1,300 MW of capacity with new generation, much of it gas-fired. Indiana Michigan Power on Aug. 14, 2014, applied at the Indiana Utility Regulatory Commission for approval of the Rockport Unit 1 SCR project.

Paul Chodak III, President and Chief Operating Officer of Indiana Michigan Power (I&M), said the SCR under a consent decree with the federal government needs to be installed on Unit 1 by Dec. 31, 2017, which allow the unit to operate after that date.

Chodak noted that in 2014, I&M’s generation portfolio will consist of the two-unit 2,600-MW Rockport Plant, the Tanners Creek coal plant, the Cook Nuclear Plant, six run-of-the-river hydro plants and Power Purchase Agreements with Fowler Ridge and Wildcat Wind. In 2015, I&M’s generation portfolio will add 200 MW of wind energy from the Headwaters Wind Farm and will be reduced by the closure of the Tanners Creek coal plant due to that same federal consent decree that requires the Rockport Unit 1 SCR project.

That case was still pending at the Indiana URC as of Jan. 5. In Dec. 19 rebuttal testimony filed at the commission, Chodak wrote: “I&M will incur substantial costs as a result of a federally-mandated Rockport Unit 1 SCR Project as a joint investor in the Compliance Project that will allow Rockport Unit 1 to continue to be available to provide low-cost electricity to our customers. Yet, the [Office of the Utility Consumer Counselor] and the [Indiana Industrial Group] urge the Commission to deny I&M the opportunity to timely recover a significant amount of the federally-mandated costs. Moreover, the OUCC and the IG propose to prolong the recovery of depreciation expense and risk the consequences that a delay in uncertain times may have on I&M and its customers. The timely recovery of environmental compliance costs is the goal of the public policy established by the legislature. Accordingly, I&M should be authorized by the Commission to advance that goal, notwithstanding the positions of the OUCC and IG.”  

The Rockport plant is located in Spencer County, Ind., and consists of two nominally-rated 1,300-MW coal-fired generating units. Rockport Unit 1 was placed in service in 1984 and Unit 2 in 1989, which is relatively young for coal-fired generation.

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.