Indianapolis Power & Light on Dec. 26 applied for Indiana Utility Regulatory Commission approval for the latest series of air emissions control projects for its coal-fired capacity.
The application was filed in an environmental cost passthrough proceeding that involves getting approval for ongoing costs of emissions projects already approved by the commission.
Michael Smith is IPL’s Manager, Engineering & Project Management for three generating stations; Harding Street (HSS), Petersburg (PE) and Eagle Valley (EV).
Asked what capital maintenance projects IPL has planned for the next six-month period, Smith wrote: “IPL intends to install the HSS7 NOx monitors, replace certain SCR expansion joints and coat the scrubber absorber tanks during the Spring 2014 outage. At Petersburg, IPL anticipates replacing two layers of the Petersburg Unit #3 (‘PE3’) scrubber demister packing in Spring 2014, and will likely consider the purchase of a new SCR catalyst layer for PE2 in 2014 due to the condition of the middle layer removed during the 2013 PE2 major outage. It has not been determined yet whether this will be a ‘regenerated’ layer or a ‘new’ layer. IPL is working to add this to the 2014 budget and is evaluating installation in the Spring 2015 PE2 tie-in outage of the new bag house for Mercury and Air Toxies Standards (‘MATS’) compliance.”
As for a previously approved NOX compliance program, Smith said that all of the projects approved are in-service.
There were two Multi-Pollutant Plan projects approved in a prior case. The enhancements project to the existing flue gas desulfurization (FGD) system on PE3 have been completed and the project entered service on June 24, 2006. The performance of the upgraded scrubber has exceeded the original SO2 design emission target of 0.4 lbs SO2/MMBTU as the current emissions from PE3 are less than 0.2 lbs S02/MMBTU. This better than expected performance will likely result in lower future SO2 compliance costs as fewer SO2 emissions allowances will be consumed on PE3. The second project, the HSS7 FGD, went into service in September 2007. All construction completion activities have been completed.
Angelique Oliger, Director of Environmental Policy for AES US Services LLC, offered an update on MATS compliance work. IPL is a unit of AES Corp. (NYSE: AES).
The MATS rule requires compliance by April 16, 2015. However, in December 2012, the Indiana Department of Environmental Management (IDEM) issued a compliance extension, allowing the Eagle Valley coal-fired units, the Harding Street coal-fired units, and two Petersburg coal units (Units 3 and 4) one additional year, or until April 16, 2016, for compliance. Then, on Feb. 8, IDEM granted a three-month compliance extension for Petersburg Unit 2 to July 16, 2015.
Further, EPA may allow a fifth year to come into compliance for reliability critical units through an “Agreed Order” process. IPL is currently working with the Midcontinent Independent System Operator (MISO) to determine if the IPL units are critical to reliability.
IPL plans to retrofit the largest five coal units (Petersburg Units 1-4 and Harding Street Unit 7) with environmental controls to meet the MATS requirements. These units are each equipped with flue gas desulfurization systems to fully scrub SO2, and three have selective catalytic reduction (SCR) technology to control NOx. These controls also assist in the removal of MATS-regulated emissions – including acid gases, mercury and non-mercury metal hazardous air pollutants, Oliger noted.