Duke Energy Indiana, which in April retired the coal-fired Wabash River Units 2-5, has more recently decided to also retire the idled Wabash River Unit 6 instead of switching this coal-fired facility to natural gas.
John D. Swez, employed by Duke Energy Carolinas as Director, Generation Dispatch and Operations, supplied July 27 testimony to the Indiana Utility Regulatory Commission in a twice-yearly fuel cost case for Duke Energy Indiana. These are units of Duke Energy (NYSE: DUK).
He said that Wabash River Units 2-5 were retired on April 15, 2016. These units were granted a one-year extension of the April 2015 Mercury and Air Toxics Standards (MATS) compliance date due to the need for at least two of the four units to operate at any given time for transmission system reliability (in addition to Wabash River Unit 6, which also had a one-year MATS extension). Duke Energy Indiana employed a MISO offer strategy that prioritized availability and operation of the units to solve transmission reliability constraints. As a result, it generally held two of the four of Wabash River Units 2-5 in reserve shutdown available for emergency operation only.
Wabash River Unit 6 had a one-year MATS rule extension until April 15, 2016, after which time the unit suspended operation. Duke Energy Indiana had been evaluating the potential to convert Wabash River 6 from coal to natural gas. Swez added: “The Company has decided not to pursue this, and on June 7, 2016, Duke Energy Indiana submitted an Attachment Y notification to MISO requesting a decommissioning and retirement date of December 7, 2016 for Wabash River 6 (318 MW) as well as the Wabash River 7 (8 MW) diesel units. MISO is studying the decommissioning request and has not provided the conclusion to date.”
Wabash River Units 2-5 total approximately 350 MW, with Units 2-4 at 85 MW each, and Unit 5 at 95 MW.