The Indiana Department of Environmental Management is taking comment until Oct. 3 on a draft air permit that would allow Indianapolis Power & Light to shut the coal-fired capacity at its Eagle Valley plant and build a new gas-fired facility at the site.
“IPL Eagle Valley Generating Station is proposing to replace the current coal and oil fired electric generating units at Indianapolis Power and Light’s (IPL’s) Eagle Valley Generating Station (EVGS) with a state-of-the-art, highly efficient combined cycle combustion turbine generation facility,” said an agency notice. “The proposed combined cycle facility would include two nominal 192.5 Mega Watt (MW) combustion turbines with steam waste heat recovery to drive a nominal 271 MW steam turbine generator. The new facility would have a total nominal capacity of 656 MW (net). The exclusive fuel for the new combustion turbines will be natural gas.”
The plant site is located at Martinsville, Ind., in Morgan County. The new gas-fired facility would consist of:
- Two natural gas fired combustion turbine units each with a natural gas fired duct burner identified as EU-1 and EU-2, permitted in 2013, each with a total rated heat input capacity of 2,542 MMBtu/hr; with NOx emissions controlled by low combustion burner design and Selective Catalytic Reduction (SCR), and each with an oxidation catalyst system to reduce emissions of carbon monoxide (CO) and volatile organic compounds (VOCs), and exhausting to stacks S-1 and S-2. Each stack will have continuous emissions monitors (CEMS) for NOx.
- One natural gas fired Auxiliary Boiler, identified as emission unit EU-3, permitted in 2013, with a rated heat input capacity of 79.3 MMBtu/hr, equipped with low NOx burners(LNB) with flue gas recirculation (FGR) to reduce NOx emissions exhausting to stack S-3.
- One natural gas fired Dew Point Heater, identified as emission unit EU-4, permitted in 2013, with a rated heat input capacity of 20.8 MMBtu/hr exhausting to stack S-4.
The current Eagle Valley plant consists of:
- Two No. 2 fuel oil-fired boilers, identified as Unit 1 and Unit 2, constructed in 1949 and 1950, respectively, each with a design heat input capacity of 524 million Btu per hour (MMBtu/hr), both exhausting to stack 1-1.
- One tangentially-fired wet-bottom coal boiler (Unit 3), constructed in 1951, with a design heat input capacity of 524 MMBtu/hr, with an electrostatic precipitator (ESP) and flue gas conditioning system for control of particulate matter, exhausting to stack 2-1.
- One tangentially-fired dry-bottom coal fired boiler (Unit 4), constructed in 1953, with a design heat input capacity of 741 MMBtu/hr, with an ESP and flue gas conditioning system for control of particulate matter, exhausting to stack 2-1. Unit 4 is equipped with separated overfire air (SOFA) and low NOX burners (LNB) for control of NOX emissions, which were voluntarily installed and are not required to operate.
- One tangentially-fired dry-bottom coal boiler (Unit 5), constructed in 1953, with a design heat input capacity of 741 MMBtu/hr, with an ESP and flue gas conditioning system for control of particulate matter, exhausting to stack 3-1. Unit 5 is equipped with SOFA and LNB for control of NOX emissions, which were voluntarily installed and are not required to operate.
- One tangentially-fired dry-bottom coal boiler (Unit 6), constructed in 1956, with a design heat input capacity of 1,017 MMBtu/hr, with an ESP for control of particulates, exhausting to stack 3-1. Unit 6 is equipped with Closed-coupled Overfire Air (COFA) for control of NOX, which was voluntarily installed and is not required to operate. Unit 6 has also had low-NOX burners installed.
- One distillate oil-fired generator, identified as Unit PR-10, constructed in 1967, with a design heat input capacity of 28.4 MMBtu/hr, exhausting to stack PR10-1.
Agency also takes comment on Harding Street coal-to-gas conversions
IPL, a unit of AES Corp. (NYSE: AES), is also pursuing a revised Title V air permit for its Harding Street plant that would allow the conversion of two coal units to firing natural gas. The Indiana Department of Environmental Management is taking public comment until Sept. 16 on the draft version of the revised permit.
The planned coal-to-gas conversions involve Units 5 and 6 at Harding Street. The other coal unit at the plant, Unit 7, is scrubbed-equipped and in the utility’s plans for the long term.
The Indiana Utility Regulatory Commission on Aug. 14 approved $511m worth of new air controls for the “Big Five” coal units of IPL to meet air rules like the Mercury and Air Toxics Standards (MATS). IPL owns and operates 3,353 MW of nameplate capacity. Its Big Five consists of Petersburg Units 1-4 and Harding Street Unit 7. The Big Five are fully scrubbed and have fewer years of service compared to the other primarily coal-fired units in IPL’s fleet, which are due for retirement.
IPL in that case did not request approval of a control plan for its Small Six coal-fired units. These units are being evaluated separately and IPL is broadly looking at all options on a remaining life cycle basis. IPL said during the case that current analysis indicates that it is likely that the Eagle Valley coal plant will be fully retired ahead of MATS rule implementation, and that the coal-fired Harding Street Units 5 and 6 may be retired or repowered as gas-fired peakers.
These units represent 472 MW of net capacity in total. To replace this generation, in April 2013, IPL filed a petition and case-in-chief with the IURC seeking a certificate to build a 550 MW to 725 MW combined cycle gas turbine (CCGT) project at the Eagle Valley site and to refuel Harding Street Units 5 and 6 from coal to natural gas (106 MW net capacity each). The 656 (net) figure in the Eagle Valley draft permit fits within that given range for the new CCGT at Eagle Valley.
If approved, the Eagle Valley CCGT is expected to be placed into service in April 2017 and the refueling project is expected to be complete by April 2016. If Harding Street Units 5 and 6 are not refueled, they will likely need to be retired because it is currently not economical to install controls on those units to comply with MATS.