Generation Resources
IMPA’s portfolio of resources includes three coal-fired units in which the Agency has ownership interests, a coal-fired plant currently under construction, as well as seven combustion turbine units in which the Agency has full ownership. Click the photos below to learn more about each resource.
Gibson Station Unit 5 Trimble County Station
- Co-owned with Duke Energy Indiana - Co-owned with Louisville Gas & Electric
and Wabash Valley Power Association and the Illinois Municipal Electric Agency
- Total generating capacity of Unit 5 - 625 MW - Total coal generating capacity - 1274 MW
- IMPA owns 156 MW - IMPA owns 162 MW
Prairie State Energy Campus Combustion Turbines
- Total generating capacity - 1600 MW - IMPA owns seven units with a total capacity of 419 MW
- IMPA owns 200 MW - Three units in Anderson, two units in Richmond, two unit
- Mine-mouth coal-fired baseload generator in Indianapolis
- Owns 30 year coal reserve - Natural gas peaking units
Gibson Station Unit 5 
Gibson Unit 5 is a 625 MW coal-fired baseload generating facility located in southwestern Indiana. The unit was placed in service in 1982 and relies on high sulfur coal supplies predominantly from southern Indiana. Coal for Gibson Unit 5 is delivered to the plant by rail and truck and is purchased from several suppliers under contracts with varying terms.
Gibson Unit 5 is equipped with particulate, sulfur dioxide (SO2) and nitrogen oxide (NOX) removal facilities. Installation of a Selective Catalytic Reduction (SCR) system for NOX control was completed in 2004, and in 2008, Gibson Unit 5 upgraded its flue gas desulfurization system to increase SO2 removal efficiency.
IMPA has an 24.95% ownership interest, or approximately 156 MW, in Gibson Unit 5, which it jointly owns with Duke Energy and the Wabash Valley Power Association.
Back to top
Trimble
County Station Units 1 and 2
Trimble County Unit 1 is a 514 MW coal-fired electric generating unit located in Kentucky on the Ohio River approximately 20 miles southwest of Madison, Indiana. Trimble County Unit 1 was placed in service in 1990. IMPA has a 12.88% undivided ownership interest in Trimble County Unit 1, which is jointly owned by Louisville Gas & Electric Company (LG&E) and the Illinois Municipal Electric Agency (IMEA). Trimble County Unit 1 is equipped with particulate, SO2 and NOX removal facilities and utilizes high sulfur coal. Installation of a SCR for NOX control was completed in 2003. The SO2 removal facilities were upgraded in 2005 to increase removal efficiency.
Trimble County Unit 2 is a nominal 750 MW, supercritical steam unit constructed at the same site as Trimble County Unit 1. Trimble County Unit 2 was placed in service in 2011. IMPA has a 12.88% ownership interest in Trimble County Unit 2, which is approximately 100 MW. LG&E, Kentucky Utilities, and IMEA also hold ownership interests in the unit. Trimble County Unit 2 includes state-of-the-art emissions control, including a SCR, a dry electrostatic precipitator, a bag house; wet flue gas desulfurization; and a wet electrostatic precipitator. The plant is designed to comply with all current emissions regulations and permit conditions and is well prepared to comply with upcoming federal regulations.
The design for Trimble County Unit 2 provides for fuel flexibility enabling the use of lower-cost or low sulfur fuels in the unit’s operation. The Trimble County Unit 1 Agreement and the Trimble County Unit 2 Agreement provide for the operation and maintenance of both units by LG&E. Trimble County Unit 1 and Unit 2 are adjacent to each other and share resources such as the exhaust stack; coal supply and the transportation thereof; and transmission interconnection. Additional cooling is being provided by a new mechanical draft-cooling tower for Trimble County Unit 1, while Trimble County Unit 2 is using the hyperbolic cooling tower previously used by Trimble County Unit 1. Coal is delivered to the site by barge on the Ohio River. The coal is purchased from a variety of suppliers in Kentucky and Indiana under contracts with varying terms. IMPA anticipates that Trimble County Unit 2 will likely operate on a blend of high sulfur and low sulfur coal. For the low sulfur portion, Trimble County Unit 2 will utilize coal contracted from low sulfur fuel supplies mainly from the Powder River Basin.
Back to top
Prairie State Energy Campus
The Prairie State Energy Campus includes a pulverized coal-fired generating station and associated mine, rail, water, coal combustion waste storage and ancillary support that is located in Washington and Randolph Counties in southwest Illinois. The generating station consists of two supercritical units with a nominal net output capacity of 800 MW each. IMPA’s 12.64% undivided ownership interest in Prairie State is approximately 200 MW. Construction commenced on the Prairie State Project in the fall of 2007 and was completed in 2012.
The Prairie State Energy Campus is situated adjacent to underground coal reserves owned by the Prairie State Participants. The coal mine is expected to supply all the fuel for Prairie State for approximately 30 years. Prairie State is expected to be among the cleanest coal burning plants in the United States. The plant utilizes state-of-the-art control technologies including low NOx burner controls, SCR for NOx removal, dry electrostatic precipitators, wet flue gas desulfurization and wet electrostatic precipitators.
Back to top
Combustion-Turbine Facilities
IMPA has seven wholly-owned combustion turbines and associated facilities aggregating 419 MW. The Combustion Turbines include two 41 MW units, placed in service in 1992 and one 85 MW unit placed in service in 2004 located in Anderson, Indiana; two 41 MW units, placed in service in 1992 located near Richmond, Indiana; and two 85 MW units, acquired by IMPA in 2004, located in Indianapolis, Indiana. IMPA employees operate and maintain the combustion turbines located in Anderson and Richmond. The Georgetown Plant is currently operated and maintained by Indianapolis Power & Light Company.
The Anderson and Richmond Combustion Turbines operate primarily on natural gas, which is delivered under an interruptible transportation contract with Vectren. This contract gives IMPA the option to obtain its own gas supplies with local distribution supplied by Vectren. The Anderson and Richmond Combustion Turbines also maintain an inventory of No. 2 fuel oil as an alternative fuel in the event of interruptions in natural gas supply, or as an economic option. The Georgetown Plant operates solely on natural gas, which is delivered pursuant to a capacity reservation and gas transportation agreement with Citizens Gas. Natural gas used to operate the Combustion Turbines is purchased at market prices.
Back to top
