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 (NO_X) removal facilities.  Installation of a Selective Catalytic Reduction (SCR) system for NO_Xcontrol was completed in 2004, and in 2008, Gibson Unit 5 upgraded its flue gas desulfurization system to increase SO₂ removal efficiency.

IMPA has a 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.