Cogeneration Tax Act of 1981

Cogeneration Tax Act of 1981 - Amends the Internal Revenue Code to extend the period for which the energy percentage, for purposes of the investment tax credit, may be applied with respect to cogeneration equipment. Revises the definition of "cogeneration equipment" to include: (1) property comprising a system for the generation of mechanical shaft power; and (2) property which is part of, attached to, directly associated with, functionally related to, or reasonably necessary for the operation of cogeneration equipment. Allows a system using such equipment to be fueled by petroleum coke or petroleum pitch.

Revises the definition of "alternative energy property" to: (1) include equipment at the point of use of an alternate substance which is attached to, directly associated with, functionally related to, or reasonably necessary for the operation of alternative energy property; and (2) allow the use as an alternate substance of petroleum coke or petroleum pitch.

Eliminates the exclusion of public utility property from treatment as energy property.