Ohio Rev. Code § 4909.152: Consideration of efficiency, sufficiency, adequacy of facilities.

In fixing the just, reasonable, and compensatory rates, joint rates, tolls, classifications, charges, or rentals to be observed and charged for service by any public utility, the public utilities commission may consider the efficiency, sufficiency, and adequacy of the facilities provided and the services rendered by the public utility, the value of such service to the public, and the ability of the public utility to improve such service and facility.

If the commission determines that the facility or service is inefficient, insufficient, or inadequate, the commission may order the public utility to improve such facility or service to a level determined by the commission to be efficient, sufficient, or adequate. However, in any order entered pursuant to section 4909.19 of the Revised Code, the commission shall authorize a rate of return that is just and reasonable.