The move will give FirstEnergy an additional $204 million each year. Homeowners using an average of 750 kilowatt-hours of electricity a month will see monthly bills increase by $36 a year.
The money is supposed to go toward improving the utility's electricity distribution grid.
Opponents argue that it opens the door for Akron-based FirstEnergy to put the money toward its struggling nuclear and coal power plants.
FirstEnergy has been trying to convince Ohio lawmakers that it needs $300 million in new charges to save its two aging nuclear plants that are facing stiff competition from natural gas power plants.