Construction work on the plant, which is the company's second such development in the UK, will begin at the start of next year.
Dave Rogers, regional director for climate and renewables at E.ON, said the company was "delighted" to receive the green light for the project.
He explained: "Biomass power stations offer us an exciting opportunity to help combat climate change by using carbon neutral' products in the place of traditional fossil fuels to generate electricity - further proof of our commitment to changing energy in the UK."
Details about the development have come after E.ON withdrew from a scheme to create a windfarm near Ferndale in Wales.
Research into the proposed renewable energy site found that the project could create noise pollution for residents living nearby.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.