AEP Ohio and Amazon subsidiary Vadata Inc. have proposed a deal that would cut the cost of electricity at Amazon's three existing data centers in central Ohio. Amazon Web Services uses the centers to provide data storage to Amazon, but also to other companies.

The proposal, which was signed by Vadata and its electricity utility, American Electric Power, would set the stage for the development of as many as a dozen more Amazon data centers in the region, the Columbus Dispatch reports. It is a 10-year deal. The Public Utilities Commission of Ohio would have to approve it.

The public version of the proposal does not detail the value of Amazon's discount, or whether (and how) the discount would change as Amazon developed more data centers. The document blacks out those numbers, citing the need to protect trade secrets.

"Applicant is poised for potential additional development in Ohio,” according to the application. “Each Ohio campus has current capacity to grow fivefold, with each able to support four similar-sized data centers for a combined potential of 15 data centers on the three Ohio campuses” as demand grows for Amazon's services.

Amazon's central Ohio data centers are in Dublin, Hilliard and New Albany, representing an investment of more than $1B by the online retail giant. According to the application, the deal would add more data centers to those communities, not put them elsewhere in central Ohio.

CORRECTION, SEPT. 11, 7 P.M. ET: An earlier version of this story incorrectly stated that the Public Utilities Commission of Ohio proposed the deal.