CHARLOTTE, N.C. (AP) — Duke Energy Progress formally asked North Carolina utilities regulators on Thursday to let it raise electric customer rates starting next year, with revenues generated used in part to toughen the electric grid and make it more flexible for renewable power.

The general rate increase request, if approved by the state Utilities Commission, would begin in October 2023. Smaller additional rate increases also are proposed for October 2024 and October 2025.

Under the proposal, Duke Energy Progress would seek a cumulative rate increase of 16%, with an 18.7% increase for residential customers, the company said.

Duke Energy Progress is one of Charlotte-based Duke Energy’s two electric subsidiaries in the state. It serves 1.5 million customers in eastern and central North Carolina — including those in Raleigh, Fayetteville and Wilmington — as well as in and near Asheville.

A typical Duke Energy Progress residential customer would see their monthly bill rise from $126.43 per month to $141.15 in late 2023, with smaller increases in 2024 and 2025 to $151.98, according to a news release.

Retail sales net revenues would grow by $615 million through the proposal. Seventy-five percent of spending over the next three years consists of grid infrastructure improvements, according to the utility. Regulated utilities are permitted to earn a return on their business activity. The commission’s Public Staff and customers can challenge the proposal.

Both Duke Energy Progress and Duke Energy Carolinas – which serves a swath of customers that includes those in Charlotte, the Triad and Durham, filed rate cases in 2019. The commission approved partial increases in 2021, with settlements to address costs to clean up coal ash pits.

Duke Energy Carolinas likely will propose its own new rate case in early 2023, spokesperson Bill Norton said.

Duke Energy Progress said the proposal would create a new program for low-income customers that could reduce their bills by $42 per month. And new energy efficiency programs offered to all customers can help generate savings that “significantly offset” rate increases, the release said.

The Utilities Commission is currently weighing how it will permit the two subsidiaries to retool electric-generating capacity to comply with a law that demands carbon dioxide emission reductions by 2030 and 2050. Any approved plan will result in rate increases over time, too.