The company provides energy to over 2m houses in Carolina and also supplies power to businesses in central and western North Carolina, Triad and Charlotte.

Duke Energy North Carolina president David Fountain said: "Through smart investments in cleaner energy plants and renewable resources, safely managing coal ash, and the grid that powers our lives and improves reliability, we are focused every day on providing customers increasing value and laying the foundation for a smarter energy future."

Duke Energy Progress, which serves electric customers in parts of central and eastern North Carolina and in the Asheville region, filed a similar request to adjust rates June 1. Duke Energy Progress customers will not be affected by this new request.

Based on these investments, the filing with the North Carolina Utilities Commission (NCUC) requests to increase revenues by about $647 million, for an overall average rate increase across all customer groups of 13.6 percent. Since Duke Energy Carolinas' last request to adjust rates in North Carolina in 2012, this represents approximately a 2.5 percent annual increase.

The specific increase for individual customer groups would vary, depending on the rate they pay. The average rate increase from the proposed changes for residential customers would be 16.7 percent, while commercial and industrial customers would see an average increase of 10.9 percent.

If the proposal is approved by state regulators, a residential customer who uses 1,000 kilowatt-hours (kWh) of electricity monthly would pay about $122.68 per month, reflecting an increase of $18.72 per month. Duke Energy Carolinas has included in its request options to spread recovery of certain costs over multiple years to reduce the immediate impact on customer bills.

Duke Energy Carolinas has maintained rates below the national average, and with the proposed change, customers would continue to pay rates lower than in 1991, when adjusted for inflation.

"As our state grows, and as we think about the future energy infrastructure required to serve our customers, a smarter grid will facilitate cleaner energy sources and provide customers the tools they need to make more informed energy decisions. We are committed to smart investments that balance the energy needs of our customers with competitive rates.", Fountain added.

Generating cleaner energy

Duke Energy Carolinas has retired half of its older, less-efficient coal plants that do not have state-of-the-art emission controls and replaced them with cleaner, natural gas-fueled plants. The utility also supports the sustainable growth of solar energy, helping move North Carolina to second in the nation for overall solar power.

Nuclear energy is also a vital component of Duke Energy's generation portfolio now and in the future – providing reliable, carbon-free electricity to the Carolinas. However, Duke Energy is seeking NCUC approval to cancel the development of the Lee Nuclear project due to the recent bankruptcy of Westinghouse Electric Company, a subsidiary of Toshiba Corporation, and other market activity. Most notably, risks and uncertainties to initiating construction on the Lee Nuclear project have become too great and cancellation of the project is the best option for customers. Duke Energy will maintain the license to build new nuclear at this site in the future if it is in the best interest of customers.

Investments include:

Highly efficient natural gas power plant (Anderson County, S.C.) that continues to reduce carbon emissions

Two new solar sites (Monroe and Mocksville, N.C.) that provide 75 megawatts of emissions-free energy to Carolinas homes and businesses

Nuclear licensing and initial development costs at the Lee Nuclear site

Managing coal ash responsibly and recycling byproducts

Duke Energy Carolinas is responsibly managing coal ash and safely closing ash basins at its coal sites in the Carolinas. Duke Energy recycles about 75 percent of coal combustion byproducts, such as gypsum and coal ash, being produced at its plants in North Carolina, and is recycling or has plans to reuse material at all of its plant sites in the state. Customers will never be asked to pay for costs associated with the company's response to the Dan River coal ash release from a Duke Energy Carolinas ash basin in 2014, or for any fines or penalties the utility has incurred from the Dan River release.

Investments include:

Costs since 2015 for compliance with new federal and state regulations and safe closure of ash basins at seven sites in the Carolinas

Beneficially using nearly 3 million tons of coal ash from the Riverbend Steam Station

Enhancing reliability and customer experience

Duke Energy Carolinas invests in the latest innovations to make electricity more reliable and give customers more control of their energy use to manage their bills.

Investments include:

Storm hardening and self-optimizing grid technology that will help reduce outages and improve reliability for customers and allow the utility to remotely manage the grid

Smart meters to enable more energy-saving, bill-lowering tools for customers and faster service connection and outage detection. Additionally, customers can pick their own due date and receive energy usage alerts.

Public process

Duke Energy Carolinas will demonstrate to the NCUC why the proposed increase is appropriate through a public review process that includes numerous opportunities for public comment. There will also be an evidentiary hearing in Raleigh, at which the commission will consider written and oral testimony. Duke Energy Carolinas has requested that new rates, as approved by the NCUC, go into effect spring 2018.