Duke Energy Corp. utilities have filed a new resource plan with North Carolina regulators, forecasting an "unprecedented" increase in demand over the 2024 update. The company is delaying some renewable additions, such as wind and solar, while boosting gas-fired assets, especially in the near term. The plan also includes the potential addition of a large-scale nuclear reactor.
The 2025 Carolinas Resource Plan updates long-range generation planning by subsidiaries Duke Energy Carolinas LLC and Duke Energy Progress LLC in North and South Carolina. Over the next 15 years, Duke forecasts customer energy demand to grow eight times the rate observed over the previous 15 years.
That growth is more than double what Duke anticipated in its 2023 resource plan.
Since June 2024, the utility has seen another 2,000 MW in new, high-load factor customer additions, Duke Energy North Carolina President Kendal Bowman told Platts in an interview.
Under the proposed plan, Duke expects customer bills to rise about 2.1% annually through 2035.
"We're trying to keep the rates low by squeezing every megawatt out of our existing fleet as we can," Bowman said. "We do see some headwinds and cost increases. We are trying to do things to mitigate that."
The plan reflects recent federal and state policy changes, including expanded supportive measures for large- and small-scale nuclear energy, expiring federal tax credits for renewable projects, and the removal of near-term carbon reduction goals.
Nuclear
Duke's proposal includes a large light-water reactor (LLWR), such as an AP1000, in addition to the small modular reactors (SMRs) featured in previous plans. The company now expects the first SMRs to enter service in 2037, rather than 2035, with possible locations at the Belews Creek gas-fired plant in North Carolina or the W.S. Lee site in South Carolina.
While the 2023 resource plan had called for 600 MW of new nuclear in the form of small modular reactors by 2035, the updated proposal includes 1,117 MW of combined SMR and LLWR capacity by 2037, with "near-term early development activities [to] preserve optionality for both SMR and LLWR."
It also targets 3,350 MW of new nuclear capacity by 2040, including nearly 300 MW of uprates at four existing plants.
Duke's decision to pursue both small- and large-scale nuclear additions was driven by factors such as supportive federal and state policy, regulatory encouragement, demand growth, and the completion of Southern Co.'s Vogtle Nuclear Plant expansion.
"It's all of the above," Bowman said.
Renewables
Duke's new plan eliminates its targets for onshore and offshore wind by 2035, pushing any development beyond 2040. The 2023 plan included 1,200 MW of onshore wind by 2033 and 2,400 MW of offshore wind by 2035.
Wind is "not an economically viable resource for customers through 2040, but will be reassessed at [the] next plan update," the utility said. Duke files resource plans in North Carolina at least every two years.
"Offshore wind resources right now currently face a lot of uncertainty," Bowman said. "We'll re-evaluate wind in the next resource plan."
The integrated resource planning also adjusts solar additions. Instead of 8,200 MW of solar between 2024 and 2031 as proposed last year, Duke now plans for 7,900 MW of solar between 2026 and 2033. By 2040, Duke anticipates adding a total of 15 GW of solar.
Battery storage increased under the 2025 proposal. The plan calls for 6,540 MW of storage by 2035, up from 5,560 MW, and 9,450 MW by 2040. Duke aims to accelerate development to meet near-term growth expectations and leverage tax credits before they expire. Those projects are planned across the Carolinas, including at the company's Allen, Riverbend and Mayo coal plant sites.
The utility is also deferring plans for 1,834 MW of pumped hydro storage by 2034, instead "preserving optionality" for 1,760 MW by 2040.
Duke recently raised its total capital plan to $87 billion. Deferring large capital projects like wind additions and additional customers, such as data centers, will help drive down customer costs, said Bowman and Glen Snider, Duke managing director of integrated resource planning.
Gas, coal
Duke plans to maintain the five combined-cycle gas units outlined in its 2023 modeling while adding two more combustion turbines, for a total of seven. As part of those plans, Duke also added enhanced liquified natural gas storage "to reduce fuel cost volatility and boost reliability."
The combined-cycle units are planned for Person County, North Carolina and Anderson County, South Carolina, with a third site to be determined. Combustion turbines are scheduled for Catawba, Rowan and Richmond counties in North Carolina. A fourth site is still to be determined.
The proposed gas generation is about 2,825 MW of combustion turbines by 2033 and 6,825 MW of combined-cycle units by 2033. This is an increase over the 2023 plan, which included 2,125 MW and 6,800 MW of combustion turbines and combined-cycle units, respectively.
By 2040, Duke targets 4,100 MW of combustion turbines and 8,200 MW of combined-cycle units.
Duke is confident its scale and supplier relationships will shield it from some of the supply chain constraints other utilities face as they look to build out gas-fired fleets, Snider told Platts.
In 2024, clean energy, environmental and customer advocates opposed Duke's plans to add more gas generation to the Carolinas, though some supported the utility's plan after several compromises.
Following federal policy changes, Duke is also evaluating two- to four-year extensions for dual-fuel capability, such as Belews Creek, James E. Rogers Energy Complex (Cliffside) and Marshall.
Flexibility for coal plants could allow Duke to accommodate even greater, or faster, load growth, Snider said.
"We still have a strategy to be out of coal over the coming decade," Snider added. Duke also remains committed to the goal of carbon neutrality by 2050, as required under North Carolina law.
"We spent a decade doing a lot of planning," Snider said. "Now we're in the early phases of executing and we have to continue that execution with appropriate mid-course corrections."
Next steps
The North Carolina Utilities Commission will hold hearings on the resource plan in 2026 — dates are still to be determined — and issue an order by Dec. 31, 2026. Later this year, Duke Energy will also file a resource plan update with the Public Service Commission of South Carolina, incorporating information from the 2025 Carolinas Resource Plan.
