US utilities, Duke Energy Carolinas and Duke Energy Progress have filed their Integrated Resource Plan (IRP) with the Public Service Commission of South Carolina (PSCSC) aiming to ensure energy reliability for its customers. Mike Callahan, Duke Energy’s South Carolina state president explained that over the next 15 years, electricity demand in the Carolinas is projected to surge by around 35,000 GWh, which is more than the annual electricity generation of Delaware, Maine and New Hampshire combined. “We’re preparing for this extraordinary growth in energy demand by prioritising grid reliability, energy affordability and the deployment of a diverse range of energy options that support the sustainability goals of our South Carolina customers,” he said.
The IRP includes three energy portfolios that provide a range of generation options, reflecting the companies’ approach to powering the growing energy needs. It recommends Portfolio 3 as the most prudent path forward to comply with South Carolina and other applicable law. The plan says this provides for a reliable, affordable and smart clean energy transition that supports the Palmetto State’s economic prosperity. The company also recommends a near-term action plan based on this portfolio.
“This disciplined plan presents a path to build upon the tremendous economic development activity in our state that will contribute to the long-term vibrancy and prosperity of South Carolina, while leveraging tax incentives and credits and operational efficiencies to help keep costs for the state’s energy future lower than they would otherwise be,” Callahan noted.
Portfolio 3 takes into account the dramatic recent growth in the Carolinas and the accelerating transition to electric transportation by residential and non-residential customers alike while supporting plans to phase out coal by 2035, protecting customers from the effects of the coal industry’s decline.
The plan envisages extending the lives of Duke Energy’s six NPPs and extending the licence of the Bad Creek pumped hydro storage facility in Oconee County and doubling its peak hourly capacity. Duke Energy says expanding operations at Bad Creek will provide economic benefits of $7.3bn to South Carolina by 2033 as a result of construction and general infrastructure activity.
Portfolio 3 takes an “all of the above” approach with a diverse and reliable set of solutions, including new hydrogen-capable natural gas resources, energy storage, small modular nuclear reactors complemented by fuel-free renewable energy. It seeks to reduce the challenges of growth and the transition from coal toward a lower carbon future by expanding energy efficiency and demand response options.
The IRP represent an evolution of earlier plans filed with the PSCSC and shared with stakeholders. The information gathered throughout stakeholder consultation was factored into these plans.
“We appreciate the significant input we received from everyone that helped inform these plans,” Callahan said. “Preparing for a successful energy future for South Carolina will take coordination and cooperation among many varied interests, and we look forward to continuing this dialogue on issues that are critically important to our state’s continued economic prosperity.”
Filing the IRP with the PSCSC initiates a public regulatory process at that involves the evaluation of thousands of pages of testimony and data from the company, other parties and customers. A hearing will be scheduled where this information is thoroughly evaluated and ultimately the PSCSC will order a path forward, most probably in mid-2024.
The IRP will also be submitted to the North Carolina Utilities Commission (NCUC), where a similar but separate regulatory process will take place. These plans are checked and adjusted every two to three years with updates filed in both states.
Duke Energy serves about 830,000 households and businesses in South Carolina through Duke Energy Carolinas and Duke Energy Progress. The company employs 27,600 people. Duke Energy operates 11 nuclear units at six sites in the Carolinas. The combined generating capacity of these facilities is nearly 11,000 MWe. The nuclear fleet generates approximately half of the electricity provided to its customers in the Carolinas, with production costs among the lowest in the USA.
The NPPs include:
- Brunswick NPP, a two-unit plant with a capacity of 1,870 MWe in Southport, North Carolina (NC), which began operation in 1975;
- Harris NPP, a single unit 964 MWe plant in New Hill, NC, which began operation in 1987;
- Oconee NPP, a 2,554 MWe three-unit plant in Seneca, South Caroline (SC), which began operation in 1973;
- Catawba NPP, a two-unit plant with a capacity of 2,310 MWe in York, SC that began operation in 1985;
- McGuire NPP, a 2,316 MWe two-unit plant in Huntersville, NC, which began operation in 1981; and
- Robinson NPP, a single unit 759 MWe plant in Hartsville, SC that began operation in 1971.
Brunswick, Harris, McGuire and Oconee also feature energy education centres. Extending the operating lives of these six plants is a "bedrock assumption" in all three portfolios, the IRP says. The current operating licences begin to expire in the 2030s, and the regulatory process for each 20-year subsequent licence renewal could take up to four years. Duke Energy submitted its first application, for NPP, in 2021, and the aim is to submit an application for a nuclear station every three years, with these tentatively planned for 2024, 2027, 2030, 2033 and 2036.
Oconee, McGuire and Catawba are also being considered for power uprates. At Oconee, measurement uncertainty recapture resulted in an additional 15 MWe per unit during 2022-2023 and this is included in the IRP. The Harris, Robinson and Brunswick plants have already undergone extensive uprates but uprates to McGuire and Catawba will need extensive component replacement and further investigation is required into the cost and timing of the possible projects.
