It’s part of a newly-filed update to Duke’s 2022 integrated resource plan as the utility aims to comply with North Carolina’s emission mandates. That 2021 law requires utilities to reduce carbon dioxide emissions by 70% by 2030, compared with 2005 levels. The law also calls for net-zero emissions by 2050.

In the updated filings, Duke offered three scenarios that would get the company to 70% by 2030, 2033 or 2035.

The utility prefers the 2035 timeline. By that year Duke is proposing to add 600 MW of capacity from two small modular reactor sites, with both sites being the same reactor technology.

“Advanced nuclear will provide significant operational flexibility that will be needed to support increased deployment of renewable energy resources,” said the utility in its latest filings.

In a timeline prepared in filings to regulators, the utility said it plans to choose an SMR technology for the Belews Creek site between 2023 and 2025. Duke plans to apply for an early site permit from the U.S. Nuclear Regulatory Commission (NRC) in mid-2025.

The projected in-service date for the Belews Creek SMR would be the first quarter of 2034, with the SMR at the second site coming online in the first quarter of 2035.

Duke plans to end coal-fired power generation at Belews Creek by 2036. The 2,200 MW, two-unit coal and natural gas plant is located on Belews Lake in Stokes County, North Carolina. In 2020 and 2021, natural gas was added to the station to allow up to 50% natural gas co-firing on both units.

Duke’s recommended 2035 portfolio also includes a “near-term action plan” that would build up additional solar and wind generation and provide more electricity storage in batteries by the early 2030s.

While Belews Creek would be retrofitted for new nuclear, Duke’s Roxboro and Marshall coal-fired plants would shift to natural gas. Duke says those combustion turbine plants would be able to blend hydrogen for electricity.

Duke Energy said it is also in the process of seeking 20-year license extensions for the 11 existing nuclear units operating at six plants in the Carolinas.

Duke Energy expects the deal involving the unregulated business to close by the end of 2023. The investor-owned utility expects net proceeds of approximately $1.1 billion from the transaction.

Duke began shopping its renewables business in Sept. 2022 as it sought to focus on the growth of its regulated businesses.

“As one of the country’s largest renewable energy operators, Brookfield has the resources to support the continued growth and success of the Commercial Renewables’ portfolio,” Duke Energy CEO Lynn Good said in a statement. “This sale is an important step in our transition into a purely regulated company with significant grid and clean energy investment plans that will deliver benefits to our customers and stakeholders.”

The sale agreement includes more than 3,400 MWac of utility-scale solar, wind, and battery storage across the U.S., net of joint venture partners ownership, in addition to operations, new project development, and current projects under construction.

The primary operations of Duke’s utility-scale renewables business will remain in Charlotte, N.C. and the Duke Energy employees that support the business will transition over to Brookfield to maintain business continuity for its operations and customers, the companies said.

The agreement between Duke and Brookfield is subject to regulator approval by the Federal Energy Regulatory Commission.

Duke said it is still moving forward with a separate sale for its distributed energy business, which the utility also intends to close by the end of the year.

A microgrid has been placed into service in the town of Hot Springs, North Carolina that will be able to power the entire town during an outage.

The Hot Springs microgrid consists of a 2 MW (AC) solar facility and a 4.4 MW/4.4 MWh lithium-based battery storage facility. While the battery only technically has a 1-hour duration, the town's typical load is typically less than 1 MW, potentially extending the battery's available duration to at least four hours.

In addition to providing clean and reliable energy for the town of Hot Springs, the microgrid will also perform grid services, such as frequency and voltage regulation, as well as ramping support and capacity during peaks on Duke Energy's system.

“Duke Energy has numerous smaller microgrids on our system, but this is our first microgrid that can power an entire small town if its main power line experiences an outage,” said Jason Handley, general manager of Duke Energy's Distributed Energy Group.

Hot Springs has a population of just over 500. The town has limited rerouting options in the event of an outage.

During its testing phase, Duke Energy’s microgrid was able to pick up the town’s entire load from a black start without any help from the energy grid – using only solar and battery storage to restore power. The microgrid served the town’s load while the company gathered data.

Duke Energy worked with the technology company Wärtsilä, which supplied the battery energy storage system for the project. The microgrid utilizes Wärtsilä’s energy management system, the GEMS Digital Energy Platform, for integrated control of both the solar and energy storage facilities.

Duke Energy has over 60 MW of microgrid capacity connected throughout its regulated areas.

In Asheville, North Carolina, Duke Energy operates a 9 MW lithium-ion battery system at a substation site in the Rock Hill community.

In Haywood County, North Carolina the company has a 3.8- kWh lithium iron phosphate battery and 10 kW solar DC microgrid installation serving a communications tower on Mount Sterling in the Smoky Mountains National Park. 

Duke Energy said it has completed a 700 MW solar project portfolio in Florida as part of its resource plan filed with regulators.

Completion of the 74.9 MW Charlie Creek Solar Power Plant in Hardee County marks the last of 10 solar projects in Duke's commitment with the Florida Public Service Commission to bring 700 MW of solar generation online from 2018 through 2022.

Melissa Seixas, Duke Energy Florida state president, said the utility plans to provide 1,500 MW of solar generation to residents and businesses by 2024, representing a $2 billion investment.

Duke set goals of net-zero methane emissions from its natural gas business and at least a 50% carbon reduction from electric power generation by 2030. The utility has a net-zero target of 2050.

Duke Energy recently completed the first of 10 community solar projects in Florida as part of a new program. Once completed, the Clean Energy Connection community solar program will feature 750 MW of generating capacity.

The Fort Green project was built on around 500 acres of former mining land. The project consists of nearly 265,000 solar panels, using a fixed-tilt racking system that will produce enough energy to power more than 23,000 average-sized homes at peak production.

In August, Duke Energy announced that two battery storage projects in Florida totaling 17.2 MWh of combined energy capacity were brought online in Alachua and Hamilton counties.

NOTE: Be sure to watch our POWERGEN+ network webinar: “How the fast-ramping SGT6-9000HL at Duke Energy’s Lincoln Station supports solar and the path to net-zero.”

Duke Energy’s Lincoln Combustion Turbine Station is now certified with the Guinness World Records title for the “most powerful simple-cycle gas power plant.”

The plant, powered by a Siemens Energy SGT6-9000HL turbine, achieved an output of 410.9 MW during testing on Jan. 30.

Siemens Energy is currently testing the 60Hz SGT6-9000HL turbine at the Lincoln site, located near Denver, North Carolina. In April 2020, the company synched the unit to the grid for the first time.

Siemens Energy plans to turn the unit over to Duke Energy in 2024. It would become the most efficient simple-cycle combustion turbine in the utility’s fleet and 34% more efficient than the other turbines at the Lincoln site.

The SGT6-9000HL is based on four generations of technologies and five previous models, starting with the SGT-2000E in the 1980s. It is designed to run longer between maintenance cycles.

The HL-class’s engine architecture is composed of an air-cooled four-stage power turbine, hydraulic clearance optimization for higher efficiency at full load while facilitating immediate restart, a steel rotor design with Hirth serrations and a central single tie rod and a “can annular” combustion system, according to Siemens Energy.

The advanced can-annular combustion system with dual fuel capability allows for higher firing temperatures and more operational flexibility. Twenty-five premix burners improve the fuel/oxygen mixing, and the ACE combustion system allows for GT turn-down to 30 percent GT load.

The turbine has fast-responding capabilities, with a ramp up and down rate of about 85 MW per minute. This is an important quality when integrating with renewables.

Duke Energy started construction on its Lincoln expansion project in September 2018. The 16-unit power plant was selected because its 746-acre site allowed room for expansion.

Duke Energy announced the completion of two battery storage projects in Florida totaling 17.2 MWh of combined energy capacity.

The recently completed Micanopy battery site in Alachua County is 8.25 MW/11.7 MWh and is located 15 miles southwest of Gainesville. The site provides a cost-effective solution for focused power quality and reliability for the town of Micanopy and nearby neighbors.

The Jennings battery site, completed in April, is 5.5 MW/5.5 MWh and is located 1.5 miles south of the Florida-Georgia border in the town of Jennings in Hamilton County. This site will continue to improve power reliability through energy storage as an alternative solution to installing new and more costly distribution equipment.

Earlier this year, Duke Energy Florida announced the completion of three battery projects in Gilchrist, Gulf and Highlands counties. The new sites are part of Duke Energy’s commitment to have six battery sites, totaling 50 MW, in operation in Florida this year.

Duke Energy Florida is also developing a 3.5 MW solar plus storage microgrid site at Pinellas County's John Hopkins Middle School. The microgrid will support grid operations and provide backup electric power to the school when it must operate as a special needs hurricane evacuation shelter.

The microgrid consists of a 1 MW solar parking canopy array, a 2.5 MW battery and associated controls, which will store and deploy clean, renewable energy to the school and grid. The project enhances electric service and grid operations for customers.

The groups, in filing a formal response to the proposed electricity-production shifts the utility offered in May to the state Utilities Commission, also make an alternate proposal to reduce carbon dioxide emissions by 70% by 2030 as compared to 2005 levels. They say it would require more solar and wind power and battery storage use than Duke’s plan.

The coalition says its plan would do better with energy savings through efficiency initiatives than what Duke proposes to comply with the landmark 2021 state law that mandates the 70% reduction as well as zero-net CO2 emissions by 2050.

According to a report filed with the commission July 20 prepared by an outside firm hired by the coalition, the mandates can also be met at a lower cost for customers, who are expected to pay higher bills for these shifts.

“Duke’s carbon plan is deeply flawed,” said Luis Martinez, director of Southeast energy at the Natural Resources Defense Council, one of the groups that filed written comments by a deadline July 15. “But this modeling shows that a less costly plan, which also significantly reduces emissions, is possible for North Carolina.”

The law directs the Utilities Commission to tell Charlotte-based Duke Energy how to meet these reductions by the end of the year, and says the seven-member panel can examine “the latest technological breakthroughs to achieve the least cost path,” among other considerations. The commission is holding in-person hearings this month and online meetings next month to take public comment.

Duke spokesperson Bill Norton said July 21 that the utility’s priority remains “to produce the most efficient, reliable, least-cost way to deliver the clean energy our customers deserve and expect” and that Duke looks forward to reviewing proposals and “providing constructive feedback” to the commission.

The coalition, which also includes the North Carolina Sustainable Energy Association, Southern Alliance for Clean Energy and the Sierra Club, is also critical of Duke Energy’s plan because it wants four energy-portfolio alterations it proposed approved, not just one. The utility says that would provide more flexibility and time to evaluate emerging electricity sources.

All four portfolios do envision retiring Duke Energy’s remaining coal-fired power plants in North Carolina by 2035. They also would rely on hydroelectric power storage; an emerging form of small nuclear power plants; and additional natural gas-powered plants, which can provide energy on cloudy or high-demand days.

Natural gas burns cleaner than coal and is considered a bridge fuel while other alternate energy sources are ramped up. But critics say the methane contained in natural gas and that can leak is disproportionately more damaging to the climate than carbon dioxide.

Three of the four portfolios don’t reach the 70% reduction target by 2032 or 2034, but the utility said those plans would result in slightly lower average annual increases on retail power bills through 2035.

The law gives the commission the ability to delay the 2030 target by up to two years, and even longer if regulatory and construction delays for nuclear or wind energy facilities arise, or if the electric grid’s performance is questioned.

Still, “the commission has an obligation to develop a plan to achieve the required carbon reduction requirements set forth in law,” the coalition’s written comments say, calling Duke’s proposal a “Choose-Your-Own Adventure Carbon Plan.”

The utility’s plan covers activities in North Carolina and South Carolina, but the 70% reduction only applies to North Carolina. Duke Energy Carolinas and Duke Energy Progress serve 4.4 million customers in the two states. The coalition said its proposal could trim anticipated higher costs for ratepayers by 2% to 7% through 2030 compared to Duke’s plan.

A 16 MW combined heat and power (CHP) plant is now operating on the southern edge of Purdue University’s West Lafayette, Indiana campus.

The gas-powered plant was built and is owned and operated by Duke Energy. It produces electricity for the company’s Indiana customers and provides thermal energy in the form of steam for Purdue’s heating and hot water needs.

Through an approved agreement, Duke Energy will sell to Purdue the steam the plant produces. The plant can produce up to 150,000 pounds of steam per hour, according to the utility. 

By using steam from the new CHP plant, the university will have more operational flexibility. In the event of an electric grid disruption, the new plant could provide emergency power to help keep the campus running.

In combined heat and power, or cogeneration plants, heat that would otherwise be wasted in the production of electricity is captured and used. Because of this, CHP plants require less fuel to produce the same amount of total energy, resulting in reduced environmental emissions.

According to Duke Energy, the new plant is projected to reduce carbon dioxide emissions by approximately 50,000 metric tons.

In 2019, Purdue trustees approved leasing one acre of land to the utility, which allowed for the building of the CHP plant.

Duke Energy has pursued similar CHP plant partnerships with universities and other institutions.

The utility also has a CHP plant at Clemson University in South Carolina. Duke Energy and Clemson, along with Siemens Energy, teamed up to study the use of hydrogen for energy storage and as a low-carbon fuel source at the Clemson CHP plant. The U.S. Department of Energy (DOE) awarded a $200,000 grant for the pilot research initiative.    

The pilot, called H2-Orange – a nod to hydrogen gas and the collaboration with Clemson University – began in March 2021 and would include studies on hydrogen production, storage and co-firing with natural gas.