Major U.S. utility Duke Energy has made a recommendation that energy storage should grow significantly in response to a carbon reduction plan for its North Carolina and South Carolina operations.
In its "Carolina Carbon Plan" submission to the North Carolina Public Utilities Commission (NCUC), the company said it hopes to deploy 3,700MW to 5,900MW of energy storage systems in its service area by 2035.
The first battery energy storage system (BESS) project deployed by Duke Energy is a 9MW battery energy storage system in Asheville, North Carolina, which will be commissioned in 2020.
The company said this would support growth in installed renewable energy capacity, including tripling the installed capacity of solar power facilities from current levels and adding wind power resources to diversify its renewable energy portfolio.
This equates to around 7.6 GW to 11.9 GW of new solar power capacity by 2035. In addition, by the end of 2022, the company will have 5GW of solar power grid-connected in its Carolina service area, in addition to 1.9GW of solar power facilities planned or under development.
In addition to these developments, Duke Energy also wants to be allowed to take what it describes as "initial steps" to develop an on-demand clean or carbon-free Zero Emissions Load Tracking Resource (ZELFR). This could include advanced nuclear power plants, carbon capture, storage and utilization technologies and other technologies such as next-generation geothermal or hydrogen energy storage.
The company said these ZELFR projects and wind facilities are relatively new in the Carolinas' energy mix and will begin to emerge by 2030.
An executive order issued by North Carolina in January set a policy goal of reducing carbon emissions by 50 percent from 2005 levels by 2030, and plans to achieve net-zero emissions by 2050.
Duke Energy claims its Carolina carbon plan meets those goals, and all options in its proposal would meet other metrics set by the executive order, including selecting the lowest-cost option and maintaining power system and supply reliability.
The company said it is taking all of the above approaches and using its proposed mix of technologies, including natural gas, small modular nuclear reactors, solar power facilities, wind power and energy storage systems.
The company will also take immediate action to implement energy efficiency and demand-side management, and to upgrade the grid so that it can accommodate a higher share of renewable energy.
Once implemented, the plan will be reviewed every two years.
The company claims the plan could cut carbon dioxide emissions by 70 percent by 2030 and become carbon neutral by 2050, while it also pledged to close its coal-fired power plants in North and South Carolina by 2035.
Duke Energy said the company's transmission system between South Carolina and North Carolina helps keep costs low and maintain reliability, citing customers paying less than the national average for electricity. The plan, which will also be submitted to the South Carolina Public Service Commission, requires that electricity bills paid by customers must increase by 1.9% to 2.7% annually between now and 2035.
Duke Energy's plan includes four separate portfolio options, each with a slightly different mix of resources. While one of the scenarios could achieve a 70% CO2 reduction by 2030, others would take longer (until 2032 or 2034) to achieve this goal, but all four would be achieved by 2050 Carbon neutral.
Duke Energy has approximately 7.4 million energy service customers in six states and approximately 1.5 million natural gas service customers in four states. In March this year, the company announced the opening and operation of three lithium-ion battery energy storage projects in Florida, with a total scale of 34MW/58MWh. A few weeks ago, Duke Energy partnered with Honeywell to launch microgrid partnerships across the United States.
The company's planning process came under criticism in 2021, when energy consultancy E3 described its 2020 Integrated Resource Plan (IRP) as having some flaws. E3 pointed out that the Integrated Resource Plan (IRP) did not effectively allow the diversity benefits of solar power generation and storage systems to be realized.
Duke Energy's plan considers the roles of solar and energy storage systems separately at different steps in its process, which E3 believes means the synergies that exist between the two are being ignored.
