Duke Energy has requested permission from state regulators to raise rates in June to cover fuel and power costs. This rate hike is separate from another increase Duke Energy has requested for 2027.
The June increase would cover $809 million worth of fuel and power costs incurred by the utility from September 2025 to February 2026. Duke Energy passes the costs of fuel it uses to generate electricity directly to ratepayers — it neither gains nor loses money on these transactions.
The proposed rate hike would raise average rates for Duke Energy Carolinas customers by an additional $6.90 per month, and $7.88 per month for Duke Energy Progress. Here is what is included in the $809 million that Duke is trying to recover.
What is the rate hike paying for?
The single largest expense for both North Carolina utilities was natural gas. Duke Energy Carolinas burned gas and oil to produce nearly 30% of its energy, but those fossil fuels accounted for 47% of its fuel costs, adjusted for fuel sales.
Nuclear power plants provided the most energy of any single resource, but nuclear fuel costs were relatively low.
Duke Energy also purchased power from other grids, including some renewable sources, such as solar and wind. Solar and hydro cost nothing, but generate relatively few units of energy.
The companies also sold an amount of electricity roughly equivalent to 10% of the electricity they purchased from fuels and power.
Duke customers can comment on the proposed rate hike on the North Carolina Utilities Commission website, using the relevant docket number:
- E-2 Sub 1358: For Duke Energy Progress customers, whose average monthly rates would increase by $7.88 on June 1.
- E-7 Sub 1313: For Duke Energy Carolinas customers, whose average monthly rates would increase by $6.90 on June 1.
How do renewables fit into the mix?
When it comes to keeping the lights on, energy resources act a little like a soccer team. Every team member plays their zone. Nuclear and natural gas combustion turbines spend a lot of time on the field, generating the system’s baseload power supply.
Some facilities act a little like a goalie — they’re not spending a lot of time with their feet on the ball, but they can be a real lifesaver when they do. Hydropower is a good example: It provided less than 1% of all the energy generated during the last six months; however, Duke Energy tapped its reservoirs when power demand peaked in the winter.
“During the really cold weather we had gotten in late January and early February, I looked one morning at the height of our demand, and I saw every hydro unit that was available running,” said Bryan Walsh, Duke Energy’s vice president of regulated renewables. The utility operates about 3,400 megawatts of hydropower in the Carolinas.
“Hydro is a great way to turn on a lot of megawatts really quickly, in a very cheap manner,” He said. “But it uses a lot of water, so we tend to deploy it for a couple hours at a time to meet peak demand.”
The same goes for battery storage. The utility charges them during off-peak hours, saving up to two to four hours of energy to expend when demand peaks. It’s a relatively new technology for Duke, but it plans to build out several thousand megawatts of new battery storage by 2034.
Battery storage can be paired with carbon-free power generation, such as solar, to store electricity generated when the sun is out and release that energy to customers at other times, such as at night or on cloudy days.
