The Duke Energy Pee Dee rate increase appeal puts a question in front of South Carolina's highest court that most utility customers never see argued: not whether rates can rise, but how soon a new law lets them. Duke Energy Progress has asked the South Carolina Supreme Court to overturn the Public Service Commission's July 15, 2026 decision denying a 4% increase for its Pee Dee customers, according to the SC Daily Gazette. The utility filed the appeal in late July. The state's Department of Consumer Affairs has asked the court to dismiss it, arguing the matter belongs with the Commission. For a business in Florence or Darlington counties the court will decide the timing of the next increase. It will not decide the size of the bill, and that is the part worth acting on.
What Duke Energy asked for, and what regulators said
The request has a short history. In March 2026 Duke Energy Progress became the first utility in South Carolina to apply under the state's new rate stabilization program, a mechanism the Legislature approved as part of the energy package signed in May 2025. The program had been available only to gas utilities; the 2025 law extended it to electric providers and allows a utility to seek annual rate adjustments for up to five years. Customers can still protest each adjustment, regulators keep the final approval, and the process does not reopen the utility's allowed return, which stands at 9.99% for Duke Energy Progress, according to the Gazette.
Duke asked for 4%, reduced from an initial 6.6%, to take effect in August 2026. On a typical residential bill of 1,000 kWh, which was running about $156 a month, the request followed a previous increase of about $11.23 a month by only 41 days. On July 15 the Public Service Commission denied it, ruling that the utility could not raise rates for a year after first applying under the program.
Duke's statement on the appeal is direct: "The PSC's decision effectively sidelines the Legislature's clear direction to allow more timely cost recovery of prudent utility investments and more predictable customer rate adjustments by refusing to apply the framework as written." The Supreme Court will decide whether the Commission read the law correctly, and when the first adjustment can take effect.
What the case means for a business in the Pee Dee
Two things are settled regardless of the ruling. The first is direction: the utility has a legal path to annual adjustments for up to five years, and it has already used it once. The second is scope: percentage increases under the program apply across customer classes, so a plant, a warehouse or a farm sees the same percentage on its demand and energy charges that a household sees on its total.
What the court decides is timing, and timing matters less to a commercial account than it sounds. A facility's bill is driven by the demand charge on its highest measured interval, by the energy charge on every kilowatt-hour and, on some schedules, by a power factor penalty. Every one of those scales with the tariff. Whether the next adjustment lands in August 2026 or a year later, the way a business keeps its own bill from tracking the tariff is the same: use less from the meter at the moments that cost the most, and generate part of what it uses.
There is also a constructive reading of the program itself. Annual adjustments are more predictable than a large rate case every few years, and predictability is something a facility can plan against. A business that knows the direction of its utility costs for five years has a clearer basis for a fifteen-year decision about its own roof than one facing a single unknown filing.
What a South Carolina facility can decide now
We build across the state, and our page on commercial solar installation in South Carolina sets out the utilities, the interconnection procedures and the incentives that apply here. The sequence on a Pee Dee site is the same as anywhere else.
Start with twelve months of Duke Energy Progress bills. The demand charge line, added up for a year, is the ceiling on what a battery can save. The energy charge, added up the same way, is what solar addresses. If there is a power factor penalty, it is usually the cheapest of the three to remove, which is why we check for it first through power factor correction services before we quote anything larger.
Solar fixes the cost of daytime energy on the day the system is commissioned, which is exactly the property a rising tariff cannot offer. The demand charge is a separate problem, because the utility can set a facility's billed peak on a cloudy afternoon or after dark; that is the job of commercial battery storage, sized from interval data so the meter never records the peak. Whether a battery earns its keep on your rate schedule is a question our article on commercial battery storage payback shows you how to answer from your own bill.
On the incentive side, both solar and paired storage have been eligible for the 30% federal solar tax credit under current rules, subject to construction and placed-in-service deadlines that your accountant should confirm. We prepare the documentation; the credit is claimed on your return.
What happens next
The Supreme Court will rule on whether the Commission applied the rate stabilization law as written, and the Commission will then take up the adjustment on whatever schedule the ruling sets. A facility that starts its own assessment now will have a design, an installed cost and a payback range in hand before either of those things happens.
Run the commercial solar savings calculator with an average monthly bill to see the order of magnitude, or send twelve months of bills through our proposal request form. We will tell you which part of the coming adjustments your facility can do something about, and, if the numbers on your schedule do not work, we will say that too.