On Oct. 26, the S.C. Public Service Commission will open a two-day workshop in Columbia on a question that has not yet shown up on most Charleston-area power bills but could: when a data center needs as much electricity as a small city, who pays for the power plants and lines built to serve it?
The answer matters to businesses served by Dominion Energy South Carolina, whose territory includes the Charleston metro area, and by state-owned Santee Cooper and the cooperatives it supplies. If a utility builds for a big customer that shrinks, leaves or never arrives, everyone else can end up paying.
So far the region has seen more data center talk than load. In an Aug. 14 filing, Dominion said it has one large data center operating in its territory and one more prospective large customer “reviewing more detailed contractual commitments.” It also said its capacity is constrained and that “in several instances” it has told prospects it does not currently have the capacity they asked for.
What the workshop is
Duke Energy asked the commission in May to open the docket; Dominion joined under its rate case settlement. It covers new loads of 50 megawatts or more. Parties will present their views and commissioners can ask questions, but there will be no cross-examination, under the commission’s scheduling order. The workshop is not a rate hearing: the docket was opened to collect comments, and the commission can decide later whether further proceedings are needed. More than a dozen parties are taking part, including Google, Nucor Steel, the S.C. Department of Consumer Affairs, the S.C. Small Business Chamber of Commerce and a coalition that includes the Charleston-based Coastal Conservation League.
What Dominion says it already does
Dominion has no separate rate class for large, high-load-factor customers such as data centers. They generally take service under its large general service tariff, with contract terms layered on top, including minimum bills, credit requirements and an early exit fee, the utility told the commission.
“Long-term investments require long-term commitments,” the company wrote.
On Oct. 15, Dominion added that its one current large data center customer “has contractually agreed to cover all costs to serve its load so other customer classes do not do so.” It did not name the customer.
The utility also argued that big customers “can spread the utility’s fixed costs over more units of consumption and, for that reason, may help lower average system costs borne by all customers over the long term.” It acknowledged “unprecedented load growth” and said changes to rate design and contract terms “may be warranted.”
The other side
Most of the other parties that filed comments want public tariffs instead of private contracts.
The Sierra Club said “neither utility provided any analysis to support its assertions” that current practices protect other customers. The Coastal Conservation League and its partners asked the commission to order utilities, once this docket ends, to propose large-load tariffs within six months and to file their large-load forecasts publicly twice a year.
“There is simply no way to ensure that current practices are adequately protecting customers from the risks associated with new large loads without a transparent, mandatory process to review the tariffs applicable to these customers,” the groups wrote.
The Department of Consumer Affairs said that chief among the commission’s considerations “should be that new large loads pay for all costs associated with their addition to the electric system.”
Google, which is building a data center in Dorchester County that Dominion will serve, according to The Post and Courier, took a middle position. “Google believes that data centers must pay their fair share of new infrastructure that is built to serve their demand,” it wrote, adding: “Data centers are not the sole driver of new infrastructure investments, nor are they the sole beneficiary.”
Nucor, whose Darlington mill is served by Duke Energy Progress and whose Berkeley County mill buys power from Santee Cooper, asked that any new large-load rules exempt existing customers such as long-established manufacturers.
Santee Cooper’s tougher rule
Santee Cooper already has the kind of tariff the critics want. Since April 2025, an experimental rate has been mandatory for data centers using more than 50 megawatts and for cryptocurrency mining and other portable computing loads above 1 megawatt.
A customer must sign up for at least 15 years and pay in full for its connection and any network upgrades before Santee Cooper builds anything to serve it. It must also post collateral equal to 15 years of minimum bills, at least a year of it in cash. S.C. Appleseed Legal Justice Center, which represents low-income families in the docket, called the rate, with a few exceptions, “a reasonable floor” for the protections the commission should require of other utilities.
Santee Cooper now proposes to replace the experimental rate, which expires no later than April 2029, with a standing “high impact load” schedule and to lower the threshold to 20 megawatts, according to proposed rate schedules on its website. Its board is scheduled to vote Oct. 30.
What the forecasts show
Dominion’s 2026 resource plan projects winter peak demand rising from 4,710 megawatts this year to 6,137 megawatts in 2045. Its high-growth scenario adds about 1,000 megawatts for economic development prospects that are not yet committed. The commission holds a hearing on the plan Nov. 9.
Santee Cooper’s 2026 plan says it evaluated 26 potential large projects ranging from 3 megawatts to more than 800. Since its 2024 forecast, large customers in its territory or that of the cooperatives it supplies have signed contracts totaling more than 550 megawatts of estimated peak demand. The plan does not say how many are data centers.
Santee Cooper had to deliver 5,000 megawatts or more on 24 days this summer, up from six last year, Clay Settle, director of system planning, told its board, The Post and Courier reported. “In these peak times we’re kind of on an island,” he said.
The two utilities plan to share a roughly 2,200-megawatt gas plant at Canadys in Colleton County, approved in June. Its $5 billion cost, about double a 2023 estimate, will be recovered from ratepayers, the newspaper reported.
What it means for business bills
The utilities attribute the rate increases already in motion to other costs.
In May, Dominion settled its rate case, and the commission approved the settlement July 2. Under the commission’s order, a typical household using 1,000 kilowatt-hours a month pays about $11.97 more a month, or 7.62%, before a one-time residential bill credit, with new rates applying to bills starting with the first July billing cycle. Dominion had first sought a 5.91% increase for commercial customers, The Post and Courier reported. It has said the increase is not driven by data centers or Canadys.
Santee Cooper proposed in May average increases of 2.9% for commercial customers in both 2027 and 2028, starting each February, and its board is scheduled to vote on them Oct. 30. Chief financial officer Tami Wilson attributed most of the need to power the utility must buy on the open market until Canadys runs, the newspaper reported. At an Aug. 31 public meeting, Greg McCormack, Santee Cooper’s senior director of financial planning, told the board that 23 customers who commented had named data centers as a concern, according to the transcript.
The merger question
NextEra Energy agreed in May to buy Dominion’s parent company, and the companies say the combined business would have more than 130 gigawatts of “large-load opportunities” in its pipeline. In September they offered Virginia customers a richer package that includes protection from costs tied to serving data centers, The Post and Courier reported. The offer was not extended to South Carolina, the newspaper reported.
“Where are all the concessions for South Carolina?” asked Frank Knapp, chief executive of the S.C. Small Business Chamber of Commerce, according to the newspaper. NextEra CEO John Ketchum told S.C. legislators on Oct. 15, “We are not willing to invest in generation or transmission for data centers if there’s any cost shifting onto residential customers,” The Post and Courier reported. The commission will take public comment on the merger Nov. 12 in North Charleston and is scheduled to rule by Jan. 29, 2027.
Locally, Mount Pleasant Town Council voted Oct. 13 for a two-year moratorium on large data centers, the Moultrie News reported. Colleton County settled a lawsuit this month by agreeing to a data center exclusion zone that includes the ACE Basin, The Post and Courier reported.
How we reported this
We read Duke Energy’s petition and the comments of Dominion Energy South Carolina, Google, the Sierra Club, the S.C. Department of Consumer Affairs, S.C. Appleseed, Nucor and the Coastal Conservation League coalition in Public Service Commission Docket No. 2026-138-E, along with the commission’s scheduling order and workshop notice. We also used the commission’s Order No. 2026-374 approving Dominion’s rate case settlement; the commission’s docket calendars for the workshop, Dominion’s resource plan hearing and the NextEra merger review; Dominion’s 2026 resource plan; Santee Cooper’s 2026 resource plan, current and proposed rate schedules and rate study records, including the transcript of its Aug. 31 board meeting; NextEra Energy’s merger announcement; and reporting by The Post and Courier and its Moultrie News.
