Florida PSC Staff Tells Regulators to Deny Duke Energy’s 50 MW Large Load Tariff, the First Filed Under SB 484
- Data Centers Grid Capacity Regulatory State & Local Regulation
Marin Holt
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- 9 minutes read
- Large load threshold: 50 MW
- Minimum contract term: 20-year
- Study requests above 50 MW: 13
- Smallest request: 160 MW
- Commission vote: November 3, 2026
Florida Public Service Commission staff recommended on October 22, 2026 that the commission deny Duke Energy Florida’s proposed large load tariff as filed, with leave to refile. The tariff, for customers above the 50 MW threshold, is the first filed under SB 484, the data center cost law that took effect July 1, 2026. Commissioners vote on November 3 in Tallahassee, on a docket that had drawn more than 4,400 public comments by October 20.
Duke petitioned on April 22, 2026 for a Large Load Customer Policy, a Large Load Customer Agreement and revised Contribution in Aid of Construction tariffs. The package applies to firm loads with a monthly maximum demand of 50 MW or more at a single location. It sets a 20-year minimum term, a minimum demand of 75 to 85 percent of contract capacity, a minimum load factor of at least 60 percent and a non-refundable $150,000 system impact study fee. Early termination takes two years’ notice and a fee equal to 36 months of minimum bills plus the net book value of new facilities. Security is a percentage of that fee, with a 10 percent floor when the fee exceeds $100 million.
What the package does not do is set a rate. Large load customers would take service under the existing GSD-1 and GSDT-1 schedules until a new rate class takes effect, which Duke targets for January 1, 2028, after its 2024 settlement expires on December 31, 2027. Staff found that the rate freeze in that settlement “only addresses half of the statute.” The other half, that each large load customer bears its own full cost of service, “remains an open question.” Duke “cannot rely on the settlement as a reason to defer an otherwise necessary rate modification until 2028,” the memo states.
Staff’s second ground is scope. The tariff covers only customers who request firm service, and “nothing in the statute supports any such distinction.” Customers who meet the 50 MW definition but take non-firm service would fall outside it. Staff also objected to Section 13.06, which lets Duke negotiate non-material terms without commission review, and to the security formula. It recommends two months of minimum bills instead.
The record shows how little room Duke has. Its witness testified that the utility is able to serve a single 55 MW large load customer before the settlement expires. In discovery Duke reported system impact study requests from 13 customers above the 50 MW threshold, the smallest at 160 MW. Its load hosting analysis found substations and lines able to absorb up to 200 MW, and demand above that triggers upgrades the CIAC mechanism does not cover. Duke has two customers over 50 MW today, and both are grandfathered because they were on the system before December 31, 2025.
Florida Rising’s witness pointed to the parity index of 0.91 approved in the 2024 settlement for GSD-1 and GSDT-1, meaning those classes recover 91 percent of their cost to serve. “Duke’s proposal doesn’t come close and must be rejected,” Earthjustice attorney Bradley Marshall said for Florida Rising at the August 25 hearing, according to Utility Dive. Duke attorney Dianne Triplett countered that “no party has identified a mechanism by which approval of this tariff could increase any customer rates before the end of 2027.” The Florida Industrial Power Users Group, Nucor Steel and PCS Phosphate backed the tariff as filed.
Why It Matters
SB 484 was written to keep data center costs off other ratepayers, and this docket is the first time the commission applies it. Staff offered an off-ramp. If commissioners find the existing rates and protections satisfy the statute, they could approve the cost-recovery framework as an interim step while widening applicability to every customer that meets the definition. Either way, Duke would have 10 business days after the order to refile. Tampa Electric filed its own large load tariff at the end of September with a separate data center class, so the Duke vote sets the template for that case too.
The gap between the 13 study requests and the 55 MW currently available is the real story. Duke’s smallest request is about three times what it says it is able to serve before 2028, so staff expects new generation would be required for any new large load customer. The question of who pays for it lands in the 2027 rate case.
Critical Perspective
Staff’s denial rests on an absence of evidence rather than a finding of harm. The memo concedes that base rates are frozen through 2027 and that no costs shift to other customers before the next rate case. The practical effect is to push every large load contract into that 2027 case, where the 13 study requests above 50 MW, the smallest at 160 MW, meet a system Duke says has 55 MW to spare. Tampa Electric’s filing with a separate data center class is the comparison the commission did not have in August, and the alternative path staff drafted lets commissioners approve the framework anyway. If the commission takes that off-ramp on November 3, what in SB 484 stops Duke from signing contracts up to the 200 MW its lines absorb on GSD-1 rates before any cost study exists?
Sources
- Florida Public Service Commission staff recommendation, Docket 20260064-EI, Item 3 of the November 3, 2026 agenda (Oct 22, 2026)
- Florida Public Service Commission: Commission Conference Agenda, November 3, 2026
- Utility Dive: Duke Energy Florida asks to punt on rate for large load customers (Aug 26, 2026)
- Food & Water Watch release: FL PSC staff to regulators, deny Duke Energy’s data center proposal (Oct 23, 2026)
