• NPM SIGNALS now tracking LL tariffs
• LL tariff cases under review have risen to 104, up from 77 last quarter

Smart Electric Power Alliance (SEPA) and the NC Clean Energy Technology Center (NCCETC) have published their most recent quarterly update on the many large load tariffs currently under consideration in the US.

Driven mostly by the ongoing country-wide data center buildout, utilities are experiencing an increase in electricity demand like nothing that’s been seen before.

With this in mind, many utilities are developing new tariffs for customers wanting to connect new large load projects to the grid. The main aim of these new tariffs is to ensure that customers are responsible for the costs associated with building the infrastructure required to connect new large loads.

The most recent update from SEPA and NCCETC outlines the details of 104 approved and pending large load tariffs, which are up from 77 last time around.

Further details and NPM coverage of the most notable additions having occurred during the second quarter of 2026 can be found below.

The spreadsheet is attached to this article and also covered in NPM signals.

WEC Energy’s VLC tariff

As reported by NPM towards the end of May, WEC Energy received long-awaited final approval from the Public Service Commission (PSC) of Wisconsin of its very large customer (VLC) tariff.

The proceeding generated huge interest, with the PSC having received over 2,000 individual comments from members of the public. As with the majority of these cases, concerns centered on data center development costs being transferred to existing customers.

After much debate, commissioners at the PSC ultimately decided upon an eligibility threshold of 100MW, despite WEC Energy pushing for a much higher threshold of 500MW.

Following its approval, Oracle filed a lawsuit against the Wisconsin PSC, arguing with the new rules imposed excessive credit and security obligations. As part of the new tariff, developers with credit ratings below A- are required to post a substantial letter of credit or cash deposit.

As part of its lawsuit, Oracle described these requirements as creating “harmful and unintended consequences that will force significant investment outside of Wisconsin.”

Despite this, Oracle voluntarily dropped its lawsuit against the state regulator during August.

Tri-State G&T High Impact Load Program

Also reported by NPM during the period was Tri-State Generation & Transmissions’s (Tri-State) amended large load proposal, which it submitted with the Federal Energy Regulatory Commission (FERC) during April.

Known as the High Impact Load Program, Tri-State G&T submitted an initial proposal with FERC during August 2025. However, this was rejected after the regulator found it to be encroaching on retail rate regulation, which is something that falls outside of FERC’s authority.

As part of its renewed proposal, Tri-State removed requirements for the terms of energy sales from utility members to customers.

Tri-State set a 45MW threshold for the tariff and included provisions such as security payments, minimum terms and minimum monthly demand and energy charges.

The new program was approved by FERC on August 14, 2026, subject to Tri-State outlining within 30 days how it plans to process certain HILP agreements to members in the Eastern Interconnect.

As part of a press release announcing FERC approval, Tri-State CEO Duane Highley described the new tariff as helping to “drive economic development across [its] member systems, manage the risks of large load growth and meet regulatory requirements.”

Duke Energy Florida

Signed into law by Governor Ron DeSantis on May 7, 2026, Senate Bill 484 impacted ongoing utility processes to develop new large load tariffs, including those under development by Duke Energy Florida.

The new legislation came into force on July 1 and requires investor-owned utilities (IOUs) within Florida to develop new tariffs for large loads, ensuring that customers behind projects fund all associated costs.

This includes any costs relating to connection, O&M alongside any future transmission and generation requirements.

In response to the legislation, Duke Energy Florida withdrew its under-consideration proposal for large loads and became the first IOU in the state to file a renewed proposal at the end of last month.

The new proposal was discussed at a Florida Public Service Commission public hearing held on August 25, 2026.

During the discussion, PSC General Counsel representative Walt Trierweiler described Duke Energy’s proposal as not complying “with the most basic provisions of SB 484.” The PSC is expected to vote on the proposal towards the end of the month.

All IOUs in Florida – including Florida Power & Light, Florida Public Utilities Company, and Tampa Electric Company (TECO) – are required to file proposals adhering to the provisions of SB 484 with the PSC by October 1, 2026.

NPM is tracking 51 data center developments in the State of Florida, 18 in Wisconsin and 33 in Colorado.