ERCOT Probes Nearly 10 GW of Sub-75 MW Data Center Projects

The Electric Reliability Council of Texas (ERCOT) is investigating whether data center developers shrank proposed projects below 75 MW to avoid its large-load review, the San Antonio Express-News reported on Nov. 6.

Chad Seely, ERCOT's senior vice president of regulatory policy and general counsel, told the Public Utility Commission of Texas (PUC) that nearly 10 GW of projects classed as medium loads, which run from 25 MW to just under 75 MW, are working with utilities directly. ERCOT sees a substantial concentration of them between 60 MW and 74.9 MW, the newspaper said.

ERCOT has sent 132 requests for information to transmission and distribution service providers about those medium projects, asking for each one's size, location and energization date. Seely said the findings could lead the commission to consider rules for loads under the 75 MW line. He also warned that many more sub-75 MW data centers would pose a risk to transmission planning and to grid operations.

Why the 75 MW line matters

Projects of 75 MW or more go through ERCOT's large-load process, including Batch Zero, its one-time study of the large loads seeking to connect. Smaller projects can negotiate with their utility instead. For a developer, a 74 MW site avoids the grid operator's study queue and its eligibility checks, which is why a cluster just under the cutoff draws scrutiny. Neither the Express-News nor ERCOT has said that any developer resized a project for that reason; the review is meant to find out.

For the grid, a block of nearly 10 GW sitting outside the large-load study is also a planning question. The Express-News put ERCOT's record peak demand at 91.31 GW, set in July, so the medium-load pipeline alone is roughly a tenth of that peak, although proposed capacity is not confirmed demand.

The audit behind it

The probe sits inside the verification and audit that Gov. Greg Abbott ordered on Aug. 3. That day ERCOT paused the Batch Zero study and paused approvals to energize data centers and crypto-mining sites of 75 MW or more, according to ERCOT's September board slides. The pause is background, not new; what is new is the look at projects below the line.

ERCOT's board slides from Sept. 14-15 said 204 projects totaling 66.4 GW were conditionally classed as base load and 158 projects totaling 127.9 GW as studied load. The first audit round went to more than 257 developers, all of whom answered, the Express-News said, and ERCOT is working through roughly 5,100 questions and answers. A second round, with a five-business-day deadline, is going to about 80% of those developers and asks about site control, long-lead equipment and financial security.

Separately, a community impact questionnaire covered about 465 projects, and developers of 433 responded, requesting 177 GW in total. That is nearly twice the 91.31 GW record peak, but it is proposed capacity.

What comes next

ERCOT will file its Batch Zero eligibility verification report and its community impact review report with the PUC by Dec. 10, according to its slides. Seely said the audit report is expected to run about 150 pages and be discussed at the PUC's Dec. 17 meeting. Disputes are likely if loads are found ineligible, he told commissioners.

ERCOT has not said how the audit will change the Batch Zero study timetable; its slides call the impact to be determined. Voltgrid has followed the politics around the pause, including Hinojosa's moratorium pledge and CoreWeave's request to the governor-elect. Watch whether the PUC opens a rulemaking on the 25 MW to 75 MW band after Dec. 17.