Texas PUC Approves “Ride-Through” Rules For Data Centers

By Diana DiGangi of UtilityDive,

The Texas Public Utility Commission on Thursday unanimously approved rules that will require large computational loads, like data centers and crypto-mining facilities, within the Electric Reliability Council of Texas footprint to stay stable and connected to the grid through disruptions.

Modern computational loads, Kenteel Engineering said in a June blog, are “engineered to protect extremely sensitive and expensive equipment,” and during a voltage dip are programmed to disconnect or enter momentary cessation.

However, this presents a reliability problem, Kenteel Engineering said, as when “several hundred — or several thousand — megawatts of computational load all detect the same sag and drop simultaneously, the grid experiences a sudden, large loss of demand.”

“As LCLs increase on the ERCOT System, similar events would be expected to increase in magnitude and frequency, leading to frequency instability and other reliability problems absent frequency and voltage ride-through requirements,” the Texas PUC rules state. 

The rules don’t immediately penalize facilities that fail to ride through a qualifying event, Kenteel Engineering noted, but instead put them “on the clock” to investigate and report the root cause within 90 days of ERCOT’s request, “develop a corrective plan within 90 days of completing that investigation, and implement the approved plan within 180 days unless ERCOT grants more time.”

“Overriding all of that, if ERCOT judges that continued operation poses an imminent risk to local or system reliability, it can order the [large electric load] — and keep it disconnected — until the Customer demonstrates compliance to ERCOT’s satisfaction,” Kenteel Engineering said.

In comments, the Data Center Coalition argued that the PUC lacks the statutory authority to “impose the binding and ongoing operational requirements contained in [the rules] directly on retail customers — a category of entity that the Legislature deliberately excluded from ERCOT’s authority.” 

Texas Industrial Energy Consumers made similar comments, writing, “Unlike Market Participants who must agree to comply with and be bound by all ERCOT Protocols as a condition of participating in the wholesale market, pure retail loads have made no such commitment and have no such obligation.”

TIEC also argued that ERCOT lacks the expertise to “develop reasonable operational requirements for complex, costly manufacturing equipment. It is completely inappropriate to give ERCOT the ability to directly regulate businesses who are not participating in the wholesale market and are not otherwise regulated entities.”

In a staff memo from the PUC’s R. Floyd Walker, senior counsel with the commission’s market analysis division, Walker dismissed concerns over the PUC’s authority. Those commenters “seem to be working under the assumption that explicitly statutory authority is required,” he wrote. “Staff respectfully submits that delegated authority is sufficient.”

“There is no debate that voltage and frequency excursions on the transmission network create reliability concerns, which increase with the interconnection of each new large computational load,” Walker said. “Accordingly, if approved by the Commission, the provisions of [the rules] would be within ERCOT’s authority by virtue of that approval.”

Comments from the Texas Blockchain Council argued that proposed mitigation approaches for LCLs, such as the installation of dedicated battery storage, “are neither practical nor economical at scale.”

“While battery solutions have been suggested, we are not aware of any that have been successfully tested or deployed at the scale required for [LCLs],” the group wrote. “Even if pursued, mandating dedicated batteries for each facility would be unlikely to fully resolve the underlying technical challenges and would impose substantial costs, currently estimated at more than $1.6 million per MW, making such an approach economically prohibitive for most operations.”

ERCOT staff approved of the rules, writing in a market impact statement that they provide “necessary requirements to reduce the reliability risk posed by LCLs unexpectedly tripping or transferring to backup generation when frequency and voltage excursions within a specified range occur.”

In official comments, ERCOT wrote that LCL loss wasn’t a hypothetical, and ERCOT “has experienced 28 events involving LCL trips of at least 100 MW due to voltage and frequency excursions since the beginning of 2023. This risk will increase exponentially with the significant growth of LCLs expected in the ERCOT Region.”

Developers have requested studies for more than 438 GW of large load projects within ERCOT’s footprint, and “even if only a small fraction of these projects materialize, this will significantly increase the risk that cascading outages could occur due to LCL failures to ride through typical voltage or frequency disturbances,” ERCOT said.