ERCOT says it will recommend that its Board of Directors approve a reliability-must-run (RMR) contract for one of three aging CPS Energy gas units, set for retirement, to maintain reliability in the San Antonio area.

The grid operator also told the Texas Public Utility Commission during its Nov. 21 open meeting that it is working with CPS and CenterPoint Energy to determine whether the latter’s controversial $800 million mobile generators could be moved to San Antonio as an alternative.

“I think this is an elegant solution to a number of issues that we’re facing,” PUC Chair Thomas Gleeson said in response.

CenterPoint’s 2021 lease of 15 32-MW generators and 13 smaller ones (between 1.2 and 5 MW) became a source of derision and political criticism when they went largely unused during the utility’s weekslong restoration after Hurricane Beryl. (See Texas Politicos, Residents Bash CenterPoint.)

ERCOT General Counsel Chad Seely told the PUC that grid operator staff, the two utilities and Life Cycle Power, the generators’ owner and operator, have been discussing moving the larger units and their 480 MW of capacity to the San Antonio area. He said the 15 large generators are the equivalent of two of the retiring plants, Braunig Power Station’s Units 1 and 2, and would provide greater reliability than CPS’ forced outage-prone assets.

That comes from “mainly the diversity of where those units can be located versus having two larger units that have the susceptibility of higher forced outages,” he said. “These are dual-fuel-capable units. They could be located in San Antonio with a higher shift factor. And obviously their start time is about 10 to 15 minutes, versus a longer lead time for Units 1 and 2.”

CenterPoint said in an emailed statement that its “top priority is finding a Texas-driven solution that helps address the growing energy needs of Texans and our strong economy.”

“We are optimistic that we will find a constructive solution that best serves our customers and Texas,” the utility said.

San Antonio’s municipal utility told ERCOT earlier this year that it planned to retire the three Braunig units, which date back to the 1960s, in March 2025. However, ERCOT said the resources, with a combined summer seasonal net maximum sustainable rating of 859 MW, were needed for reliability reasons and issued a request for RMR proposals in July. (See ERCOT, CPS Energy Negotiating RMR, MRA Options for Retiring Units.)

In the meantime, Seely said ERCOT will urge its board to approve an RMR agreement for Braunig Unit 3, the newest (1970) and largest (412-MW maximum summer rating) of the three units. It will ask the directors to defer any decision on the other two units so staff can continue to work on the feasibility of the mobile generators’ move. The board meets Dec. 2-3.

CPS has said each unit must be inspected and repaired — consecutively, not concurrently — if it is to operate beyond its retirement date. The utility has moved the unit’s suspension date up to March 2, allowing time for inspection and repairs that it says will take at least 60 days.

“If the board moves forward with an RMR agreement, that will allow us to move forward with that inspection work at the beginning of March in trying to get that unit back for the summer of 2025,” Seely said. “A lot of work has been done on the technical side. We do believe it is technically feasible to move those 15 units into the San Antonio area.”

“There are many factors being evaluated by ERCOT and the companies involved,” CPS spokesperson Miguel Vargas told RTO Insider in an email. “We remain engaged in ERCOT’s efforts to evaluate this alternative proposal.”

ERCOT says the RMR units will be important in addressing the South Texas export interconnection reliability operating limits staff established this year that will eventually be resolved by transmission projects underway. Their analysis revealed that under certain conditions, such as when high system demand coincides with an outage of a major transmission line or one or more generation units, lines that deliver power from South Texas into San Antonio could be overloaded and possibly lead to cascading outages.

ERCOT’s solicitation for must-run alternatives to Braunig’s retiring units resulted in one response. A 200-MW multi-hour energy storage resource responded within minutes of an Oct. 7 deadline, proposing to start in the summer of 2026 and end March 1, 2027.

The RMR contract would be ERCOT’s first since 2016. The grid operator entered into an agreement with NRG Texas Power over a previously mothballed gas unit near Houston. It ended in 2017, thanks partly to transmission facilities that increased imports into the region.

New Rules for Crypto Miners

The PUC approved a new rule requiring virtual currency mining facilities in ERCOT to annually provide information related to their electricity demand, location and ownership, giving the grid operator more transparency into the market (56962).

Under the rule, cryptocurrency miners with a total load above 75 MW will have to register with the PUC as a large flexible load, capable of adjusting their power consumption in response to prices. The facilities must file a five-year projection of expected peak load for each year, including the percentage of load that meets the definition as interruptible. The rolling five-year projection will be repeated each year.

“I think it’s really important that, as we’re looking at [Texas’] load growth, that this help us give ERCOT and the market an understanding of what those actual projections are from the cryptocurrencies’ standpoint,” Commissioner Jimmy Glotfelty said. “Having them look five years out every year is a really important component of this for reliability.”

The rule was mandated by state law as demand associated with virtual currency mining operations has grown rapidly in recent years, according to the U.S. Energy Information Administration.

PUC Completes Beryl Investigation

The commission approved several reports, including its investigation into two major weather events that hit the Houston area: a derecho in May and Hurricane Beryl in July.

At Gov. Greg Abbott’s directive, the PUC assessed local utilities’ emergency preparedness and their response to the two events (56822).

The PUC team made a number of recommendations to reduce the length and effect of power outages, including annual hurricane and storm drills between utilities, new performance standards and heavier fines, and a legal right to restoration timelines.

The investigation’s summary will be added as an addendum to the broader report that all state agencies are required to file ahead of Texas’ biennial legislative sessions. The 2025 session begins Jan. 14.

The PUC also approved:

• • ERCOT’s biennial report on the operating reserve demand curve, which will eventually be replaced by individual ancillary service demand curves under real-time co-optimization (55999); and
  • an order finding ERCOT’s proposed ancillary service methodology for 2025 is appropriate and necessary for the market’s proper functioning (54445).