ERCOT Under-Frequency Load Shedding Goes to Five Stages on November 1, Doubling the Required Automatic Cut at 59.1 Hz for Texas Commercial Sites
ERCOT confirmed that automatic load shedding moves from three standard stages to five on November 1, 2026. No electricity plan changes a site's exposure, but larger flexible loads can get paid to drop first.
On November 1, 2026, ERCOT's under frequency load shedding program expands from three standard stages to five, and the minimum automatic cut required when grid frequency falls to 59.1 Hz doubles from 5% to 10% of each Transmission Operator's load. ERCOT announced the date on September 30, 2026 and repeated it to Transmission Operators on October 20. For Texas commercial buyers the point is simple: no electricity plan changes whether your meter sits on a relay that trips in under half a second, but some larger sites can get paid to drop first.
Key takeaways:
- Under frequency load shedding (UFLS) is the automatic, relay-driven last resort that disconnects customer circuits when ERCOT frequency falls below 59.3 Hz. Rolling blackouts are the manual version, ordered during an Energy Emergency Alert Level 3.
- From November 1, 2026, the required cumulative cut is 5% at 59.3 Hz, 10% at 59.1 Hz, 15% at 58.9 Hz, 20% at 58.7 Hz and 25% at 58.5 Hz. The 25% total does not change.
- The rules are not new. The Public Utility Commission of Texas (PUCT) approved them in January and October 2023. November 1 is the date they finish going live.
- Separate 59.5 Hz "anti-stall" stages arrive at the same time, and they are optional for each utility.
- None of the 13,664 commercial plans we tracked on October 19, 2026 changes a site's UFLS exposure. The feeder your meter is on decides that.
What Happened
ERCOT Market Notice M-A093026-02, sent to Transmission Operators (TOs) on October 20, 2026, confirms that Nodal Operating Guide language from two revision requests, NOGRR226 and NOGRR247, will be implemented on November 1, 2026. It repeats Notice M-A093026-01, which gave all market participants the same date on September 30. In ERCOT's words, the two changes "include new anti-stall Under-Frequency Load Shed (UFLS) stages and expand UFLS from three standard stages to five." TOs are the utilities that arm the relays.
Primary sources: the ERCOT implementation notice, the NOGRR247 rule page and the NOGRR226 rule page.
What is under frequency load shedding?
Under frequency load shedding is an automatic grid-protection scheme in which relays at utility substations open preselected distribution circuits when system frequency drops below set thresholds. ERCOT's grid runs at 60 Hz. When a large block of generation trips offline faster than reserves can respond, frequency falls. UFLS then removes load until supply and demand balance again. Section 2.6.1 of the ERCOT Nodal Operating Guide sets the thresholds, and NOGRR247 adds a minimum delay of six cycles (0.1 seconds) before a relay trips.
What changes in the stage table on November 1?
The 25% total does not move, but the steps get smaller and more frequent. ERCOT's April 6, 2026 UFLS survey notice shows relays already sit at five set points. The required relief, though, still steps up at only three of them: 5%, 15% and 25%. From November 1, each stage adds a uniform 5%.
| Frequency | Cumulative cut required today | Cumulative cut required from Nov 1, 2026 |
|---|---|---|
| 59.3 Hz | At least 5% | At least 5% |
| 59.1 Hz | At least 5% | At least 10% |
| 58.9 Hz | At least 15% | At least 15% |
| 58.7 Hz | At least 15% | At least 20% |
| 58.5 Hz | At least 25% | At least 25% |
Under NOGRR247, each percentage is a share of the TO's load as measured at the moment frequency reaches 59.5 Hz.
Is the 59.5 Hz anti-stall stage mandatory?
No, the anti-stall stage is optional for each utility. NOGRR226, sponsored by LCRA in May 2021, lets TOs add stages at 59.5 Hz that trip after a sustained sag rather than a sharp drop. The relief is at least 1.5% of TO load after 90 seconds, 3.0% after 120 seconds and 4.5% after 150 seconds. The guide says TOs may, but are not required to, provide it. The stage targets the slow, stuck-frequency pattern that nearly toppled the grid in February 2021.
Why did ERCOT add stages after Winter Storm Uri?
Winter Storm Uri showed how close a stalled frequency can come to a total blackout. ERCOT's February 24, 2021 board presentation reported that frequency bottomed at 59.302 Hz on February 15, 2021. It stayed below 59.4 Hz for 4 minutes and 23 seconds. Under the generator protection settings described in the FERC and NERC staff report on the event, units could trip if frequency stayed below 59.4 Hz for 9 minutes. ERCOT's ordered load shed peaked at 20,000 MW that week. Finer UFLS steps let the automatic scheme drop less load in a moderate event and catch a slow sag earlier.
Where do Texas utilities stand on implementation?
Most of the work is already done. ERCOT's 2026 UFLS survey was presented at the October 1, 2026 Reliability and Operations Subcommittee meeting. It measured 52,790 MW of load at the May 6, 2026 test hour and found 10.02% of load armed at 59.1 Hz and 22.34% at 58.7 Hz, already at or above the November 1 minimums. ERCOT reported that all TOs had started work on the new stages and six had confirmed full implementation.
How Is Under Frequency Load Shedding Different From ERCOT Rolling Blackouts?
Rolling blackouts are manual and rotated, while under frequency load shedding is automatic and instant. ERCOT orders rotating outages during an Energy Emergency Alert Level 3, normally after moving through lower alert levels. Utilities such as Oncor, CenterPoint, AEP Texas and TNMP then rotate blocks of customers. UFLS fires inside half a second with no warning at all, because once frequency reaches 59.3 Hz there is no time for an instruction.
That distinction matters for planning. A rotating outage usually gives a business a few minutes of public alerts to shut equipment down in order. A UFLS trip looks like a breaker opening upstream. Everything on that circuit goes dark at once and stays off until frequency recovers and the utility restores it.
Impact on Commercial Electricity Buyers in Texas
The November 1 change does not touch rates, bills or contracts, but it does make a moderate frequency event drop twice the required load at 59.1 Hz. We see three channels where it reaches a commercial account.
Your plan does not decide your exposure. UFLS relays sit on utility feeders, so a fixed-rate, indexed or month-to-month plan from any Retail Electric Provider (REP) carries identical outage risk. The TxCP Commercial Rate Index (TCRI) sat at 7.06 cents per kWh across 13,664 plans on October 19, 2026, and not one of those plans changes the physics. A fixed price protects what you pay per kWh during a grid emergency. It does not keep the lights on.
A critical load designation is not an exemption. Oncor, CenterPoint, AEP Texas and TNMP all warn that critical care and critical load status does not guarantee uninterrupted service. The PUCT's study of ERCOT load shed protocols notes that utilities' feeder-level UFLS details are treated as confidential critical infrastructure information. In practice, a business generally cannot look up whether its circuit is armed.
The paid alternative is to drop on purpose. ERCOT Nodal Protocols require Load Resources providing Responsive Reserve Service (RRS) to set their own under-frequency relays no lower than 59.70 Hz. That trips them well before the first UFLS stage at 59.3 Hz, and those sites earn the RRS capacity clearing price through their Qualified Scheduling Entity. Emergency Response Service (ERS) is the slower, contracted option. Its winter round needs site data by October 30, 2026, as we covered in our ERCOT ERS winter bidding explainer.
The TxCP Frequency Exposure Check: Four Questions for Your Site
The TxCP Frequency Exposure Check is a four-question test we use to size what an automatic load shed event would cost a commercial site and whether that site could be paid to avoid it. Run it once a year, and again whenever a site changes equipment or utility.
1. Is the meter on a UFLS-armed feeder?
Ask your utility directly. It may decline to confirm, so plan as if the answer is yes.
2. What fails in the first half-second?
List equipment that cannot tolerate an instant loss: refrigeration controls, point-of-sale systems, servers and process lines. Check whether a UPS or automatic transfer switch covers each one.
3. Could this load get paid to drop first?
A site with flexible load may qualify as an RRS Load Resource or an ERS resource. Qualification runs through a Qualified Scheduling Entity and requires metering ERCOT can verify, so price the revenue against the disruption.
4. Does the energy contract mention curtailment?
Confirm that enrolling in a demand response program does not conflict with your REP agreement. Remember that a fixed price covers only the price.
What You Should Do
Use the week before November 1 to turn this change into four concrete checks, because no utility or REP is likely to contact a typical commercial account about it.
- Pull your latest bill and Electricity Facts Label, and note your TDU: Oncor, CenterPoint, AEP Texas Central, AEP Texas North or TNMP.
- Ask your TDU account representative whether your service is on an automatic under-frequency circuit and how restoration works after a trip.
- Test backup power by confirming UPS runtime and generator transfer time on the loads you listed in the Frequency Exposure Check.
- If your site can shed load on command, ask about Load Resource or ERS participation before the next enrollment window. Our December 2026 MORA breakdown shows when winter grid risk peaks.
Questions to Ask Your REP or Broker
These four questions separate an offer that accounts for grid emergencies from one that only quotes a price per kWh, and most providers can answer them in a single call.
- Does anything in this contract change if our site is shed by UFLS or a rotating outage?
- Can we enroll in ERS or as a Load Resource without breaching this agreement, and who keeps the revenue?
- Do you provide interval data that would support a demand response application?
- Which charges on our bill recover past grid emergency costs, such as the Winter Storm Uri securitization charges, and when do they end?
For the full picture, see our Texas commercial electricity rates overview. See every commercial plan we track in our data download.
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Frequently Asked Questions
What is under frequency load shedding in ERCOT?
Under frequency load shedding is ERCOT's automatic last-resort protection. Utility relays disconnect preselected circuits when grid frequency falls to 59.3 Hz. From November 1, 2026, it runs in five stages from 59.3 Hz down to 58.5 Hz and sheds at least 25% of each Transmission Operator's load in total.
What changes on November 1, 2026?
ERCOT implements NOGRR226 and NOGRR247. The required cumulative cut rises from 5% to 10% at 59.1 Hz and from 15% to 20% at 58.7 Hz. Every stage gets a minimum 0.1-second delay, and utilities may add optional anti-stall stages at 59.5 Hz.
Is under frequency load shedding the same as a rolling blackout?
No. Rolling blackouts are rotating outages that ERCOT orders during an Energy Emergency Alert Level 3. Under frequency load shedding is automatic, trips in under half a second, and fires only when frequency itself falls to 59.3 Hz.
Does a fixed-rate electricity plan protect a business from load shedding?
No. Exposure is set by the utility feeder a meter sits on, and none of the 13,664 commercial plans we tracked on October 19, 2026 changes it. A fixed rate protects the price you pay. Larger flexible loads can earn RRS or ERS payments for dropping first.