ERCOT Set a 91,308 MW All-Time Peak on July 22, 2026. It Just Raised 2027 Transmission Charges for Every Texas Commercial Buyer.
ERCOT's preliminary 91,308 megawatt peak on July 22, 2026 (settled at 91,089 MW after the operating day closed) broke the grid's 2023 record by roughly 6.5 percent. Under PUC Rule 25.192, that single hour is now one of the four intervals that will set every Texas commercial customer's 2027 transmission bill.
Updated August 3, 2026.
The record itself is a headline. The billing consequence is the story.
What happened on the ERCOT grid on July 22, 2026?
ERCOT's system load hit a preliminary 91,308 MW around 5 p.m. Central on July 22, 2026, then settled to an official 91,089 MW after the operating day closed. According to the ERCOT 2026 Peak Demand Records page (updated July 27, 2026), demand records use integrated system load for the full hour, not instantaneous readings. The prior all-time high was 85,508 MW on August 10, 2023, meaning the July 22 hour cleared the old record by more than 5,500 MW.
Reserves stayed well above operating minimums. According to S&P Global (2026), ERCOT ran with more than 10 GW of headroom during the peak hour, and no Energy Emergency Alert was issued at any point during the July 21 to 22 heat event. ERCOT spokeswoman Trudi Webster told reporters the preliminary number was subject to revision through settlement, which explains the later 91,089 MW figure on the official records page.
Solar was a large part of the reason the grid did not tighten further. According to S&P Global (2026), solar generation reached roughly 29 GW during the record hour, up from roughly 10 GW during the August 2023 peak. Doug Lewin, principal at Stoic Energy, summarized the day on X: "Air conditioning demand in extreme Texas heat pushed the ERCOT grid beyond 91 gigawatts today." The grid held. The commercial billing implication is only starting to land.
How does one summer peak hour raise 2027 commercial transmission bills?
Texas allocates the transmission cost of service (TCOS) using the Four Coincident Peak method, or 4CP. The rule is codified in PUC Rule 25.192, the substantive rule that governs transmission service pricing across ERCOT. In plain terms:
- ERCOT identifies the single 15 minute interval with the highest system demand in each of June, July, August, and September.
- Each Distribution Service Provider's transmission allocation is calculated on the average of its demand during those four intervals.
- Each commercial customer's share, its 4NCP (Non Coincident Peak measured coincident with those four system peaks), is set from the same four intervals and applied to the following year's TDU transmission charge.
The July 22, 2026 record is the current July 4CP candidate. Unless August or September posts a system peak that is higher than any July hour, that record hour is locked in as one of the four intervals that will drive 2027 4NCP allocations for every non residential customer whose demand is metered through a Distribution Service Provider.
The ERCOT 4CP data page publishes the running list of monthly candidates in near real time. Commercial buyers on 4CP sensitive rate structures should already be watching that page daily through September 30.
How large is the potential 4NCP impact for Texas businesses?
The TDU transmission charge that flows onto a commercial bill is, in effect, the applicable monthly transmission rate multiplied by the customer's prior year 4NCP demand. That rate is not small. In April 2026, four of the five ERCOT TDUs filed transmission cost of service increases, with approved and pending TCOS updates that raise per kW charges into a range of roughly $8 to $16 per kW month depending on territory and rate class, based on the utility filings summarized in Texas TDU Rate Hike 2026: What Commercial Buyers Should Do.
A worked example. A commercial site that carried an average of 500 kW during the four 2026 summer peak intervals, billed at a blended TDU transmission rate of $12 per kW month, would pay roughly $72,000 in transmission charges over 2027 (500 kW x $12 x 12 months). Cut the coincident demand to 350 kW during the same four intervals, and the 2027 transmission bill drops to roughly $50,400. That is a $21,600 annual delta driven entirely by behavior during four 15 minute windows.
The commodity side is where the exposure gets amplified. On the current TxCP catalog, aggregate rate bands look like this:
| TDU territory | Median commercial rate (cents/kWh) | Sample size |
|---|---|---|
| Oncor | 6.89 | 232 plans |
| AEP North | 7.24 | 171 plans |
| AEP Central | 7.27 | 229 plans |
| TNMP | 7.21 | 211 plans |
| CenterPoint Houston | 7.95 | 152 plans |
Source: texascommercialplans.com live catalog, 1,000 active plans, snapshot August 3, 2026. Those energy rates are the visible number on a commercial bill. Transmission is the line that moves quietly with 4NCP demand and can rewrite a total bill even when the kWh rate does not change.
Can August or September peaks reset the 2026 4CP allocation?
They can, but the bar is now higher than it was on July 21. According to the Texas Tribune (2026), ERCOT's most recent forecast projects state electricity demand could double in six years, with data centers driving most of the growth. Short term, the load ceiling for the remainder of summer 2026 rests on three variables:
- Sustained triple digit heat in the Dallas Fort Worth, Houston, and Austin metros through the second half of August.
- Data center load additions that were queued for interconnection but not fully online during the July 22 event.
- Wind output at the evening ramp, which was near seasonal norms on July 22 and left solar to carry the daylight burden.
If August 2026 posts a hotter absolute peak in the 5 p.m. to 7 p.m. window, that hour becomes July 22's replacement in the 4CP set. If September peaks are lower than July and August, the July 22 hour stays locked in. History skews toward July or August owning the summer record: prior to 2026, the last five ERCOT all-time peaks were set between August 10 and August 20. This year already broke that pattern with a July record.
The Post-Peak 4CP Response Playbook
The July record cannot be undone. What can still be influenced is the customer's own coincident demand during the remaining August and September candidate hours, and the plan structure that will absorb the 2027 transmission increase. Three steps, in order:
- Confirm the July 22 4CP hour. Pull interval demand data from the Smart Meter Texas portal or the customer's ESIID data for hour ending 17:00 CDT on July 22, 2026. Record the site's kW demand during that interval. That number is the current lead candidate for one quarter of the 2027 4NCP allocation.
- Model the August and September response. Identify the site's controllable load categories: HVAC precooling, non essential process load, EV fleet charging, on site storage discharge, standby generation. Estimate the kW curtailment achievable during a 4 p.m. to 7 p.m. ERCOT emergency curtailment call. Model the 4NCP outcome under three scenarios: no action, moderate action (10 to 25 percent load drop), aggressive action (25 percent plus).
- Mitigate on the commodity side. Solicit fixed price offers on the commodity portion of the electricity bill so that any 2027 TDU pass through lands on a stable energy rate rather than compounding with a variable one. Short term contracts on the current TxCP catalog run at a median 9.90 cents per kWh compared with 6.98 cents on long term, a 42 percent spread that widens the impact of any transmission increase for buyers who do not lock in.
For a broader forward look at the summer, see ERCOT Demand Up 14 Percent: What Texas C&I Buyers Must Do This Summer.
What this means for Texas commercial buyers
The July 22, 2026 record broke the ERCOT all-time high by more than 5,500 MW, held with double digit reserves in place, and set a July 4CP candidate that will very likely stay in the final 2026 set. Under PUC Rule 25.192, that hour becomes one of the four inputs to every commercial customer's 2027 4NCP allocation. The commodity market has responded predictably: short term commercial rates on the TxCP catalog currently sit 42 percent above long term rates, a spread that widens the total bill exposure for any buyer who leaves both transmission and energy charges variable heading into 2027.
Data-driven decisions here favor the buyers who verify their July 22 interval demand, model an achievable August and September response, and lock the commodity portion before the 4CP hunt ends on September 30.
Frequently Asked Questions
What was ERCOT's peak demand on July 22, 2026?
ERCOT's system load hit a preliminary 91,308 MW around 5 p.m. Central on July 22, 2026, then settled to an official 91,089 MW after the operating day closed. Either figure cleared the previous all-time record of 85,508 MW (August 10, 2023) by more than 5,500 MW.
How does the July 22 peak affect my 2027 commercial electricity bill?
Under PUC Rule 25.192, ERCOT identifies the single 15 minute interval with the highest system demand in each of June, July, August, and September. Those four intervals average to a Four Coincident Peak (4CP). Every commercial customer's demand during those same four intervals sets its 4NCP allocation, which is applied to the following year's TDU transmission charge. The July 22 hour is currently the July 4CP candidate for 2026, so it flows into 2027 transmission billing.
What is 4CP and how is it calculated?
4CP is the Four Coincident Peak methodology codified in PUC Rule 25.192. ERCOT selects the highest system-load 15 minute interval from each of June, July, August, and September. Each Distribution Service Provider's transmission allocation is calculated on the average demand during those four intervals, and each commercial customer's 4NCP is measured during the same four hours.
Can August or September peaks replace the July 22 4CP hour?
Yes, but the bar is high. A new July 4CP replacement would require a single 15 minute interval in August or September 2026 that exceeds the July 22 record. If neither month posts a higher system peak, the July 22 hour stays locked in as one of the four 2026 intervals used to bill 2027 transmission service.
What should I do now to reduce my 2027 transmission bill?
Three steps. First, pull interval demand data from Smart Meter Texas for hour ending 17:00 CDT on July 22, 2026 to confirm your kW during the current July 4CP candidate. Second, model an August and September curtailment plan (HVAC precooling, non essential process load, EV fleet charging, on site storage discharge) against realistic 4 p.m. to 7 p.m. call windows. Third, solicit fixed price commodity offers so any transmission increase lands on a stable energy rate.