Three ERCOT 4CP Peaks Remain in Summer 2026 and They Will Set 2027 Commercial Transmission Bills
Energy analyst Doug Lewin reported ERCOT crossed 83,000 megawatts for the first time in 2026 on July 11, putting the day in contention for the summer 4CP set that will drive 2027 commercial transmission bills. Three peak windows remain.
What 4CP Means for Your 2027 Commercial Electricity Bill
4CP is the ERCOT method for setting the transmission demand portion of large commercial and industrial electric bills. Each year, ERCOT records the hour of highest system demand for each calendar month from June 1 to September 30. The four highest of those hours become the 4CP hours. Your site's demand during those four hours sets a 4CP tag that drives demand charges you will pay every month for the following calendar year.
For commercial and industrial sites with a high load factor, the 4CP demand charge can exceed the energy charge on a monthly bill. It is a fixed contribution to a moving grid cost, and once the four peak hours are locked in for a summer, the tag carries over for the entire next year.
Why July 11 Made the Watch List
Doug Lewin, an energy analyst, reported on X that ERCOT reached 83,000 megawatts for the first time in 2026 on July 11. For comparison, ERCOT's 2025 summer peak was 83.9 gigawatts, and the all-time record is 85,508 megawatts set on August 10, 2023. The ERCOT Demand and Energy Report will finalize the exact hourly value. The precise number is not the point for commercial buyers. A hot afternoon with muted west Texas wind in mid-July is exactly the kind of hour that has landed in the 4CP set in nearly every summer of the last decade.
A candidate 4CP day this early in the season is a warning shot. The remaining peak measurement windows are the tail of July, all of August, and September.
Three More Peaks Are Coming
ERCOT's monthly system peaks for July, August, and September have historically aligned under the same conditions: statewide temperatures in the mid-90s and above, muted west Texas wind, and a demand ramp between 3 and 7 pm. Fresh heat waves through the last week of July and the first three weeks of August are the highest-risk 4CP windows in most years. September peaks tend to land on hot early-month afternoons after the Labor Day cooldown fades.
For commercial buyers, the practical read is straightforward. If your site does not have a documented plan to respond to ERCOT's next Watch, Advisory, or Emergency Notice this summer, the odds are you will contribute to the 4CP set through pure inaction.
The Peak-Shaving Playbook
Four levers still work in the remaining 4CP window.
- Voluntary curtailment. Publish an internal peak-hour protocol. When ERCOT's 6-day peak forecast crosses a threshold you set (many operators use 80,000 MW), shed discretionary load from 3 to 7 pm. This can be as simple as raising HVAC setpoints and delaying production that is not time-sensitive.
- Battery dispatch. Behind-the-meter storage that discharges during forecast peak hours cuts the 4CP tag directly. Even a one-hour battery sized to your peak hourly demand can materially reduce the tag.
- Onsite generation. Natural gas gensets or reciprocating engines dispatched during 4CP hours reduce net grid load while keeping operations running. The Public Utility Commission of Texas finalized rules in June for the Texas Backup Power Package, which offers grants up to 500 dollars per kilowatt for qualifying critical facilities to install behind-the-meter generation.
- Load scheduling. Move compressors, pumps, EV charging, and other flexible loads outside the 3 to 7 pm window. In multi-shift operations, shifting batch or process loads from second to third shift can drop peak-hour demand meaningfully.
Where the Commercial Market Sits This Week
As of July 14, 2026, the TxCP live dataset shows 484 active commercial electricity plans across all five ERCOT-linked TDU territories. The overall average energy rate is 10.7 cents per kilowatt-hour.
The contract-length picture is unusually wide right now:
- Short-term plans (12 months or less), 347 plans: median 12.5 cents per kWh, average 11.7 cents.
- Mid-term plans (12 to 24 months), 60 plans: median 7.9 cents per kWh, average 8.3 cents.
- Long-term plans (24 months or more), 39 plans: median 8.0 cents per kWh, average 7.8 cents.
Per-TDU medians for the current catalog:
- CenterPoint: 9.2 cents per kWh
- Oncor: 9.9 cents per kWh
- AEP Central: 10.6 cents per kWh
- TNMP: 11.9 cents per kWh
- AEP North: 11.9 cents per kWh
These aggregate figures include the energy charge only. The 4CP transmission demand charge is billed separately by the TDU and is set by the summer peak-hour behavior of the individual site.
Bottom Line
If your commercial site is on a demand-billed rate, the four highest ERCOT peak hours between June 1 and September 30 will shape your 2027 transmission bills. July 11 is a candidate 4CP hour under review. Three more peak windows remain: late July, August, and September. Curtailment, battery dispatch, onsite generation, and load scheduling are the levers that still work in the remaining window. Nothing you do in October will move the 2027 tag.