ERCOT 12CP: Why Texas is Moving from 4CP to Monthly Coincident Peaks

Every summer, Texas' largest electricity users play a high-stakes game, trying to reduce their load when they think the grid will be at its peak. Now the game is changing.

Why is ERCOT moving to 12CP?

The Public Utility Commission of Texas (PUCT) established the Four Coincident Peak (4CP) program to incentivize commercial and industrial operations to reduce demand during peak times in the four hottest months (June, July, August, and September). In the 20+ years since then, companies have established various strategies to predict the peaks and curtail load accordingly.

Today, round-the-clock ERCOT load growth, increasing winter peaks, and growing shoulder-season reliability concerns (driven by maintenance outages) are forcing the grid operator to expand its coincident peak program.  

The PUCT is moving to replace the four-coincident-peak (4CP) methodology with a twelve-coincident-peak (12CP) framework. Regulators are expected to finalize the new program rules by December 31, 2026, with the goal of allocating transmission costs more smoothly.  

ERCOT 12CP vs. 4CP

Under the current system, ERCOT-wide transmission costs are allocated to distribution service providers (DSPs), the "wires" companies that deliver power to end users, based on their demand during the highest-traffic 15-minute periods on the transmission grid each month from June to September.

The 12CP framework changes the equation substantially. The proposed rule would measure twelve 30-minute grid peaks, one per month for the entire year, rather than four 15-minute peaks crammed into the summer months.  

When will ERCOT change to 12CP?

The date many are circling is December 31, 2026, but that's not the policy effective date. Senate Bill 6 simply requires the PUCT to complete its evaluation and amend its rules by then.  

As of this writing in August 2026, no one yet knows when the new program will go live. If the rule is finalized ahead of schedule, it's theoretically possible that 12CP measurements could begin in late 2026, with those costs starting to show up on utility bills in 2027.

More likely, measurement will start in 2027 or later, with costs showing up the year after. What's clear is that nothing in the statute says there has to be a grace period. The PUCT could dictate that the first measured month be shortly after, or potentially even backdated from, the final rule.

How will the shift to 12CP affect Texas energy users and utilities?

Large industrial and commercial customers will lose a playbook they’ve spent twenty years refining. Under 4CP, a business that could shed load across just four summer afternoons (assuming perfect foresight) could cut its transmission bill dramatically for the entire year.  

This meant that a fairly modest amount of operational flexibility bought an outsized reward. Under 12CP, that same business has to shift their load at least 12 times, including winter mornings and mild shoulder-season days nobody currently bothers to watch.  

PUCT Chairman Thomas Gleeson has also discussed pairing the 12CP shift with a minimum demand charge, which would keep the largest customers from zeroing out their allocated share simply by curtailing during peak periods. That provision could end up mattering more to the final bill than the peak count does.

Utilities will also have new considerations. Non-opt-in-entity DSPs will have to give ERCOT access to settlement-quality meter data for every large load customer in their territory, which in practice means new data pipelines and new reconciliation cycles.

Will ERCOT 12CP reduce transmission costs?

No, 12CP won’t lower Texas’s transmission bill. The transmission revenue requirement is set by what utilities build, not by how the cost gets divided. As NRG’s comments point out, transmission costs have climbed steadily throughout the life of the 4CP program, and that won't change under 12CP.

The real case for 12CP is fairness. The 4CP methodology was built for a grid that peaked on hot summer afternoons and behaved predictably the other nine months of the year, and that grid is gone. Winter peaks now rival summer ones, shoulder-season reliability gets genuinely tight when generators go out for maintenance, and always-on data center load has changed the nature of grid stress.

What large ERCOT electricity users need to do now

A 12CP ERCOT requires new considerations. Months that used to be ignorable are exactly the ones with the least operational history behind them. Shoulder-season peaks are lower, flatter, and less obviously timed than a 100-degree August afternoon.

The companies that come through this transition without a surprise on the bill won’t be the ones waiting for the PUCT to publish an effective date. They’ll be the ones already treating demand forecasting as a continuous twelve-month practice and building operating history in the months they used to ignore.

Frequently asked questions

What is coincident peak? A coincident peak refers to a business' electric demand during the highest-traffic periods on their local grid. Coincident peak programs vary by region.  

What is 12CP? 12CP refers to a grid operator program that charges large energy users according to their measured demand during the grid's highest-demand period each month. Some US grid operators like SPP and CAISO already use a 12CP framework, and ERCOT is moving from a 4CP program to 12CP.

How to avoid coincident peak charges? There are multiple strategies to reduce the demand charges or transmission charges associated with coincident peak programs, ranging from general energy efficiency to targeted load curtailment. Explore Demand Management Solutions.

Will Amperon have an ERCOT 12CP product? Yes, Amperon will be closely monitoring the proposed rule changes and will make adjustments to its Coincident Peak Alerts product accordingly.