Post: ERCOT alerts…explained

ERCOT alerts…explained

During the extreme summer heat or volatile weather conditions in Winter, Texas’ electrical grid can be put under strain. To help manage the supply of electricity with the demand, the grid operator ERCOT may ask Texans to conserve power during peak hours. At other times, they may issue warnings of conditions that may require future conservation or action.

Weather Watch

ERCOT issues a Weather Watch three to five days in advance of “significant weather” such as extreme heat with the potential to increase electrical demand.  

Voluntary Conservation Notice

This alert asks Texans to voluntarily decrease energy usage during peak demand periods, if it’s safe to do so. The goal is to decrease demand while ERCOT works internally to manage the grid as higher demand is forecast with a lower energy supply.

Conservation Appeal

ERCOT issues Conservation Appeals to ask residents, businesses, schools and governments to decrease electricity use if it’s safe to do so. This elevated request comes when higher demand and lower reserves are predicted and could require emergency operations.

Operating Condition Notice (OCN)

ERCOT describes an OCN as “the first of four levels of communication issued in anticipation of a possible Emergency Condition,” or “an operating condition in which the safety or reliability of the ERCOT System is compromised or threatened.”

An OCN is the warning that there are conditions present that may result in further action being taken in the future to protect the power grid, but there is not yet an Emergency Condition where ERCOT is asking Texans to conserve power or requiring utility services to shed load through controlled power outages.

Following an OCN, ERCOT may issue three other communications indicating the increasing likelihood of an Emergency Condition including advisories, watches and finally, an emergency notice to declare that ERCOT is operating in an Emergency Condition.

Energy emergency levels

When electricity demand is greater than the supply, ERCOT begins emergency operations to prevent an uncontrolled system-wide outage. To prevent uncontrolled outages ERCOT may issue calls for conservation, deploy reserves or implement controlled outages to reduce demand on the system.

When it issues an emergency alert, ERCOT can use additional power sources that may be available only during emergency conditions with the overall goal of keeping the grid functioning.

There are three levels of Energy Emergency Alerts and each level provides ERCOT with resources to protect the power grid.

• Energy Emergency Level 1: Operating reserves have dropped below 2300MW and are not expected to recover within 30 minutes. Conservation is critical and there is a risk of controlled outages. “ERCOT can call on all available power supplies, including power from other grids, if available.”
• Energy Emergency Level 2: Operating reserves have dropped below 1750MW and are not expected to recover within 30 minutes. Conservation is critical and there is a risk of controlled outages. “ERCOT can reduce demand on the system by interrupting power from large industrial customers who have contractually agreed to have their electricity turned off during an emergency.”
• Energy Emergency Level 3: Operating reserves have dropped below 1430MW and are not expected to recover within 30 minutes. Conservation is critical and controlled outages are underway. “ERCOT will order transmission companies to reduce demand on the electric system. This is only used as a last resort. This is typically done through [controlled] rotating outages and temporary interruptions of electric service. In extreme circumstances, more prolonged outages may be required.”

Looking ahead

NERC’s latest reliability assessment noted that the ERCOT assessment area is forecast to experience continued rapid electric demand growth over the next 5–7 years.

Forecast summer peak total internal demand is expected to increase from 94,650MW for 2026 to 154,077MW for 2035, an average annual increase of 5.6%. This load growth is mainly driven by forecasted interconnections of large loads totaling 45GW by 2030, of which 23GW are data centers. For Summer 2026, demand response (DR) contributes 13.3GW to resource adequacy (up from the 2.7GW projection in the 2024 assessment), and contributions from DR rise to 53.1 GW by 2030.